Introductory AstrSolar System
Introductory AstrSolar System ASTR 111
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This 156 page Class Notes was uploaded by Khalil Sawayn on Monday September 28, 2015. The Class Notes belongs to ASTR 111 at George Mason University taught by Robert Weigel in Fall. Since its upload, it has received 180 views. For similar materials see /class/215140/astr-111-george-mason-university in Astronomy at George Mason University.
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Notes Reminder After lecture I post a revised version of the notes with Revised in the filename These contain added text and solutions to the problems You probably don t need to print it out if you attended class Outline for 18 September Tuesday Light Chapter 5 of text 60 minutes Problem solving techniques and exam prep suggestions 15 minutes Outline for 18 September Tuesday Light Chapter 5 of text 60 minutes Problem solving techniques and exam prep suggestions 15 minutes Key Words frequency wavelength absorptionemission spectrum Determining the Speed of Light Galileo tried unsuccessfully to determine the speed of light using an lantern on a distant hilltop Light travels through empty space at a speed of 0 0000 kms in 1676 Danish Eanh neatlupiker astrunurner we observeeclipse Claus Mme Mmpiler smaans awed that eavlievlhan expemd the examime uf Jupitertu Ear h mm m rmm Jupiter we observe eclipses a Jupiter39s moons later man exvemd t Stationary mirror 1 Deflection A angle L Light source Observer Suppose experiment is done in water Where to move your eye 77 Stat39onary mirror Deflection 4 g a gle l Light source Observer M4 Suppose experiment is done in water Where to move your eye 7 J r J Stationary mirror Deflection A angle U Light source Observer 11 fr Light is fast In order to measure its speed you need Big distances Creativity Light is electromagnetic radiation and is characterized by its wavelength A Snnmmlallsanxcmen 700 mu Prism breaks light im its mumm m Imam slt mlmv nmm gh ammm rm lighllnwmmmmm 1 Why the sky looks blue The atmosphere scatters blue light more effectively than red light Blue hence mostly red light reaches Blue your eye when you look through a thick slice of atmosphere at the setting Sun 5 b Why the setting Sun looks red Angle of light as it goes from one medium to another depends on color This can be used to explain Rainbows Red Moon Red sunset Wavelength and Frequency are Related wavelength gt c velocity frequency V gt is the number of cycles per second pass a glven pornt Wavelength and Frequency are Related waveleng1h e p veloclly lrequency F Is the number of cycles per second pass a given point snagmuh pm I quotmuqr urn E o quotm 51 Because of Its electric and light is also called electromagnetic radiation d g Asible light falls in the 400 to 700 nm range Stars galaxies and other objects emit light in all main wave mu Iwnm y m I wavelengths m mum um km wavelength magnetic properties The dual nature of light Particle Wave Particle Question what would you expect if you used yellow spray paint slits Screen is You would expect something like this Slits Screen E or Depending on slit separation Slits Screen i Now use light interference pattern not consistent with particles Bright bands here light waves from the 5quot two slits reinforce each other Screen Laser light Dark bands where light waves from the two slits cancel each other Therefore To understand experiments light can often be thought of as a particle Some experiments show behavior that cannot be explained by particle picture need to use waves to explain Probing the atom Gold foil seen edgeall Most particles get through Therefore Rutherford s experiments helped show that an atom has a small dense nucleus composed of protons and neutrons An atom can only absorb special photons eus of an atom i surrounded by electrons that occupy only certain orbits or energy levels When an electron jumps from one ener y level to another it emi s or absorbs a photon of appropriate A M energ and hence of a specl lc wavelength The spectral lines ofa particular element correspond to the various electron transitions between energly levels in atoms 0 that e em ent Photons have energy but only special energies Planck s law relates the energy of a photon to its E energy of a photon h Planck s constant c speed oflight 9 wavelength oflight E hc frequency or wavelength Side note Three Temperature Scales Kelvin Celsius Fahrenheit a 23 gt Boiling pointnlwaler Preexing point ulwuter V 7 Absolute ma Sun39s or temperature Sun39s sultan Kemperaluv Color and Temperature Blue Hot or Not httpwwwstraightdopecommai bagmhotflamehtml An opaque object emits electromagnetic radiation according to its temperature bl kl J V l absorb light that is at the temperature of my body part I reflect light that is not at the me temperature as my body part Although this is actua y a false Mme details aimip mm mp urWEJab V lf blue light has higher energy and energy is proportional to t 39 perature why are my cold What you see depends on if it is a result of Absorption light reflected off your face or light reflected by a plant Emission light from a flame or a heated bar Astronomy 111 Section 001 Fall 2006 Examination 2 R V1 W Revised Version includes seme solutions and a few corrections Exam 2 will have 50 questions 25 questions will cover knowledge of the keyword de nitions listed in the lecture notes the equations or the scaling equations see below for a list 25 questions will be based on topics and concepts covered in the lecture Many of these topics and concepts are covered by questions on the following pages As you go over these problems try to classify them as de nition concept scaling or a combination thereof For the concept questions make sure you know what physical principle the question is testing your knowledge of On questions 6 7 and 17 I give example of what I mean by this 00 O 0 Equations and scaling relationships the equation that relates photon frequency to wavelength the relationship between density mass and volume how photon energy scales with wavelength how energy ux from a blackbody scales with temperature how the wavelength of the peak energy in a blackbody scales with temperature Keywords absorptionemission spectrum blackbody flux Doppler shift refractionre ection convergingdiverging lens focal point angular resolution magnification chromatic aberration Scaling Parallax Escape speed Jovian planet Comet Asteroid Meteoroid i i w i I eenlionse e 39ect greenhouse gas solar wind plasma magnetosphere nonhu and somlmn lights ozme ozme layer Van Allen Radiau39m bdts 0 I I I l I I I I I I I I I I IA B D2 020 C E n 015 u I 5 5 010 7 E t n D 0 005 o o IIl I39jl39 0 02 04 06 081011141618 20 22 24 28 28 30 30 Wavglength pm a nosphere and one was measured on me ground A Figure 2 Light beams A B and c are createdby a source to the le The dark area 1 cm Hellecled So ar namamn H w m Renwen by mums ems l and x a 40 mm m Almasphenc A mosvhers ms andow Absorbed by 37 Amaspnam Greenhouse Gasas 32 Back Radvauo m 390 3969 2 7a Su aca man hv Wm mamas Evapor amehon 324 mspwamn Absmbed by Sunsce Figure 3 In January the nearby star appears to be here I Earth quot July Figure 4 Parallax of a nearby star Lecture 10 Chapter 5 lIf an object is a perfect blackbody then a it emits no energy b it emits energy only at certain wellde ned wavelengths called spectral lines c it emits energ with a continuous distribution that peaks at a certain wavelength dependent upon temperature This is a de nition problem Answer a is a misconception about blackbodies When you think of blackbody you may think of blackhole an astronomical object from which nothing can exit Both have the word black but energy can escape from one of them Answer b may seem right because we talk about the sun being a blackbody but when we look at its spectrum we see spectral lines see Figure l in its blackbody curve However the sun is only approximately a blackbody 2A perfect blackbody is socalled by scientists because a V it absorbs all energ falling upon it and emits a character39stic spectrum of radiation Whose intensity as a function of wavelength depends only on its temperature it absorbs all energy falling upon it and emits no energy at all hence its name the shape of the spectrum of energy emittedby it has a xed shape independent of temperature and only the emitted intensity at each wavelength changes with the black 88 body39 s temperature This is a de nition problem b is half true it absorbs all energy falling upon it The second part ofb is false see question 1 c is false because a blackbody has a curve for each temperature 3A blacksmith heats a piece of steel until the wavelength of maximum emission of radiation is measured to be 1 mm correction 1 pm in the infrared part of the spectrum How would he have to change its temperature in order that this peak wavelength would move to 05 mm correction 05 pm or 500 nm in the visible spectral range a He would have to cool the steel to half its temperature b He would have to raise the temperature by a factor of 24 correction 24 or 16 c He would have to double its temperature This is a De nition and Scaling problem Try to draw two blackbody curves that illustrate this when I copied and pasted this two typos were introduced Can you spot them First problem wording ofthe sentence implies 0 5 mm 500 nm but 500 nm 500 x 10399 5 x 1039 and 0 5 mm 0 5 x 10393 5 x 10397 m resolution is that it should read 0 5 pm andthe 1 mm should be 1 pm Second roblem answer b implies 24 16 The resolution is 2 16 Lesson when cutting and pasting Greek letters and superscripts don t convert properly Now that the typos are xed we can answer the problem Wien s law says km N lT or T N 1 Arm lfit starts at 1 pm 10396 m then T1 N 110396 106 and we want to get it to T2 N 15 X 10397 m 02 X 107 2 X 106 The ratio T2T1 is 2 so we need to double the temperature I 4The energy emitted per second by the Sun is greatest at a wavelength of about 500 nm The energy emitted per second by a star having half the temperature of the Sun would be greatest at a wavelength of about I a mmunmeinrrared b 8000 nm in the in ared range 16 times 500 mm c 250 nm in the near UV Formatted Font Not Bold Correction the original version of this had 250 nm selected as the solution and the e lanation answere e uestion as if it asked about a star havi double the temerature The Question and solution now match This is a De nition and Scaling problem The de nition is the Wien s law which says Arm N 1T orT N 1 7am T1 N 1500 nm and ifwe want ERG double T1 we need to change 500 nm to 250 nm Note StefanBoltzmann law which says the total energy including all wavelengths emitted by a blackbody is proportional to its temperature to the fourth power F N T does not apply here The question is asking about the energy at one wavelength only 5 Suppose the Sun had a temperature of 17400 K three times its present temperature but had the same size that it has now How much more energy would the Sun emit per secon a 9 times more b 81 times more c 3 times more The StefanBoltzman law is Energy uXN T4 34 322 92 81 Wait The problem asks about energytime and the StefanBoltzman law is for energy uX What is going on To answer this consider how is uX related to energy per time If you were measuring the amount of energy per second collected by say a solar panel you would say the energy uX EnergytimeArea of panel In this problem the area does not matter because you are not changing the solar panel that collects it You are only changing the energytime in the equation 6 In a beam of radiation from a blackbody the amounts of energy per second at an ultraviolet wavelength UV of 300 nm and at an infrared wavelength IR of 800 nm are found to be equal In this beam how do the numbers of photons per second at each of these wavelengths compare a There will be more UV photons than IR photons b There will be equal numbers of photons at each of these wavelengths c There will be more IR photons than UV photons This problem has two aspects Scaling the energy of a photon is inversely proportional to its wavelength ENlA So a UV photon has more energy than an IR photon Concept Physical principle is ux 7 the amount of stu that passes a point per unit time In this case the stuff is photons 7In Figure l which curve represents an ideal blackbody 3 Curve A b Curve B c Curve C De nition The ideal blackbody curve is smooth 8In Figure 1 what is the intensity of curve B at 550 nm a Impossible to tell39 550 nm is not shown in this gure Nearest 02 Nearest 01 Nearest 005 Nearest 00 De nition 550 nm 055 pm and read the graph 055 pm give an intensity of about 022 SV 9If the object in Figure l were increased in temperature what would happen to curves A B and C a All would increase Formatted Font Bold Font color Auto b All would decrease c A and C would decrease B would increase Defnintion and Concept De nition Energy radiated both total and at all individual values of wavelengths by a blackbody increases with temperature Concept All curves are measuring the same object so they should all do the same 39 10In Figure 1 Curve C is more jagged The locations of dips in curve C correspond to Spectral lines of a blackbod Spectral lines of atmospheric molecules Instrumentation error Diffraction lines Spectral lines of the lens used to convert the light into colors Concept The intensity of photons electromagnetic radiation you receive from the Sun is affected by the atmosphere which acts like a lter Atmospheric particles absorb electromagnetic radiation with special frequencies or wavelengths At these frequencies there will be a drop in the curve De nition If you did not know the answer was b you need to know the de nition of a blackbody rule out a as a possible answer SLESSS llVenus Correction This should read Mercury because Venus has an atmosphere you may have heard about the clouds of Venus has no atmosphere If you measure the solar spectrum from its surface a Curves B and C in Figure 1 would not change b Curve C would look less like B in Figure l c Curve C would look more like B in Figure 1 d Curve B would be more jagged in Figure l e Curve C would be more jagged in Figure l 12White light is composed of a Equal intensities of all colors of the rainbow b Unequal intensities of all colors of the rainbow c Equal number of photons of all colors of the rainbow d Unequal number of photons of all colors of the rainbow e Equal numbers of red green and blue photons See Figure 51 1 in your text page 99 Intensity at solar radiation at visible wavelengths corresponding to different colors is not the same for all colors l3Does a blackbody have color a Yes and they all appear the color of the sun b No you cannot see a blackbody c Yes but its depends on its temperature d Maybe it depends on if it is an ideal blackbody l4Why do different elements display different patterns of lines in their spectra a they emit or absorb photons with different frequencies b they have a different number of neutrons c light passes through them at different speeds d they have a different number of protons 15lf the temperature of a blackbody increases by a factor of four what happens to the total energy ux it radiates a b c d e f Need more info Energy flux N T4 44 422 162 256 Lecture 11 Chapter 6 16 In Figure 2 where is the light source located 1 km to the left b 1 cm to the left c 1 nm to the le d 1 km to the right Concept Rays of light from far distances are nearly parallel Principle 1 km is much smaller than 1 cm the height of the object according to the caption Suppose the height of the object was 1 nm Could the answer be b Yes In this case 1 cm and 1 km are both distant in the same way that two stars may be far separated but when viewed from Earth they are both distant 171n Figure 2 what happens to beam A when it enters the glass a It continues straight It re ects back It re ects up See the following gure or the lecture notes to see how to zoom in on a surface and then use the principles of optics to tell you which way the light will bend SV Line A bends toward the normal normal When a light ray goes from air into glass or water it bends toward the normal 181n Figure 2 what happens to beam C when it arrives at the glass a It bends down and to the right b It re ects up and to the left c Both of the above d Both of the below e It bends up and to the right t It bends down and to the right 19Does any ofthe light from Beam A in Figure 2 get re ected a Yes down and to the left b Yes up and to the right c Yes up and to the left d No 20 In Figure 2 if the light area represents glass and the dark area represents air what happens to beam A when it enters the air from the glass beam A is still going from le to right a Continues straight b Bends up c Bends down d Re ects along same direction In class I skipped this problem because the wording did not make it clear that beam A was still coming from left to right Below is a diagram that helps answer this question I have reversed the colors in Figure 2 to emphasize that the light ray beam is going from glass to air The optics rule that you should remember is that when a ray from air is incident on a surface such as glass or water at an angle to the normal the ray bends towards the normal If the ray is going from glass or water to air the ray bends away from the normal In the lecture notes I show this pictorially with a at surface To draw the normal line for a curved surface zoom in until the surface looks almost at Zooming in makes the surface look at in that same way that from space an astronaut would say the Earth looks curved If he zooms in with a cameral or comes back home he would say the Earth looks at Dashed line is path of line A if it does not bend Line A bends away from the normal 21 Why are telescopes put in orbit a Reduce the in uence of light pollution b So they are closer to the stars c Both of the above d They are less expensive because they are computer controlled Why isn t it b or c 22A ash of light is transmitted simultaneously through two parallel tubes of length 1 km one evacuated the other lled with water Detectors sense the arrival times of the light ash at the ends of these tubes What will be the relationship between arrival times of these light ashes a The ashes of light will arrive simultaneously at the ends of the tubes because light always travels at the same speed b The ash will arrive earlier through the water lled tube c The ash Will arrive earlier through the evacuated tube 23A er passing from the vacuum of space through a piece of glass and then passing back into the vacuum photons of light will be traveling a slower than when they entered the glass because they will have been slowed down by their passage through the glass b faster than before they entered the glass having been accelerated by their c passage through the glass Correction The sentence that was here should be moved down and labeled as answer d d at the same speed as When they entered 24Which way does a light ray bend when it strikes the at surface of a block of glass obliquely ie at an angle to the surface and passes into the glass a Toward the perpendicular to the surface making a greater angle to the su ace b A light ray does not change direction when it passes into the surface of the glass because the surface is at Light rays change their directions only through curved glass surfaces c Away from the perpendicular to the surface bending toward the surface making a smaller angle to the surface 25How much more light does a 2 cm radius lens capture than a 1 cm radius lens a Same b Two times c Four times d 16 times 26Many fortunate amateur astronomers have telescopes with primary mirrors 20 cm in diameter The recently built Keck telescopes on Hawaii have mirrors 10 min diameter How much more light is collected by one of the Keck telescopes compared to the amateur39s telescope a 2500 times greater b About 7 times greater c 50 times greater 27ln the primary mirror of a re ecting telescope light of different wavelengthsisuch as red and blue light from a stariare focused a with the red focus closer to the mirror than the blue focus b with the blue focus closer to the mirror than the red focus c at the same point Correction The original version had b which is incorrect Chromatic aberration occurs when light of different wavelengths refracts a different about as it passes through a lens In this case we are talking about a mirror and the angle of re ection does not depend on wavelength 28What is diffraction of light a h spreading out of light waves after they pass through an opening such as the outer diameter of a lens or mirror b The bending of the path of a ray of light as it passes from one transparent medium to another39 for example from air to glass c The distortion in the image when light passes through a lens or re ects from a mirror due to imperfections in the lens or mirror surface 29A factor that has become much worse for many observatories and now severely limits the number of useful sites for astronomy in the world is a light pollution due to the increasing size of nearby cities b the number of satellites in orbit which disturb observations when they pass in front of the object being observed c the weather which has deteriorated signi cantly due to global warming d greenhouse gasses which block the starlight 30A er passing from the vacuum of space through a piece of glass and then passing back into the vacuum photons of light will be travelin a slower than when they entered the glass because they will have been slowed down by their passage through the glass b faster than before they entered the glass having been accelerated by their passage through the glass c at the same speed as When they entered 31At what distance from the objective lens in a refracting telescope is the image formed ie where would the photographic lm or electronic detector be placed A immediately behind the lens to collect the most light B its diameter C its focal length D twice its focal length 32To correct for chromatic aberration in a refracting telescope a corrective lens is mounted next to the objective lens In this corrective lens A red light bends more than blue light B blue light bends more than red light C all colors bend the same amount D no bending is experienced by any of the colors 331n the re ection of a light beam from a at mirror the angle between the incident and re ected beams relative to the perpendicular to the surface of the mirror is A equal to the angle between the incident beam and the perpendicular B equal to 2 the angle between the incident beam and the perpendicular C always a right angle or 90 D twice the angle between incident beam and the perpendicular 34How much more energy does a 2 cm radius circular light collector absorb than a 1 cm radius collector a S b 2X c 4x d X e Need more info Lecture 12 Chapter 7 351f the radius of Earth was twice as much and its mass was the same what would its density be a 2 as muc b 4 as much c 18 as much d Same e 2x as much f 4x as much g 8x as much 36 In Figure 4 it says the star appears to be here To be more speci c it should say appears to be here with respect to a the distant stars b other nearby stars c the Sun d the Moon The distant stars don t move so they are used as a reference point 37 If the nearby star in Figure 4 was the same distance from Earth but in the ecliptic plane would there still be parallax a Yes and much smaller than that shown in Figure 4 b Yes and about the same as that shown in Figure 4 c Yes and much larger than that shown in Figure 4 d No 38 If the nearby star in Figure 4 is farther away d increases what happens to its parallax as viewed from Earth a Increases b Decreases c Stays the same d All of the above 39 As the Earth rotates on its axis does the apparent position of the star change a Yes more than that shown b Yes less than that shown c No d Yes but the same amount as that shown 40 If Figure 4 showed the position of Earth in March and September how would the angle p change a It would be nearly the same b It would be twice as much c It would be half as much d It would be exactly the same 41 In our solar system which of the following planets is not a member of the Jovian group A Mars B Saturn C Neptune D Jupiter 42 Suppose that observers using the Hubble Space Telescope detect around several solartype stars the presence of planets with the following characteristics low density large size polar diameters shorter than equatorial diameters uid surfaces rapid rotation How would these planets be classi ed in terms of our solar system A asteroids B terrestrial planets C comet nuclei D Jovian planets 43 Most of the planets orbit the Sun on or close to the lane containing both north and south celestial poles and the zenith at Greenwich England B plane of the Milky Way galaxy C equatorial plane D ecliptic plane Which of the following general statements about all of the planets in the planetary system is true A They have hard rocky surfaces which can be seen and photographed B They orbit the Sun in the same direction C They have satellites or moons D They have very dense atmospheres Viewed from the Earth which planet has the smallest angular size A Mercury B Mars C Jupiter D Pluto Determination of the chemical composition of the atmospheres of the planets is carried out most effectively by what type of stud A photometryithe measurement of the fading of light from their moons as they pass behind the planet s atmosphere B measurement of their relative mean densities C measurement of their atmospheric temperature D spectroscopy the measurement of absorption features in their spectra When astronomers look for evidence of hydrogen gas in the spectra of the Sun planets and nearby stars the positions of the spectral features or quotlinesquot due to hydrogen A are always in the same pattern characteristic of hydrogen gas as seen in the laboratory B change systematically depending on the distance from the source starting with a laboratory pa em C are in the same pattern for solar and planetary sources but very different for stars at larger distances because of absorption of light by the interstellar matter D are in a very different pattern depending on the location of the planet or star and reproduced only with dif culty in the laboratory The asteroid belt is made up of A large rocky bodies typically about the size of our Moon B rocky bodies from a few meters to tens of kilometers in diameter C several planetsized objects with dense methane atmospheres D irregularly shaped bodies composed primarily of ices A typical asteroid is made of A ices of water methane and ammonia or perhaps ices with dustsized grains of rock mixed in B ice with a liquid water core C rock and meta D rock and ice What is the basic difference between comets and asteroids A Comets always emit their own light while asteroids only re ect sunlight B Comets always move in open orbits around the Sun visiting the Sun only once in their lifetime while asteroids move in closed orbits C Comets are mostly composed of ices While asteroids are mainly composed of roc s D Comets are spherical while asteroids are mostly irregular in shape 51 The craters on the Moon are all nearly circular Why is this A ost of the craters on the Moon were forrnedby volcanoes and this results in circular craters B It is believed that the objects that formed the impact craters on the Moon39s surface all struck the Moon approximately perpendicular to its surface and this would result in circular craters C The objects that produced the impact craters came in at a variety of angles but the craters were actually made by the shock waves generated by impact and this results in circular craters D The objects that produced the impact craters had been rounded by many previous collisions in space and round objects produce circular craters regardless of their direction of impact Lecture 13 amp 14 Chapter 9 52 In Figure 3 what should the number in the circle be a b c 136 d 9 There are two ways to answer this The rst is to take 1654030 235 The second uses a concept discussed in class the amount of solar radiation energy in per time interval must equal the amount of radiation out per time intervalquot otherwise the temperature of Earth would be increasing So if you were not given the numbers 165 40 and 30 you would need to say input 342 output from albedo 107 output from everything else To balance this output from everything else must be 235 Note that I did not say the amount of solar radiation out The ougoing radiation does not have the same characteristic Flux vs wavelength curve There is more long wavelength radiation going out How is this related to greenhouse gasses The total ux is the same area under the ux vs wavelength curve but the curves are a little different Can you draw this 53 In Figure 3 is energy transfer by therrnals rising hot air is primarily a Conduction b Convection c Radiation d None of the above 54 In Figure 3 the amount ofsurface radiation is listed as 390 What are the units a Wmquot2 Note mquot2 is the lazy way ofWriting m2 b Watts c Joules d Joulessecond 55 The greenhouse effect is the a absorption of solar ultraviolet radiation by gases in planetary atmospheres leading to atmospheric heating b absorption of solar infrared radiation by the atmosphere and the subsequent heating of a planet39s surface c protection of the surface of a planet from harmful infrared rays by atmospheric gases d absorption by atmospheric gases of infrared radiation emitted by a planet that has been heated by solar visible and ultraviolet radiation 56 Energy calculations that simply equate the in ux of solar energy on Earth with the out ow of energy from Earth lead to a very low average equilibrium temperature for Earth of around 27 C or l6 F which is much lower than the actual average surface temperature of Earth 9 C or 48 F What mechanism explains this discrepancy between the simple prediction and observation 60 planet 61 A kinetic energy of meteoritic material that is dissipated in the atmosphere as the particles are stopped by friction B chemical action between molecules in Earth39s atmosphere C the greenhouse effect the capture by gases in the atmosphere of heat radiation that would otherwise escape D extra energy conducted outward from the hot interior of Earth Which of the following is the major power source that drives the dynamics of Earth39s atmosphere A out ow of the original heat of production from Earth39s interior B tidal effects from the Moon and Sun C the burning of fossil fuels such as coal oil and natural gas on Earth39s surface D solar radiation The albedo of a planet is the fraction of energy that is A reradiated into space as infrared radiation by the planet B re ected by the Whole planet including atmosphere and surface C absorbed D re ected by clouds in the atmosphere What is the main mechanism by which the lower atmosphere of Earth is heated A Sunlight heats Earth39s surface and the resultant heat is transferred to the atmosphere by infrared radiation and convective gas motions B Conduction carries heat from Earth39s interior to the surface where conduction in the lower atmosphere transfers this heat to the higher layers C friction between the winds in the atmosphere and the mountain ranges and land masses of Earth D absorption of sunlight by molecules of the gases of the atmosphere Which of the following molecular species plays a major role in the greenhouse effect in ary atmospheres A ozone B nitrogen C carbon dioxide D oxygen The Earth has a temperature and thus emits radiation somewhat like a blackbody What is the source of the energy for this radiation A incoming radiation received from the Sun B heat retained by the Earth39s interior since it was created by the collisions of planetesimals C heat from radioactive decay deep within the Earth D tidal friction The Earth39s albedo is 039 The total amount of radiant energy emitted rather than re ected by the Earth is thus A 39 of the incoming radiation from the Sun B 61 of the incoming radiation from the Sun C 100 of the incoming radiation from the Sun D actually slightly more than 100 of the incoming radiation from the Sun because of the Greenhouse effect What is the basic structure of Earth39s interior A solid iron inner core molten iron outer core rocky mantle lighter rocky crust B molten iron inner core molten rocky outer core solid rocky mantle lighter rocky crust C molten iron core molten rocky mantle solid rocky crust D molten iron inner core solid iron outer core rocky mantle lighter rocky crust Earth39s interior received its heat energy from the impacts of planetesimals and from radioactivity This heat energy is gradually radiating into space As the Earth39s interior continues to cool we can expect that in the distant future the inner core will become molten like the outer core B the outer core Will become solid like the inner core C the mantle will become molten while the core will become solid D the entire interior will become one homogeneous solid Earth is not thought to have a permanent magnet in its interior because the A magnetic eld reverses direction over periods of tens of thousands of years B magnetic eld distribution in space around Earth does not match that of a permanent magnet C rotation of Earth quickly destroys the properties of a permanent magnet D core is not made of magnetic material Earth39s magnetic eld originates in A a solid permanently magnetized core in the interior of Earth B intense electric currents owing in the Van Allen belts within the magnetosphere of Earth C the tidal ebb and ow of electrically conducting seawater in Earth39s oceans D slowly moving currents of molten iron Which produce electric currents in the deep interior of Earth Earth39s magnetic eld is caused by A electric currents owing in the molten core B the motion of the electrically charged particles of the solar wind as they pass the E rth a C a solid iron magnet in its interior D electric currents owing in the ionospheric layer of its atmosphere Earth39s magnetic eld is generated by A permanent magnetism in Earth39s cmstal rocks B electric currents in Earth39s core C electric currents in Earth39s mantle D the ow of electrons and ions in Earth39s magnetosphere Earth39s magnetic eld is thought to be caused by A the ow of solar wind particles around and within its outer atmospheric regioni the ma netosphere B electric currents owing in the liquid core C localized magnetic anomalies near the Earth39s surface D a magnetized solid iron core in the interior Suppose that the Earth was somehow put into orbit around a cool star cooler than our Sun at the right distance for our oceans to remain liquid so that life could still exist but the star emitted no UV radiation Which of the following statements would most likely be FALSE A Our ozone layer would disappear B Our magnetosphere would disappear C Our therrnosphere would disappear D We would be closer to the star than we are to our present sun What protects us from the damaging radiation effects of the highspeed solar wind that ows through interplanetary space A the rapid rotation of the Earth which de ects most of the solar Wind E the Moon Whose gravitational eld shields us from the solar wind C Earth39s atmosphere D the Earth39s magnetic eld The Van Allen belts are A regions of the Earth in which no seismic activity is detected from earthquakes B dense collections of small rocks surrounding the major lanets C two doughnutshaped rings of charged particles surrounding the equatorial regions of Earth at very high altitudes D undersea mountain ranges in the centers of the oceans Aurorae on the Earth are caused by A electrical currents in the ionosphere generated by dynamo action in Earth39s core B charged particles from the sun moving through Earth39s magnetic eld and striking the upper atmosphere C the re ection of sunlight from arctic and antarctic ice into the polar night skies D ultraviolet radiation from the Sun ionizing atoms in the upper atmosphere One of the major differences between Earth and its neighboring planets Venus and Mars is the lack of large quanti es of C02 in its atmosphere If all three planets were originally formed with signi cant quantities of this gas in their atmospheres Where is the majority ofthis C02 on Earth at the present time A It is dissociated by UV and visible sunlight into carbon and oxygen that now exist in abundance as separate chemic s B It is concentrated high in the atmosphere where it contributes to the greenhouse e ect C It is dissolved in seawater a situation that cannot arise on the neighboring planets D It is locked up in carbonate and carbonrich rocks and minerals formed in the sea and on Earth39s surface How does the temperature of Earth39s atmosphere vary with height over the range 0 to 120 m A It remains approximately constant at room temperature over the whole range B It always remains well below the surface temperature C It decreases and then increases two or three times D It rises steadily until it reaches a high and constant value above 120 km In which layer of Earth39s atmosphere does all weather occur A thermosphere B stratosphere C mesosphere D troposphere In which layer of Earth39s atmosphere is the ozone layer located A stratosphere B mesosphere C thermosphere D troposphere The temperature in the stratosphere increases with increasing altitude because A it is heated by solar infrared radiation absorbed by carbon dioxide and water vapor B it is heated by the absorption of solar ultraviolet radiation by ozone C charged particles from the magnetosphere collide with atoms in the stratosphere depositing energy D these higher altitudes are closer to the Sun Earth39s stratosphere is warmer than the layers above and below it because A warm air heated by contact with the ground rises into the stratosphere thereby heating it B C02 in the stratosphere absorbs infrared light radiated outward by the ground C the methane released when we burn fossil fuel absorbs infrared light in this layer D ozone in the stratosphere absorbs ultraviolet radiation from the Sun One might expect the dominant circulation in Earth39s atmosphere to be one large convection cell in each hemisphere with air rising at the equator due to solar heating moving toward the poles at high altitude cooling and sinking then returning toward the equator along the surface The actual circulation is more complicated than this primarily because of the A speed of rotation of Earth B uneven heating of oceans and continents by the Sun C escape of heat outward through Earth39s crust D uneven heating of the different atmospheric layers by the Sun Which of the following is NOT a major factor in the in uence of humans on global warming A increase in heat added by the bodies of humans and animals as their populations increase rapidly B use of gasoline petrol and natural gas in transportation vehicles such as cars ft and arrcra In the news Moonquakes lv i 1 nnn km Snlid mnespnm Crust Plastic asthenosphere In the news Moonquakes Four types of vibration Deep mu km neiowsurraee tides Vibrations meteorites mai expaneion after deep freeze 39 ShaiioWOEIeSEI km heiow surface 197271977 28 upto 5 5 on Richter scaie we 1 Outline for 14 November Tuesday Jupiter and Saturn Orbit Sur ce w a R Atmospheres gravity and escape velocity Atmospheres gravity and escape velocity Atmospheres m we m 39 imminmmmw mmw1em a WWW m twinge Listsrum Newman v girl 52 ewemg W 39 v mmmmm 51mm the mm me warm musmmm mmanme Atmospheres Atmospheres The rapid rotation ofthe planets twists the clouds into dark belts and H ht zones that run parallel to the equator The visible surfaces of Jupiter and Saturn are actually the tops oftheir Atmospheres The outer layers of both planets39 atmos eres show differential rotation tunal regluns rutate slightlyfastertnan the pular regluns The chemical composition of Jupiter and Saturn is hard to measure Why Atmospheres m For both Jupiter and Saturn the polar rotation rate 395 Pearlylhe We Spacecraft images show as the Internal rotation rate remarkable actIVIty in the clouds of Jupiter and rumma Swill Adm billhlurmumtd Wavrrlwscwiullnllu mm rim nan H mmquot m 59 amr alum1m a Picnmr r L rmth rm b www12me I979 cl sthhmury1995 Storms wirmmgma The colored ovals quotquotquot quotZquot visible in the Jovian 17m 2393239 atmosphere represent gigantic storms k I L Some such as the Great Red Spot are quite stable and persist for many years win11 m m a m m m 7 mm 14 x quotmm s quotmm Brown uvIs Evenlyxpamdwhileovals Storms in Saturn s atmosphere seem to be shorterlived In the news Hurricane on Saturn mtg saturrr glnasa guvmultrmedravrdeusvrdeurdetarls dm7vrd2ulDZlSE Hurricanelike vortex at Saturn39s south pole where the vertical structure of the clouds is highlighted by shadows Such a storm with a welldeveloped eye ringed by towering clouds is a phenomenon never before seen on another planet lxopopouss Kr Both Jupiter and Saturn emit more energy than they receive from the Sun What does this tell us The internal heat of Jupiter and Saturn has a major effect on the planets atmospheres m lnlvredlmg oi uoioruionum If Jupiter and Saturn formed at the same time which should be emitting more heat Saturn s atmosphere contains less helium than Jupitei s atmosp ere This lower abundance may be the result of helium raining dovmward into the planet Helium rainfall may also account for Satum s surprisingly strong heat output Salum has lower mmoiwhwri Kempemlure J man Mullen Outline for 14 November Tuesday Jupiter and Saturn Orbit Sur ce Atmosphere Saturn s rings are composed of numerous icy fragments while Jupiter s rings are made of small rocky particles am Ynlupllu l A Low notquot Tno principai rings of Saturn are composed of numerous particies or ice and icercuated ruck ranging iri size frum a few micrumeterstu about in rn Jupiter sfaintrings are composed Ufa reiativeiy smaii amuuntu smaii dark rocky paniciesthatrefiectvery iittie iight Earthbased observations reveal three broad rings encircling Saturn 274cao km Why can t the rings be solid Roche limit lmages mm mm Hen wklpedla avgwkvmchsjwm Something is Fishy How can a planet be solid e 39 Rm 5mm 39 gainquot L g wrapquot 01 huh mugs seen u R as sun 9 edgun Salum l5 clvcled by a sys12m unmn bvuad was lying mm plane mum planet s equaluv This sys12m lsimed awaylmmlhe plane ulSalum s uvbll whlch causeslhe vmgslu be seen alvavluus angles by an Eavlhrbased ubservev uvevlhe cuuvse u a Salumlan yea Pebbles snowballs and boulder size How was this determined Casslnl divlsm Frlng n Encke gap Musl um Wigs ml mm m Rum hm ulSalum wheve dlsvuplwelldal mes ave shungevlhan me gvavllalmnalluvces emaclmg me my pamcles in each ulhev Each ulSalum s map was is cumpused ula gveal many nanuw vmglels The few F hhg Whmh sjus t eutsme the A mg l kept narruvv by the gravltatmnal pull er shepherd satelhtes Saturn s rings consist of thousands of narrow closely spaced ringlets a my a lounge wequot Saturn s inner satellites affect the appearance and structure of its rings mm m 1 V M m m Lani mm quotquot Bush Vows To Put Man On Moon Before It Disappears At End Of Month January a 2mm Issuuml IGTl 1N nu Man mew rm mumd slur lull ml mued Nuns tlliln murmur n u mmm In fuw ii I mu r Ittlw umm rc moon alum u l s m a Outline for 07 September Thursday Review of Syllabus 5 minutes Review topics from Lecture 13 Chapters 1 and 2 of text 10 minutes Understanding the movement and appearance of the moon Chapter 3 of ext 60 minutes Homework and Quizzes There are no quizzes for the lecture and I will not collect homework At the end of each lecture I will suggest a list problems from the textbook and problems on the quotself quizquot available on the textbook CD or the texbook web page Exams How I write exams How I would study for my exam Good study techniques Write your own questions Explain why answers are correct and incorrect Given image be able to explain main features Outline for 07 September Thursday Review of Syllabus 5 minutes Review topics from Lecture 13 Chapters 1 and 2 of text 10 minutes Understanding the movement a appearance of the moon Chapter 3 of ex 60 minutes Outline for 07 September Thursday Review of Syllabus 5 minutes Review topics from Lecture 13 Chapters 1 and 2 of text 10 minutes Understanding the movement a appearance of the moon Chapter 3 of ex 60 minutes Eventually we want to be able to explain Guiding Questions Why does the Moon go through phases Doesthe rnoon rotate ts there such a thtng as the dark stde orthe Moon What ts the dtrrerenoe between a lunarecltpse and a Solarecltp5e7 What ts the dtrrerenoe between a total and annular ecllpSe been JV w ollert do lunar eottoses happen When one ts taktng place where do you have to be to see lt w ollert do solar eottoses ha en Why are they Vlslble onw rrorn oertatn soeotat tooattons on Earth Key Words solar corona solar eclipse total eclipse annular eclipse apogee umbra perigee penumbra sidereal month 39 new moon synodic month 39 fUII moon A simple model Moon executes circular orbit Moon orbit is in Earth s ecliptic plane W 3 9 O A a quotNewquot quotFirsiqua erquot quotFullquot quotThirdquurlerquot What is wrong With this picture Model can explain the phases of the Moon The phases of the Moon obieu39s I39mbig occur because light from 39 t a y re ected sunlight As the relative positions of the Earth the Moon and the Sun change we e more or less of the illuminated half ofthe Moon What does the Earth look like from the Full Moon New Moon First Quarter Third Quarter Eventually we want to be able to explain What are 2 observations simple model does not predict What are 2 obsenations simple Eclipses occur only when the Sun and Moon model does not predict are both on the line of nodes 1 Why there are not eclipses every month PlaneafEarth39sorbi Moon sorbit ll u H H plane at he ecliptic around the 2 Why there are annular and total eclipses 5 Line of nodes A ne of Moon s orbit Eclipse can occur Full d Emth No What are 2 obsenations simple 3353 We model does not predict New 1 Why there are not eclipses every month 2 Why there are annular and total eclipses of the sun possible Line of nodes l unumln v Solar eclipses can be either total partial or annular depending on the alignment of the Sun Earth and Moon unnuim mm l rul39ml Eventually we want to be able to explain Lunar eclipses can be either total partial or penumbral depending on the alignment of the un Earth and Moon Eventually we want to be able to explain Question If you were looking at Earth from the side ofthe Moon that faces Earth what would you see during A total lunar eclipse A total solar eclipse The Moon s rotation always keeps the same face toward the Earth due to synchronous rotation wa muld sun all sides nf the Moon and we sea only one has of the Moon Both mm mm m mini m visible To distant constellation A ll Earth39s orbitw r Time and the Moon Two types of months are used in i describing the motion ofthe Moon V th respect to the stars the Moon completes one orbit around the Earth in a sidereal month averaging 2732 days The Moon completes one cycle of phases one orbit around the Earth with respect to the Sun in a synodic month averaging 953 days Question sidereal month averaging 2732 days I O a nal date the M09 IS In the sidereal da 23 W56 min direction of the constellation Gemini y as seen from Earth When will the synodic lunar month averaging 2953 days Moon next be in the direction of solar day 24 hr Gemini 1 One year later 2 3662425 days later 3 One sidereal month later 4 One synodic month later Eventually we Question want to be able to On a certain date the Moon is in the explain direction of the constellation Gemini as seen from Earth When will the Moon next be in the direction of O Gemini 1 One year later 2 3662425 days later 3 One sidereal month later 4 One synodic month later Outline for 07 December Thursday 0 Final Review Exam Preparation Work problems from previous exams Work problems in course notes Final 7 30amelO lsam December l2 Tuesday 7 m oasisquot e in in me canquot 5 at mi cuse xii mini in some Wu are rat his new W auraiaamroorxmi pa About l0 multiple choice questions a Aboutzu gue ions on Chapters lo aw About an guestions that cover material trom Exams lea With about egual coverage or material tor eaeh Exam HOW many questions Will be the same as the ones on prevlous exams Do you rleed to tallte the fll lal e Yuurflrial graue Will be the average otyourhighestthree bereentage seores among Exams lea anu thennal Yuurpercentage seorestor Exams is are summarizeu on a page that is linxeu to on the bottom or the eourse Web page e ltyournnalbereentage seore isthe loWestitWill be uropbeu ltyou missed one examyournnal graue Will be the average o the three exams you tank How was Uranus discovered7 A by a careful search in the 19305 b an astronomer who was conyinced it must be there 5 by accident by an astronomer conducting a sky survey E by an astronomer studying old photographs of the sky several years after they were taken D by careful application ofNewLon s laws to the motion of other planets If Uranus has an orbital period of about 84 years how far does it appear to move across our sky in one year A 023 m a Very small angle because Uranus is a Very long Way away from Earth C 43 D 43 quot The major planet whose spin axis lies almost in its orbital plane is A Neptune B Mercury C Uranus D Mars The tilt ofUmnus s axlswas first deduced from observed orbital motions of its moons rorthe deduction ofthis tilt to be correct itwas necessary to assume that A the moved in the ecliptic plane or at least in the plane ofthe orbit ofUranus the moons passed overbolh north and south poles ofthe planet thereby indicating the planets spin airis the moons were not affected by the gayitational field of the s which would force their orbits to deyiate from the planets equatorial plane D the moons were orbiting in the equatorial plane of Uranus 2 ThearpectedseasonalchangesonUranusbecauseofits 2 Where would the Sun be located in midsummer in the orbital and Spineaxis alignments compared to those on Earth will be n m hemisphere on Uranus as seen by an observer oating above the clouds7 gt the same because the tilt othe spin axis is the same as that ofEath much less because its orbit is circular almost directly over the south pole directly overlatitude 45 to the north othe equator almost directly above the north pole absent because the spin axis is perpendicularto the orbital plane very much exaggerated because the spin axis is almost in almost directly above the equator because it is midsummer the orbitalplane 5 Umnus and Neptune are similarin size and rave similar atmomheres but Neptune is si mn y farther away tom the s thani Uranus byaiatio oraboutznlu What conclusion En bermehed therefure tom the fact that Nepmne s 25 Ifthe orbital period ofUranus is 84 yeaIs and its 39Emf mmre sab mmesam ESU m S S rotational period is about 17 hours how o en will A Nep me samsph m Stcun39a39namm mew h S h n all h nh l 7 yemhuusegzslumaimammmesular energy te unsineve ic yon eno poe 5 MW 2 mmsmm never because ofthe extreme tilt ofthe spin Wm c The sularwmdisablelupenelmleluNeplune s duudetups 5 1 me I m plane and deposit energythere whileUranus srmgnetie eld at once every 42 years de ectsthesolarwind E m Neptuneisbeing distorted Lherefure hating morethan once every 17 hours Umnusbyudal efreets oomJupiterand Samm D once every 84 years Wh h h H l 81 NOT a which othe following characteristics is Uranus e 3 3 m P a 5 5 gene 3 significantly different rom the rest ofthe Jovian energyintemally orvvhoseintemal energy source is l L 7 weak enough thatitis masked by the energy received P ne 5 39umthe Sun 39um evidence ufexcess inoared A Ithas an atmosphere composed primanly of emussmn7 hydrogen and helium A 52mm B Jupiter 0 Neptune D Uranus 1thas aplanetewlde magnetic field It does not have an internal source orheat Ithas a system ofrlngs mu AV Chzmnlu39hits Plum widtenclly Pint139s mtzw39nnper39nd 1 charm mbxtsPlulathce while Plum mmes m The Plumchum systzm mews mwhtch waym us mu martian cl There is m relaumstap belweenxmmanpenad uf Plum and mbxtal penad archaan l charm arms Plum me while Plummlares was Astranamical distances are aften measured in astranamical units parsecs ar lightyears Astronomical Unlt AU 7 One istne average distance between Eartn anu tne Sun E X inE km NW BB rnilliun miles Light Vear IV 7 One lylsthe distance lignt can travel in une year at a s eu u abuut 3 X m5 kms er WEB EIEIEI rniless Parsec pc 7 tne ulstanee atwnien i AU subtends an angle uri aresee urtne ulstanee frum Wnien Eartn Wuulu appear tu be une areseeunu frumthe Sun Question 1 Haw many meters are in a ly The speed af light is 3x10quot8 ms 2 Haw lung dues lt take light ta reach Earth fram the sun 1 AU 15x10quot8 km No e means the samething as 153 on your calculatoror log Thequot is used intext editors and email clients where you can39t create subscripts In powersoften what is a 100 billion divided by 20 million One billion divided by 100 nano Astranamers use angles ta denate the s and apparent sizes af abjects in the s uvel The angular diameter er zngulzrsize ullne Muun l5 er the Mann s l uhtends an angle u v Sidereal Time Prep I What happens to lines as star moves to the right Where will the Sidereal Time Prep I 3110 be pomting 1n 0 What happens to lines as star moves to one Sldereal At 1 the right Lines become more nearly day In one giants parallel solar day at sun an distant star At 2 24 At 2 24 S1dereal T1me sidereal S1dereal T1me sidereal star time hours star time hours since 1 since 1 0 Solar Time quotquot539 0 Solar Time quotquot539 now now sun time At 1 pointing at sun time At 1 1 pointing at line distant line N35 distant POInts star only POIquotts 5quotst star only Which is 3 5 quot we 39 and We 6 longer distant 9020 star 5quot l Sidereal day 2 Solar day 39 u r N 2 At 2 24 S1dereal T1me sidereal Question star time hours since 1 Solar T1me 22339s Ifthe Sun is at your zenith 0n 511 me 11 pointing at June 22 where are you line distant Pfquotnts star only 1 Troplc of Caprlcorn 0 Which is s 2 Troplc of Cancer longer 1 Sidereal day 339 North P016 2 Solar day Q3 4 Equator byN4min What is special about each circle mum mm Antum om a Eanh akwinlersnlnke b Eanh alsummersolxllce What is special about this point On a sheet of paper sketch the moon Eaith and Sun during four different phases of the Moon Color in the dark side of the Moon Eventually we want to be able to explain I What is the phase of the moon when it blocks the sun Parallax 39 Apparent change m I mmquot in an obj eats 39 palm position due to a 39 change in the line of sight In astronomy we us Kepler s Laws I Planet orbit is ellipse I Equal area in equal time I Fanher away planets orbit slower Kepler s Second Law Sun at and funds or animal orbi peyiheliona Aphelion u oulequalarea equalllmelnlervals AloBasfromCloD Question A planet moving in an ellipse with the Sun at one focus will have a speed which is highest when itis farthest it nnthe Sun along the orbit as required by law constant Kepler39s highest when it is closest to the Sun N C to D is lmuch longerdislance 39 e moving faster in CD interval velocity distancelime o 3 n a une locus e ital nrbil Petzhsliuu 6 Question A p anet moving in an ellipse with the Sun at one focus will have a speed which is highest when itis farthest from the Sun constant along the orbit as required by Kepler39s law highest when it is closest to the Sun NEquot Electrons sumo Mr mwu An atom can only absorb special photons The nucleus ofan atom rs surrounded by electrons that occupy on1y certain ororts or energy 1eye1s en an electron Jum s horn one e erg level to another rt ernrts ora sorbs aphoton of appropriate energy and hence ofa speci c wavelength The speetra1 hnes ofa particular e1ernent correspond to the various e1eotron transmons between energy levels in atoms ofthat e1ernent What you see depends on if it is a result of I Absorption light re ected off your face or light re ected by a plant I Emission light from a ame or a heated bar What would this object look like at these three temperatures Principle 1 Light rays from distant object are nearly parallel mum llghl some Enumlllly pnrlllel llghl rays Principle 2 Light re ects offa atmirror in the same wa abasket ball would bounce on the oor angle of incidence i angle ofre ection r Principle 3 Light changes direction when it moves from one mediato another refraction Use Wheel analogy to remember which direction 90 Low Index eg alr The Lines Converge How I remember red bends less The atmosphere scatters blue light mule efteaively than red light hence mostly red tight reaches r eye when you look through hick slits o1 atmosphere at the un 3 Why the e ing Sun looks red How much more energy does a1 cm radius circular collector absorb than a4 cm radius collector nlmm gm 7 me r x 7 Need more info What is special about Ozone Ozone in Earth s Atmosphere thvmuspnu Memsphere stratosphere I What are three modes of eneIgy tmnsfer 7 Convective 7 Conductive iRadiative Outline for 21 November Tuesday Planets and Moons Orbits Surface and Interior Atmosphere Outline for 21 November Tuesday Planets and Moons Orbits Surface and Interior Atmosphere Outline for 21 November Tuesday Planets and Moons Orbits Distance from Sun Eccentricity Distance from controlling object Rotation period Tidal forces Synchronous rotation Ea rth39s orbil Venus at greatest eastern elongation Sun Venus at greatest weslem elongation Mercury at eastern Mercury at greatest western elongation 2001 OrbilofM June13 r r aquot Unlavorabl Mars is at 0 IX May nearapheli Sun r Feb Aug 0 Sept t 39 ac DEX 2005 Novem her 7 Detember 24 Synchronous Rotation Why does it happen Q Chapter 1 1 4b Mercury can be seen most easily from Earth A ear the Sun just alter sunset orjust before sunrise B during a lunar eclipse when the sky is suf ciently dark ne e Moon bec u 39s always close to the Moon 39 r r when the ecliptic plane is high in the sky at night E m 3 D at midnight when it is high in the sky Chapter 1 1 12339 How oft n does a solar trgnsittff ercury ercu assIn Irec across the face of the Slrl lpas see from earth occur A regularly once every synodic period of ercury or every 116 days B never C regularly every sidereal period of Mercury or ever 88 da D relatively infrequently between 10 and 20 imes per century c about h Chapter 13 Zq The length of each of the compared to th a about the same Earth because the tilt of Mars39s spin axis and rotation rate are similarto those of Earth b about twice as long because of Mars39s orbital period Martian seasons h is alf as long as Earth due to the relationship between the Martian period of revolution and its synodic pe 39 Chapter 13 17b Mars experiences similar seasonal changes to those on Earth because A it has about the same shape of elliptical orbit as that of the Earth producing similar changes in solar radiation intensity as the planet orbits B its spin axis is tilted at about the same angle to its orbital plane as is the Earth39s axis 0 the length of its day is very close to an Earth day D the length of its year is very close to that of Earth Key Terms greatest eastern elongation greatest western elongation solar transit prograde rotation retrograde rotation occultation 1to1 spinorbit coupling 3to2 spinorbit coupling Draw ball and arrow at A B C D 0 Mercury s orbital period is 88 days Mercury s rotation period is 58 days Draw ball and arrow at A B C D Mercury s orbital period is 88 days Mercury s rotation period is 58 days Draw ball and arrow at A B C D o D 884 22 days to get to A Mercury s orbital penod is 88 days Mercury s rotation period is 58 days 2258 0375 Draw ball and arrow at A B C D 0375 of a full turn 884 Mercury s orbital period is 88 days Mercury s rotation period is 586 days First rotate move into position in orbit 22 days to get to A 2258 0375 Draw ball and arrow atA B C D c 1125 turns 075 of a full 15 turns mm 0375 ofa turn A 884 22 days to get to A 884 22 days to get to A Ercury s urbital period is 88 days Mercury s urbital period is 88 days Mercury s rutatiun pErlDd is 58 days 2258 0375 Mercury s rutatiun period is 58 days Outline for 21 November Outline for 21 November Tuesday Tuesday Planets and Moons Planets and Moons Orb39ts Sur ce and Interior Core hat surrounds core Rotation period Qu kes Sur ce and Interior Atmosphere Rings Tides Craters Recycling Moon Sulid lithosphe 1 Plastk Inun km aslhznnsphem The surface of Venus shows no evidence of plate tectonics The surface ofVenus is surprisingly at mostly covered with gently rolling hills There are a few major highlands and several large volcanoes The surface ofVenus shows no evidence ofthe motion of large crustal plates which plays a major role in shaping the Earth s surface n a enhquakes m subduclhg plale boundaries New mist forms at midnceill convening mantle l 3 Earth The rusl is cool and rigisi and so an move in large plates New qua is lea d at miduean n 925 e and returned to the inmiorat subduuion zones Extension volcanoes Compression s over upwellmgs and pileup om duwnwellings HD V as Cnnvecting mantle Ia Venusz le rust may he um huland soft to move in plates fhe absence ol water may limis motions ru rigid beneath the c s mm 0 and a mo ram u an somomosssaa axndsn hum lmlanors own In mama39s 10 50 and gamma am lnmrpnutedlnmsrdimlniiryllxki uent Winsome aluminuma i Manama una anan quotm m mmin moans monnamnx Mn healllbenlavhrgnu o 01 am 501312 mamal o zann Zwilhnnamns museum 0 Beanu an MWWSPM39E ailmentamplequot LSIMENIOindsnz lauds Luxomorana A ramblllnllnlm 4 501lluulyissed N150lsullurlltarldl mquot mm mymosa Innis Hamming ma mulewles Disk Dlri aim ulnwinlu milKlan hum msquot 5 my no so m e m lnrkrl an in m l la llama Hzomnz and soZ am Nor msyslml Chapter 12 Bob on both Earth andVenus soine sulfurdioxide is removed from the atmosphereto be locked up in various rocks and minerals 0n arth this 502 is recycled deep beneath the surfaceto be outgassed b volcanoes and again become pan of the atmosphere on Venus this 502 is not recycled Why this r e 5 Venus does not experience the inovein ent of tectonic plates C 0 n Venus tne sulfur dlDdeE rninerals are dissulved by acids in me atmus nere D Because enne nignerternperature en Venustne 502 mlneralsfurmed inere are dl erentfrumtnuse en Eartn and they are essentially permanent and nunrecyclable Chapter 1 2 90h Tectonic activity on Venus differs from tha on Earth in a A active crustal deformation appears to be completely absent B the lithosphere appears to he softer or more plastic and cannot support the creation an rn 39 so i plates C the lithosphere a pears to be cooler and thicker and is there ore too rigid to break up into movin lates D mantle convection appears to be more vigorous and has broken the lithos here into a multitude of small plates instead 0 a few large ones Chapter 14 15q What is believed to be the most important source for the internal heat that Saturn radiates to space a Raindrops of liquid helium bThe original heat offomlation ofthe planet c Decay of radioactive elements in Satum39s large rocky core Chapter 10 71 How do we know the lunar maria or easquot are younger than the lunar highlands aLThe maria have relatively few craters w ereas the highlands are very densely cratered from long exposure to incoming metieoroi s b The maria are still dark whereas the highlands have been lightened by a much longer exposure to radiation from the Sun c The maria are lower in elevation whereas the highlands have had time to be uplifted by tectonic processes Outline for 21 November Tuesday Planets and Moons Orbits Sur ce and Interior Atmosphere Rings Outline for 21 November Tuesday Planets and Moons Atmosphere Life Shield Thickness and gravity Temperature and escape Greenhouse effect Atmospheres gravity and escape velocity Atmospheres gravity and escape velocity e climate on Venus followed a different evolutionary path from that Venus39s high temperature is caused b the greenhouse effect as the dense carbon dioxide atmosphere traps and retains energy from nlight The early atmosphere ofVenus contained substantial amounts of water v This caused a runaway greenhouse effect that evaporated Venus39s oceans and drove carbon dioxide out ofthe rocks and into the atmosphere The climate on Venus followed a different evolutionary path from that Almost all ofthe watervaporwas eventually lost by the action ofultraviolet radiati n on the upper atmosphere The Earth has roughly as much carbon dioxide as Venus but it has been dissolved in the Earth s oceans and chemically bound into its rocks Earth s Atmosphere Mars Atmosphere t in has luwzr a mom erK lempemll u in nJunIIut Chapter 12 12o The temperature in the atmosphere of Venus decreases smoothly with increasing altitude all the wa from the surface hottestxlto the outermost pans e atmosphere coolest hat does this observation tell us aboutthe atmosphere of Venus Hint Think aboutwhy the temperatureinthe Earth39s at os er roll is a Venus has ne uistinet layers at eieuus ur aerusuls in its atrnusphere bVenus has essentially no ozone in its atmosphere e Venus has essentially ne cunVectiun in its atrnusphere Chapter 12 Chapter 12 34b Why is the surface ofVenus hotter than that of 31b At what id the greenhouse effect Mercury even though Mercury is much cioserto the Sun A Chemical reactluns Within the thick eieuus and dense atrnusphere are cuntinuuusly supplying heattu the su ace 3 Cuntinuuus Veieanie aEthltV releases large quantities uf het laVa ente the surface C Venus rutates rapidly therth ensuring that its entire surface is being heated regularly and unifurmly D Thethick 02 atmosphereprevents re niission into space ofthe heat absorbed from sunlight p nt d cease to raise the temperature of Venus A when all the greenhouse gases evaporated B when the radiation from Venus balanced the radiation absorbed by Venus C when the C02 was dissolved in the early Venusian oceans D when the greenhouse gases combined with ls other chemica Key Terms runaway greenhouse effect retrograde rotation dust devi runaway icehouse effect thermal radiation Outline for 21 November Tuesday Planets and Moons Orbits Sur ce and Interior Atmosphere Rings Note I will send out a practice exam today lfyou want me to review certain questions or concepts send me email before Thursday Exam is Tuesday Outline for 17 October Tuesday The Atmosphere Continued From Lecture 13 20 minutes The Magnetosphere 55 minutes Energy Balance Three modes of energy transfer Convective Bulk movement of mass Conductive microscopic jiggling of material but no bulk movement of mass Radiative why you feel colder when it is colder outside in a room that is always 70 degrees Radiation in Radiation out I WWW ms 90 we Y quotmm 314 AWN w sutqr M An 5w mmm w w m I 32 um mm r i m 6 7a SWIM Aimaw w Viimug m mm 194 mm mm m wk The Greenhouse effect Why doesn t radiation get absorbed by greenhouse gasses on the way down Which refrigerator is more energy ef cient Which refrigerator is more energy ef cient Cold airis more Circulation in our atmosphere results from convection and the Earth s rotation Energy exchange is convective Other Convection Energy Exchange Plate tectonics or movement of the plates is driven by convection within the asthenosphere Conductive energy exchange Give an example of conductive energy exchange on Earth Conductive energy exchange Hot core ener yto e s provides in atmosphere is much smaller than that provided by the Sun The greenhouse effect is the A absorption of gases in planeta atmospheric heating B absorption at solar ultraviolet radiation by ry atmospheres leading to of solar infrared radiation bythe mosphere and the subsequent heating ofa planet39s surface C protection ofthe surface of a planet from harmful infrared rays by atmospheric gases D absorption by atmospheric gas infrared radiation emi d n h t g a planet that has be ea ed by solar visible and ultraviolet radiation The greenhouse effect ist e A absorption of solar ultraviolet radiation by gases in planetary a mospheres leading to atmospheric he 39 B absorption of solar infrared radiation bythe atmosphere and the subsequent heating ofa planet39s surface C protection ofthe surface of a planet from harmful infrared rays by atmospheric gases rption by atmospheric ga es of infrared radiation emitted by a planet that eated by solar visible a ultraviolet radi 39 n m a m m aters as seen on the Moon are not apparent on Earth at the present time A the Moon protected Earth from impacts and this resulted in the craters and mari e oon B interplanetary objects have avoided Earth during its his ory C plate tectonics has returned cratered surface layers in o Earth39s interior an weathering has obliterated the more recent D all the potentially damaging interplanetary odies were stopped by Earth39s atmosphe Craters as seen on the Moon are not apparent on Earth at the present time b cause A the Moon protected Earth from impacts and this resulted in the craters and mari B interplanetary objects have avoided Earth during 39 39 ory C plate tectonics has returned cratered su ayers into Earth39s interior weathering has obliterated the more recent craters D all the potentially damaging interplanetary bodies were stopped by Earth39s atmosphe Energy calculattuns tnat stmpty eguate tne lnflux pr sular energy un Eartn thn tne uutfluvv pr energy frum Eartn teag tn a yery lqu ayerage egutttprtum temperature fur Eartn pr arpungez7 c urelB F Wnten ts much luvver tnan tne actual ayerage surface temperature prEartn a c ur48 F Wnatmeenantsm Explalnsthls gtserepaney between tne stmpte pregtettetn DbSENatan7 e A klnEtlE energy at meteurttte matertal tnat ts gtsstpateg tn tne atmpspnere astne parttetes are stpppeg pyrrtettpn e enemteat aettpn between mulecules tn Earth s atmuspnere C tne greenhuuse Effectithe capture by gases tn tne atmpspnere prneatragtattpn thatvvuuld ptnervytse eseape D Extra energ e y cunducted uutvvard frumthe nut tntertetr pr Eartn Energy calculatiuns that Simply eguate the in ux pt sular energy uh Earth With the uut uvv pt eher yfrurn Earth lead tn a very luvv average eguriipriurh temperature tpr Earth at arughg 727 C eth B E Whieh is much luvver PreteCtlve S hlelds thahthe actual average surface temperature ufEarth v tr r a c ur48 F What rheehahisrh expiaihsthis 39 Atmosphere r 0 t g p M th i g 1 g Dibsseerevraaahueny7 e eeh ESimpEprE i run ah Magnetlc eld gt A kinetic energy at meteuritie materiai that is h gissipateg in e atrhpsphere asthe partieies are stpppeg pytrietiph e eherhieai aetiph between muiecuies in Earth s atrhusphere e o the greenhouse effect the capture by gases in the atmosphere orheat radiation thatwould otherwise escape e D extra energy cunducted uutvvard trprhthe hut ihteripr pt Earth Ke Words y The Solar Wind soar wind northern and southern plasma iights magnemsphere XSITSAHSH Radiauon Ions and electrons propagating toward Earth travel time 4 days V Small magne ic field in interplanetary space The Solar Wind The Magnetosphere Charged particles moving in same gquot direction of magnetic eld are not the sular Wind 7 a piasrha traveling at 4mm hrhs de eded When the piasrha gets nearEarth the ehargeg partieies are ihtiueheeg by Earth s ihterhai m rhaghetie tieig gt gt Magnetic field direction The Magnetosphere Charged particles moving perpendicular to magnetic eld are deflected tend to rotate around magnetic eld lines Region ofmagnetic eld o o O 9 O O 9 No magnetic eld The Magnetosphere Electrons rotate in opposite direction es around field Iin No magnetic eld Region ofmagnetic eld b The Magnetosphere lons and electrons moving in opposite direction a current an a current creates a magnetic field Region ofmagnetic eld No magnetic eld Quiz yourself httpwwwspacew eathercenterorgourpr otectiveshied01minigolfhtm Far away from Earth Solar wind distorts dipole magnetic field agnemsphere Formation of the Magnetosphere mm Mmeted ucar Eddhauaururasquish him Outline for 05 September Tuesday I Review topics from Lecture 2 Finish last to ic on the movement of Earth in its orbit special circles 25 minutes I Understanding the movement of objects in the sky with the help ol the celestial sphere 40 minutes I The calendar 10 minutes Eventually We Want to be able to explalrl mls Reminder I Don t be alarmed ifthe material I cover always seems dif cult I spend the most time on the most dif cult concepts in the book I Tutoring 7 see syllabus for times I Group Study 7 some tips I Of ce Hours 7 a er class and by appt Feedback How canl make things easier for you with technology I Post notes before lecture OK 7 On Monday 500 pm you will find Tuesday s notes on Wednesday 50 pm you will find Thursday s notes 7This will result in two sets of lecture notes before lecture and after added annotation I What else I ll pass around a survey on hursday Keywords I Zenith I Projection ri ian I Tropic of Cancer I Tropic of Capricorn I Antarctic Circle I Declin ti I ight ascension Zenith I The direction straight up from an observer Landmarks on the Earth s surface are marked by the Sun s position in the sky throughout the year a 53m amimmamea b mm ilwmmersnlsliu Group Question What is special about each circle mmquot mm 5 m a Earn alwintersolstim b Earth atsummavsolstice Tip Be able to sketch this from memory b Emu mummmoisme 1 Earth atwintersolstim Group Question Sketch image Talk your Way through it Individual Question 0 Where on Earth would you have to be in order to see the Sun at the zenith 1 Equator 2 Tropic of Capricorn 3 Tropic of Cancer Individual Question 0 Where on Earth would you have to be in order to see the Sun at zenith 1 Equator Equinox 2 Tropic of Capricorn 7 winter solstice 3 Tropic of Cancer 7 summer solstice It depends on the time of year Individual Question I Where on Earth would you have to be in order to see the Sun at zenith l Equator Equinox 2 Tropic of Capricorn 7 Dec solstice 3 Tropic of Can 7 une solstice More specific Outline for 05 September Tuesday I Review topics from Lecture 2 Finish last to ic on the movement ol Earth in its orbit special circles I Understanding the movement of objects in the sky with the help ol the celestial sphere I The calendar It is convenient to imagine that the stars are located on a celestial sphere an imagine 0 that has no asisin physical reality I However it is still a model that remains a useful tool of positional as rono I The celestial sphere is b39ect celestial sphere are projections ofthose on the Earth eleslial when m r tial equator divides than into northern and erh hemispheres tial poles are Where arth axis of rotation I tersect tne a sphere is is less than i from the north 9 mm 1 th in the s directly ead an 0 server here on Earth is that observe s equiunx Projection I Connect point on celestial sphere With a he to the center 0 W ere line intersects Earth is Where celestial point projects onto Earth I The North celestial pole projects on to Earth s North pole Tips for getting orientated I First think about What you Will see looking straight up at special points poles and equator I Imagine you are in a dome standing on a sphere and you shoot a paint ball along your line of sight Then the dome rotates What happens to the paint mark When the dome rotates Question Look at a star along zenith at Earth s north pole 2 Moves south 3 Moves north Look at a star along zenith at Earth 2 Moves south 3 Moves north Question 2 Moves e Ica y 3 Moves horizontally Question Look toward horizon at Earth s north pole What happens to the place emailed Slides Question Look toward horizon at Earth s north po What happens to the star durIng the e of a day 1 Stays in the same ace 2 Moves vertically 3 Moves horizontally le Question Look west while you are at Earth s equator you see7 1 Stars moving straight up 2 Stars moving straight down 3 Stars moving horizontally Look west whil you are at Earth s equator What do 7 1 Stars movin stra39ght up 2 Stars movin straight down 3 Stars moVIn horizontally Question e g Q Q Nurth ume pain l 777 rlurialwhn 1 nlrxlialxphlu amr mud c At the equator hilhkoqunbg equator u M H13 north pole 5mm menu Dolo Let s try to explain this Observatory is in Hawaii Which way is a in middle northern latitudes South Which way do stars rotate Why are paths Nurlh nlnhal Pall elnrlil whun 77 half circles v39 Why no starthat yZZiiiax does not move Alternative Visualizations Question Where on Earth would you have to be for your zenith to pass through the celestial equator E 1North Pole mmsz W 2 Tropic of Cancer immamwu Mummy mm 3 Tropic of 12sud3 devmymzuu uemuked Capricorn httpluNMastronomynotescomnakedeye54htmI 4 Equato l39 Question Where on Earth the celestial equatOI 1 North Pole 2 Tropic of Cancer Lu 3 Tropic of Capricorn 4 Equator ination lines of Norl celesllal pole lelenialspher k RA 00 Celestial mum Vemai39 hese will be or overed in Lab We usually draw pictures of how the Earth looks in its orbit around the Sun Sometimes it is convenient to think about the path the sun takes on the celestial sphere throuhout the year Sun s path on the celestial sphere over the course 39 of a day The sun appears in race DUI a Eircu ar Nurlhcelestialpole Edimk Autumnal equinox Summer solstice The eeiipli arm the eiesliai equator intersect at uriiy twu puirils Eah puiril is eaiieu an equinox The puiril uri the eeiipti rarmesl riurm at me riurmerri hemisphere is eaiieu the summer solsuce Winter solslice 39 Celestial equator South celeslial pale Vernal equinox Path of Sun on Celestial Sphere The path that the Sun or any star takes over a day is called a diurnal circle Diurnal circles are parallel to the celestial equator On the day of an equinox the path of the Sun is same as the celestial equator Meridian Trace meridian in sky by lying on your back with your head pointing north Draw a line with a laser pointer in the sky that connects north to your zenith to south Local noon is de ned to be when the Sun crosses the upper meridian which is the half of the meridian above the horizon Horizon Outline for 05 September Tuesday Review topics from Lecture 2 Finish last topic on the movement ol Earth in its orbit special circles Understanding the movement of objects in the sky with the help ofthe celestial sphere The calendar sections 27 28 ol text Positional astronomy plays an important role in keeping track of time Apparent solar time is based on the rent motion of the Sun across the celestial sphere which varies over the course of the year Mean solar time is based on the motion 0 an imaginary mean sun along the celestial equator which produces a uniform mean solar day of 24 hours Ordinary watches and clocks measure ime Sidereal time is based on the apparent motion of the celestial sphere The Moon helps to cause precession a slow conical motion of Earth s axis of rotation Ei h sixisu minquot hingesdlm n lFVEltliilD l x mm rotation Gravitational pull of mg Sun Precession causes the gradual change of the star that marks the North Celestial Pole m mm dullIva 0mm mm was muon Astronomical observations led to the development of the modern calendar The clay is based on the Earth s rotation The year is based on the Earth s orbit The month is based on the lunar cycle The time for each cycle is not exactly integer or constant so astronomers use the average or mean clay and leap years to keep the calendar and time consistent Freedman Universe 7e Ch 01 10f6 7e Ch 01 Freedman Universe 7e Ch 01 Cha pter 1 Introduction 1 The quality that perhaps above all others makes human beings stand out among all the animals 395 39 the lack of animosity toward other human bein s 39 the driving curiosity and desire to explore their surroundings and understand them 7 the overwhelming desire for selfpreservation Section 11 2 After making makes a series of observations of a certain phenomenon in a laboratory a scientist develops a theory that explains these results and predicts new values for future observations Another scientist makes a series of appropriate observations but his results always contradict the predictions of the theory Whats ould the first scientis o 39 Attempt to modify his theon to bring it into accord with the new observations and if he cannot do so discard his theory Discard the theory immediately Ignore the new results because his theory explains the earlier results satisfactorily Section 11 3 Which of the following fundamental requirements must be met in order that a theory or idea can be considered a scientific theory quot It has to explain all known observations 39 It has to be based upon mathematics The theory should predict new observations even if they prove the theory wrong Section 11 4 Which of the following statements best represents the overall rationale for scientific investigation V Reality is comprehensible and a limited number of fundamental principles govern the nature and behavior of the universe 7 The universe is a hodgepodge of unrelated things behaving in unpredictable ways Nevertheless we must continue to observe it in case this behavior threatens the Earth An example o such an observation might bet e detection of an asteroid bearing down upon Earth 39 The behavior of the whole universe is governed by man39s observations of it in such a way as to hide the fundamental truth Figure 11 9182006 520 PM 2of6 5 The Hubble Space Telescope HST represents a very significant advance in astronomy because 39 it operates above the Earth39s absorbing and distorting atmosphere 2quot its large orbit gives it views of objects from different viewpoints thereby providing measurements of distances to nearby stars e s apes an sizes of planets etc quot it is closer to the objects that it observes making it capable of seeing things more clearly and in more detail than observatories upon Earth Section 12 5 What is a solar system 7 A collection of planets and other smaller objects orbiting around a star eg the Sun A collection of a million to a hundred billion or more suns stars in a large system often containing spiral arms for example our own Milky Way Galaxy 7 A collection of two or a few suns stars orbiting around each other Figure 12 7 In our solar system which of the following statements is true 7 The diameter ofJupiter is smaller than that of Saturn and of its rings 79 The diameter ofJupiter is larger than that of Saturn and of its rings The diameter ofJupiter is larger than that of Saturn but smaller than the diameter of Saturn39s rings Section 13 8 When did the idea of thermonuclear fusion as source of energy first develop and in what context C During World War II in theoretical studies of nuclear explosives In the late nineteenth century during experimental studies of radioactivity 39 In the early twentieth century during theoretical studies of the interiors of stars Section 14 some of the characteristics of quasars that make them so mysterious They involve a spectacular detonation with the complete or almost complete destruction of a star and the ejection of enormous amoun s o gas in o space Th e among the most distant objects in the universe and outshine normal galaxies by a factor of a hun red 7 They appear to be dead stars and we receive energy from them only in brief highly repetitive bursts 9 Quasars are among the most exotic of all of the objects that astronomers study What are 7 9182006 520 PM Freedman Universe 7e Ch 01 3of6 7e Ch 01 Box 11 10 In a particular total solar eclipse the Moon was observed from a location upon Earth to cover the Sun exactly that is the Moon39s angular size was the same as that of the Sun at that time If the Sun is 15 x 10 km away and has a diameter of 14 x 106 km how far away is the Moon if its diameter is 35 x 103 km 327 x 101km Section 15 11 Stars on the equator appear to move through a full 350 degrees in about 1 day because of the Earth39s rotation How fast are they moving in degrees per minute 7 4 degrees per minute i 15 degrees per minute 14 degree per minute Box 11 Section 15 12 An average observatory telescope can resolve objects that subtend about 1 arc second What would be the angular size of a 2metertall astronaut as seen from this observatory if she were involved in extravehicular activity and sunlit outside the International Space Station as it passed overhead in its orbit 400 km above the Earth Would you e able to see her on the Space Station V 39 arc seconds Yes you should be able to see the astronaut very easily 103 arc second Yes you would JUST be able to make out this astronaut 103 x 10 3 arc second You would NOT be able to see the astronaut Section 15 13 The human eye can just separate two bright lights when they are 1 arc minute apart in angle dime faceon at a distance of 720 meters will have an angular diameter of 5 arc seconds If a line of dimes is placed 720 meters away how many would fit between 2 lights that appear to be 1 arc minute apart 39 12 720 39 112 or 0083 a small fraction of 1 dime Section 15 Box 11 14 The Crab Nebula shown in Fig 16 Freedman amp Kaufmann Universe 7th Ed has a diameter of about 10 ly and is at a distance of 5500 ly What angle will this supernova remnant subtend in 9182006 520 PM 4of6 V 53 arc minutes 650 arc seconds 39 16 x 10 3 arc seconds Section 16 22 x 108 km Section 16 15 The wavelength of red light is about 0000 000 65 m What is this wavelength in scientific nota ion 55 x 10 8m 55x 10 7 m T 55x1o 6m Section 16 17 Astronomers sometimes observe objects in the sky at an infrared wavelength of 44 x 10 6 m What is the wavelength expressed as a decimal fraction 39 0000 004 4 m 0000 000 44 m 0000 044 m Section 17 18 Astronomers use units such as lightyears for distance which are not included in the International System of Units that is used by the rest of the scientific community because quot astronomy is the oldest science and astronomers continue to use units that were developed before the present standar sys em was evised 39j astronomers require special units in order to account for such concepts as the curvature of space the existence of black holes and the constancy of the speed of light within the framework of the un39verse 39 distances are so vast in the observable universe that alternative and larger units are more convenient for use in astronomy Section 17 9182006 520 PM Freedman Universe 7e Ch 01 50f6 7e Ch 01 19 What is a parsec 39 A unit of distance used in astronomy the distance from which 1AU subtends an angle of 1 arc second 39 A unit of angle used in astronomy the angle subtended by 1AU at a distance of 1 lightyear 39 A unit of time used in astronomy the time taken for light to travel from the Sun to the Earth Section 17 20 A new asteroid is discovered at a distance of 33 AU from the Sun What is this distance in kilometers 221 x 108 km 491 x 108 km 330 x 108 km Section 17 21 What is the definition of the parsec V The distance through which light travels in one year 7 The distance at which 2 AU the diameter of the Earth39s orbit subtends exactly one second of c ar V The distance at which 1 AU the radius of the Earth39s orbit subtends an angle of exactly one second of arc Section 17 22 In which of the following sequences are the distances in the correct order of increasing size 39 108 km 1 AU 0001 Iy 1 pc 1 AU 108 km 0001 ly 1 pc 39 108 km 1 AU 1 pc 0001 ly Section 17 23 Suppose that a particular star were 15 lightyears ly away from the Earth What would this dista nce be in parsecs pc pc 0217 pc Section 17 24 Suppose that a particular cluster of stars were 427 kiloparsecs kpc away from the Earth What would this distance be in lightyears ly 9182006 520 PM 60f6 1310Iy 139 ly 13920 ly Submit Reset Question Mark Perception licensed to Bedford Freeman amp Worth Publishing Group LLC 9182006 520 PM Freedman Universe 7e Ch 02 10f7 Freedman Universe 7e Ch 02 Sections 23 and 24 1 One feature of the sky that was most probably used by ancient people to define directions and thereby navigate safely across oceans was the fact tha 39 the Sun rose and set at the same points on the horizon day by day 39 the Moon rose and set at the same points on the horizon night by night 39 certain stars rose and set at the same points on the horizon night by night Section 21 2 Which of the following positions in the sky was most probably used by ancient people in the orthern Hemisphere in the definition of a calendar and determination of certain key times in their year 7 The date when the brightest planets rise andor set at their most northerly points on the horizon 39 The date when sunrise occurred at its most northerly point on the horizon The date on which the Moon rose at its most northerly point on the horizon Section 22 3 What are constellations 7 Occa 39 s when planets pass close to each other as seen from the Earth as the planets follow their separate orbits aroun t e Sun 7 Groupings of stars that cover various areas of sky from large to small 39 Galaxies made up of billions of stars orbiting around a common center Section 23 er west in longitude if observed at precisely e same absolute time Universal Coordinated Time or UTC which will be 10 PM Montana local time 39 In the western sky 39 Overhead of course 7 In the eastern sky Section 24 5 The celestial sphere is 7 an ancient Greek name for the Sun 9182006 523 PM Zof7 7e Ch 02 a large imaginary sphere centered on the Earth on which all objects in the night sky appear to be located 7 he large band of constellations centered on the Earth through which the Sun appears to move each year Section 24 and Box 21 5 If the Sun39s declination is 0 on March 21 of a particular year how long will it be before it is at this declination again 1 year later Section 24 and Box 21 7 If the Sun39s declination is 2350 on June 21 of a particular year when will it next be this declination V 5 months later 3 months later C year later Section 24 8 If one stands on the equator are there any stars that always remain above the horizon that is are circumpolar 7 It depends upon the time of the year or the season This is because the Earth39s axis tilts at different angles to the equator at different times of the year making some stars circumpolar at certain times oft e year C Of course All stars would be visible for 24 hours from this location if it were not for daylight No From this position all stars cross the horizon at some time rising and setting at intervals of 12 hours Section 25 9 The primary cause of the seasons on the Earth spring summer fall and winter is that the Earth39s axis of rotation tilts in a constant direction relative to the Earth39s orbital plane The motion of the Eart aroun he Sun then changes the angle of incidence of solar radiation at each point on the Earth39s surface through the year C the tilt angle of the Earth39s axis of rotation changes relative to the Earth39s orbital plane Spring and fall occur w en the axis of rotation is perpendicular to the orbital plane and summer and fall when the axis is tilted toward an away rom t e Sun respectively 7 the distance between the Sun and Earth varies because of the elliptical orbit of the Earth Summer occurs when the Earth is closest to the Sun and winter when the Earth is farthest from 9182006 523 PM Freedman Universe 7e Ch 02 3of7 Section 25 10 To an astronomer the vernal equinox is the point on the celestial sphere where the Sun crosses the ecliptic moving north 39 the beginning of autumn in the northern hemisphere the point on the celestial sphere where the Sun crosses the celestial equator moving north Section 25 11 You are standing somewhere on Earth on a bright sunny day when you notice that a tall vertical telephone pole has no shadow From that observation by itself what do you know about where you might be standing 7 Exactly at the North or South Pole in midsummer 24hour daylight Anywhere between the Tropic of Cancer and the Tropic of Capricorn V Exactly on the equator Section 25 and Box 21 12 The declination of the Sun on the first day of spring is 139 00 2350 north variable depending on the year Section 25 13 During one full year the ecliptic plane ie the plane of the Earth39s orbit around the Sun 39 is coincident with the celestial equator by definition 39 varies between 235 and 235 to the celestial equator making an angle of 0 to the equator at midsummer and midwinter 39 remains fixed at an angle of 2350 to the celestial equator Section 25 14 The Earth is closest to the Sun during winter in the southern hemisphere 7 uring summer in the southern hemisphere when the Sun is directly overhead at the equator Section 25 15 It is warmer in summer than in winter because 9182006 523 PM 4of7 7e Ch 02 V the Sun is higher in the sky and the days are longer the Earth is closer to the Sun the Sun is lower in the sky and sunlight passes through a longer path in the atmosphere thereby heating it more in summer Section 26 15 The Earth39s rotation axis is tilted relative to the Earth39s orbital plane and the direction of this tilt wobbles or precesses cyclically with a period of 39V one year causing the seasons spring summer autumn and winter 24 ours causing the sun to appear to rise cross the celestial meridian and set once each ay 26000 years causing the vernal equinox to change position along the celestial equator Section 26 17 The cause of the Earth39s slow precession is the effect of the gravitational forces from the Sun andt e oon on the Earth39s north and south poles which are at different distances from the Sun or the Moon due to the tilt of the Earth39s axis of rotation 71 on the equatorial bulge of the rotating Ear h t on the Earth as a whole as if all of the forces were applied at the center of the Earth Box 21 18 In astronomy what does the term Right Ascension mean The length of time since the object crossed the celestial meridian The position of an astronomical object on the celestial sphere as measured by lines perpendicular to the celestial equator similar to lines of longitude on the Earth Ci Th osition of an astronomical object on the celestial sphere as measured by lines parallel to the celestial equator similar to lines of latitude on the Earth Section 26 19 The Right Ascension of the Sun on the first day of spring is hr slowly changing from year to year because of the precession of the Earth39s rotation axis hr 0 Section 26 and Box 21 20 What is the angle measured in degrees between two stars one at Right Ascension 439 9182006 523 PM Freedman Universe 7e Ch 02 50f7 declination 0 and the other at Right Ascension 639 declination 0 i39 20 39 300 Section 26 21 As the Moon orbits around the Earth its path on the celestial sphere is very close to the celestial equator 39 is very close to the path followed by the Sun the ecliptic is very close to a line of right ascension passing close to each celestial pole once each orbit Section 27 22 The Sun is not a good timekeeper and two of the following statements correctly give reasons for this Which of these statements is NOT a correct reason 39 The Earth39s equator is tilted relative to the Earth39s orbital plane The Earth39s orbit is elliptical causing the Earth39s orbital speed to vary with time during the ear 7 The Earth39s rate of rotation which determines the length of the day varies with time Box 22 23 How long does it take the Earth to rotate once around its axis compared to the distant stars 7 23 hours 56 minutes and 4 seconds measured in Coordinated Universal Time 39 Exactly 24 hours measured in Coordinated Universal Time by definition 365 14 days Section 27 24 Suppose that on a particular night the star Spica in the constellation Virgo rises at exactly 1030 pm mean solar time At what time will it rise one night later 39 1034 PM 1025 PM 1030 PM Section 27 25 The meridian or celestial meridian 39 passes directly overhead exactly once is always directly overhead for ea observer39s position on the Earth each day for any given observer on the Earth ch observer regardless of the time of day or night or the 9182006 523 PM 60f7 7e Ch 02 passes directly overhead only for observers on the line of longitude that passes through Greenwich England Box 22 26 The difference between 1 second of sidereal time and 1 second of mean solar time is V a very small but variable interval of time because of the variable motion of the Earth in its orbit a very small but finite and fixed interval of time 39V zero because they are defined as equal Section 28 27 What is a tropical year V The time for the Earth to orbit around the Sun exactly once relative to the stars The time from January 1 to the next January 1 measured at midnight at the start of each January 1 and therefore variable because of leap quota The time from the start of one spring the Sun precisely on the celestial equator moving north to the start of the next spring Section 28 28 If we were to measure the Sun39s position in the sky very carefully we might notice that the center of the Sun gradually shifts along the ecliptic being exactly in line with a particular star at some point in time How long will it be until the center of the Sun is exactly in line with this star ain One calendar year 39 One tropical year One sidereal year Section 28 29 Leap years which contain one extra day are needed in order to correct for the fact that the length of the day has changed since the calendar was devised by ancient Greeks because of the effect of the tides in slowing down the spin of the Earth the Earth speeds up and slows down as it orbits around the Sun 1 year is about 36525 days long instead of exactly 365 days Submit Reset 9182006 523 PM Freedman Universe 7e Ch 03 10f5 7e Ch 03 Freedman Universe 7e Ch 03 Section 31 1 The Moon shows different phases because 7 it rotates slowly to reveal more or less of its illuminated hemisphere while remaining relatively fixed against the celestial sphere of stars 39 it moves slowly in and out of the Earth39s shadow in its orbital motion around the Earth 7 we view the sunlit hemisphere of the Moon from different angles as the Moon orbits the Earth Section 31 2 At what time in its monthly cycle will the Moon be seen high in the sky in the daytime from midlatitudes 39 Only when it is full Quarter Moon 7 The Moon is never visible in the daytime Section 31 3 On a particular day the Moon appears more than half illuminated and on the following night it appears closer to being halfilluminated What is the phase of the Moon 39 Waning gibbous Section 31 4 When does the new Moon rise approximately 7 At midnight At sunset 7 Close to sunrise Section 31 5 Where in the sky will the full Moon appear at sunset in the northern hemisphere C High in the southern sky Low in the eastern sky Low in the western sky Section 32 9182006 525 PM Zof5 5 If you were an astronaut on the Moon in what position close to the Moon39s equator would you have to stand in or er to be in perpetual darkness 7 On the side of the Moon that faces away from the Sun You cannot do this There is nowhere near to the Moon39s equator where you can be in perpetual darkness 7 On the side of the Moon that faces away from the Earth Section 32 7 Which of the following correctly describes the rotation of the Moon 7 The Moon rotates once per year in order to keep one face pointed toward the Sun a necessary condition for us to see the Moon phases every month C The Moon rotates once per month to keep one face always toward the Earth The Moon does not rotate at all around an axis because it always keeps one face toward the Earth Section 32 8 As the Moon orbits the Earth and we observe its phases how fast does the terminator the dividing line between illuminated and dark parts of the Moon move across the lunar surface in terms o angle of lunar longitu e j The terminator will never move because the Moon does not rotate with respect to the Earth 7 360 degrees in about 1 year or about 1 degree per day 360 degrees in about 1 month or about 12 degrees per day Section 32 9 Synchronous rotation of the Moon refers to the fact that the Moon rotates once upon its axis every lunar cycle or every revolution around the Earth otates once upon its axis every year or every revolution of the EarthMoon system around t e Sun C never rotates with respect to the distant stars Section 32 10 What is the difference between a sidereal month and a synodic month A sidereal month is one rotation of the Moon with respect to the stars whereas a synodic month is one rotation of the Moon with respect to the Sun 7 A si erea month is the actual rotation period of the Moon whereas a synodic month is 112 of the length of a standard tropical year A sidereal month is the period of rotation of the Moon as we actually see it ie an quotastronomicalquot mont whereas o ic month is an average or quotmeanquot month used to determine the dates of certain religious events 9182006 525 PM Freedman Universe 7e Ch 03 3of5 Section 32 11 How long will a full lunar quotdayquot last from midday to midday at any location on the Moon39s equator 39 Infinite The Sun will not appear to move in the sky or rise and set because the Moon does not rotate 39 273 days the actual period of rotation of the Moon on its axis 7 About 295 days because the Moon rotates once per orbit around the Earth Section 32 12 If you were camped on the Moon how long would you be in daylight from sunrise to sunset during one lunar quotdayquot 39 About 12 hours because the Moon rotates at the same rate as the Earth About 14 days 7 were in daylight then you would ALWAYS be in daylight because the Moon does not rotate with respect to the Sun Section 32 13 Astronauts have a great view of Earth as they land at a lunar base near the equator How often will they see the Earth move over their lunar horizon during their stay on the Moon The Earth will move slowly across their sky completing an orbit in 1 39 The Earth will move across their sky with a period of about 1 month the rotation period of the Moon 7 The Earth will remain stationary in their sky and therefore it will never cross their horizon Section 32 14 Astronauts at a lunar base near the crater Copernicus note that the Sun is high in their sky on March 1 2020 When will it next reach this high position in their sky 7 The Sun will remain fixed at this position in the lunar sky because the Moon does not rotate with respect to the Sun 7 March 27 2020 or 273 days after March 1 39 March 29 2020 or 295 days after March 1 Section 33 15 The plane of the ecliptic is a flat plane containing the Earth39s orbit 7 a flat plane defined by the intersection of the Earth39s orbit and the Moon39s orbit a flat plane containing the Moon39s orbit 9182006 525 PM 4of5 7e Ch 03 Section 33 15 The reason eclipses do not occur at every new Moon and every full Moon is that Iquot the Moon39s orbit is inclined at an angle to the Earth39s orbit 393 the Earth39s equator is inclined at an angle to the Earth39s orbit the Moon39s orbit is inclined at an angle to the Earth39s equator Section 33 17 During a particular eclipse you find that the Sun is blotted out because the Moon comes e Sun This is an example of a solar eclipse 39 a penumbral eclipse Section 34 18 Lunar eclipses occur V about twice per year when the Moon goes into the shadow of the Earth every month when the Moon moves into the Earth39s shadow to produce the dark New Moon about twice per year when a specific part of the Earth is within the shadow of the Moon Section 34 19 Which of the following statements is true 7 l eclipse occurs only at full Moon phase and can be seen from anywhere on the nighttime hemisphere o 39 A lunar eclipse occurs only at full Moon and can be seen from within a narrow strip on the Earth39s surface 39 lunar eclipse occurs only at new Moon and can be seen from anywhere on the nighttime hemisphere of Earth Section 34 20 In the picture of a lunar eclipse in Figure 39 of Freedman and Kaufmann Universe 7th Ed why is the fully eclipsed Moon reddish in color compared to the partly eclipsed Moon C t e true reddish color of the Moon 5 o 5 up only under this low level of illumination the sunlight being bright enough at all other times to make the Moon appear white Because the only sunlight that reaches the Moon at this time has passed through the Earth39s atmosphere and this sunlight is re ened because the b ue component as been scattered from it Because the Moon becomes much colder during a total eclipse and the surface glows with a cooler light at this time 9182006 525 PM Freedman Universe 7e Ch 03 50f5 Section 35 which no part of the solar disk is visIbe 39 Very small with a typical diameter less than about 270 km Very large extending over the whole sunlit Earth such that everyone on this side of Earth sees an eci se 7 About as large as the Moon with a diameter of about 3500 km 21 During a typical total solar eclipse how big is the shadow of the Moon upon the Earth from Section 35 22 Why are some solar eclipses annular with all but an annular ring of the Sun obscured rather than total the whoe Sun obscured 39 The Moon39s orbit is elliptical and occasionally the Moon is too far away for the umbra of its shadow to reach the Earth39s surface quot The Earth is sometimes farther away from the Sun such that the Moon39s angular diameter is less than that of the Sun at this time 7 The Moon39s shadow passes just north or south of Earth causing only an annular ring eclipse Section 36 Box 32 23 An quoteclipse yearquot is V t e time between two successive alignments of the Sun the Moon and line of nodes 39 the time between two solar eclipses observed from the same location on the Earth he time from when the line of nodes points toward the Sun to the time when the next identical alignment occurs Section 36 24 Who was the first person in history to measure the size of the Earth 7 The Italian astronomer Galileo quot The Polish astronomer Copernicus 39 The ancient Greek astronomer Eratosthenes Submit I Reset I Quesu39on Mark Percepu39on licensed to Bedford Freeman amp Worth Publishing Group LLC 9182006 525 PM Freedman Universe 7e Ch 04 10f9 Freedman Universe 7e Ch 04 Section 41 1 Which of the following concepts of the universe did the ancient Greek philosophers believe was correct 39 Suncentered with the Earth Moon planets and stars orbiting around a stationary Sun quot Stationary with the Sun Moon planets and stars fixed in position but appearing to move when viewed from a rotating Eart Earthcentered with the Sun Moon planets and stars orbiting around a stationary Earth Section 41 and Figure 42 2 As observed from Earth the motion of a planet known as direct motion refers to 39 a slow westward motion against the background stars the motion directly toward the Earth at certain points of the planet39s orbit 7 a slow eastward motion against the background stars Section 41 3 Of the following planets which was known in Greek times 39 Uranus Mercury 7 Neptune Section 41 4 The very successful Ptolemaic model to describe and predict the apparent motions of the planets a su 39 m to orbit the Earth had the planets moving 7 in ellipses with their respective foci at the center of Earth in circles around the Earth the planes of which were precessing slowly around a direction perpendicular to the ecliptic plane 7 in l circles the centers of which were moving around the Earth more slowly in larger circles Section 41 5 In the Greek model of planetary motion a planet follows a small epicyclic motion as it moves around a circle while the center of this circ e moves on a larger circle the deferent In what position is it when it appears to be in retrograde motion The planet is exactly on the deferent and is moving for a short while directly toward the Eart The planet is farthest from the Earth 9182006 527 PM Zof9 7e Ch 04 V The planet is closest to the Earth Section 42 5 Who was the first person to propose that the Earth and all other planets orbit the Sun A sixteenthcentury Polish astronomer named Copernicus An ancient Greek astronomer named Aristarch aquot A seventeenthcentury German astronomer named Kepler Section 42 and Figure 45 7 In the modern heliocentric model of the solar system the retrograde or quotbackwardquot westerly motion of a planet against the background stars is a consequence of 393 our view of the planet from a rotating object the Earth our view of a Sunorbiting object from a constantly moving viewpoint the orbiting Earth 39 the speedup and slowdown of the planet as it moves in an elliptical orbit around the Sun Section 42 and Figure 46 8 What condition describes the position of greatest elongation for an inferior planet in our solar system The angle between the EarthSun line and the planetSun line is 90 39 The angle between the EarthSun line and the Earthplanet line is 90 L The angle between the Earthplanet line and the planetSun line is 90 Section 42 and Figure 46 9 When a planet is at conjunction it will be at the farthest position from the Sun in the sky as seen from the Earth set at the same time as the Sun 39 rise as the Sun is setting Section 42 and Figure 46 10 When a planet is at superior conjunction 397 the Sun is between t e Earth and the planet the Earth is between the Sun and the planet 393 the planet is between the Earth and the Sun Section 42 9182006 527 PM Freedman Universe 7e Ch 04 3of9 7e Ch 04 11 Which one of the following objects passes through positions of greatest elongation as seen from the Earth The Moon Section 42 12 At which position will Jupiter be seen at its highest in our sky at midnight 39 Opposition Greatest elongation 39 Conjunction Section 42 13 Suppose that on some particular day the straight line from the Sun to the Earth continues on to pass through Mars and ultimately through some particular star in the sky One synodic period later Mars w39 quot lined up again with the Earth and the star but not with the Sun 39 lined up again with the Earth and the Sun but not with the star lined up again with the star and the Sun but not with the Earth Section 42 and Box 41 14 The synodic period for a planet is different from its sidereal period because quot the planet39s speed varies as it moves around the Sun in its or i the planet39s orbital distance from the Sun is different from that of Earth from the Sun 7 the Earth and hence the observer moves Section 42 and Box 41 15 A space probe is placed in a circular orbit around the Sun orbiting the Sun once every 10 months Use one of the equations 39n Box 41 of Universe man and Kaufmann 7th Ed to calculate how often the probe passes between the Earth and the Sun 7 Once every 02 years 2 12 months 39 Once every 045 years 5 12 months Once every 5 years Section 43 16 Tycho Brahe39s major contribution to the development of modern astronomy was 39 a detailed and successful Earthbased model of the solar system 39 the detailed and precise measurement of the positions of stars and planets in our sky 9182006 527 PM 4of9 the first telescope observations of the variation of apparent shapes and sizes of planets particularly Venus and Mercury Section 44 17 The shape of the Earth39s orbit around the Sun is V elliptical with the Sun at a point known as a focus of the ellipse 39 circular as are the orbits of all other planets around the Sun elliptical with the Sun at the center of the ellipse Section 44 18 Which of the following methods could one use to demonstrate that the Earth39s distance from the Sun varies as a consequence of its elliptical orbit 39 Measure the time between successive passages of a given star through your zenith Measure the variation in the length of the shadow of a vertical pole produced by the Sun at midday throughout the yea r 392 Measure the angular size of the Sun during the year Section 44 19 An object orbiting the Sun with an orbital eccentricity of 01 has an orbit whose shape is 39V slightly elliptical but almost circular 39 a ong narrow ellipse circular but with the Sun offcenter in the circle Section 44 20 A planet moving in an ellipse with the Sun at one focus will have a speed which is 7 highest when it is farthest from the Sun constant along the orbit as required by Kepler39s law highest when it is closest to the Sun Section 44 and Figure 411 21 If you were to draw a straight line from the Sun to Mars and then watch this line as Mars moves along its orbit aroun what would you see C The angle measured in degrees swept out by the line in one week would be the same in all parts of Mars39s orbit 39 The length of the line measured in kilometers would be the same in all parts of Mars39s orbit 7 The area swept out by the line in one week would be the same in all parts of Mars39s orbit 9182006 527 PM Freedman Universe 7e Ch 04 50f9 7e Ch 04 Section 44 22 Kepler39s laws 7 apply only to large planets orbiting our Sun but provide only an approximate description for smaller objects such as asteroids etc and are not applicable at all for other situations such as mutually orbiting binary s ars apply for all objects orbiting the Sun such as planets comets asteroids and manmade space probes but do not hold for objects orbiting any other object in the universe 7 can be shown to apply universally whenever two objects orbit each other under gravitational attraction Section 44 and Box 42 23 A solar observatory has been put into space orbiting the Sun in a circular orbit once every 10 months Use one of the equations in Box 42 o Universe Free man an Kaufmann 7t calculate how far the satellite is from the Sun ie the radius of the satellite39s orbit 0833 AU 39 0594 AU Section 44 24 According to Kepler39s third law an asteroid orbiting the Sun in a circular orbit at twice the Earth39s distance rom the Sun would have a sidereal period of 39 80 years Section 45 25 Who was the first person to prove through direct astronomical observations that planets ed moved aroun the Sun rather than around the Earth as the ancient Greeks believ Kepler Section 45 26 Which of the quotphasesquot of Venus first seen by Galileo with his telescope equivalent to those of t e Moon convinced him that Venus orbited the Sun rather than the Earth 7 New Moon or dark phase 39 Gibbous phase Crescent phase 9182006 527 PM 60f9 Section 45 27 Galileo observed four moons orbiting Jupiter In which way did this observation contradict eek dogma about the universe to incur the wrath of the established church which believed and taught the Greek idea quot This observation showed that there were objects that did NOT orbit the Earth contrary to the Greek model 7 This observation showed that there were objects that did not orbit the Sun as required by the Greek model aquot This observation showed that planets other than the Earth had a moon or moons contrary to Greek belief Section 46 28 Newton39s first law of motion that quota body remains at rest or moves in a straight line at a constant speed unless acted upon by a net outside forcequot appears to be contradicted by everyday experience Why ist is quot The force of friction almost always acts on any moving object on the Earth supplying an unbalanced force that slows the object down 39 Gravity always acts on objects on the Earth supplying an outofbalance force that slows down any object moving across t e Earth39s sur ace 39 h rotates and this rotational motion significantly affects the motion of objects across the surface of the Earth Section 46 29 A dog team is pulling a sled northward over the snow at a constant speed Which one of the following statements aboutt e net force on the sled is correct 39 The net force on the sled is directed forward through the dogs quot The net force on the sled is zero 39 39 Th n force on the sled is directed at an angle downward ahead of the sled being made up of a forward force by the dogs plus a downward force by gravity Section 46 30 What is acceleration The change in an object39s velocity in one second The change in an object39s position in one second quot1 The total force on an object Section 46 31 Which of the following objects is NOT accelerating 39 39 A person standing on scales weighing hImsef The Moon moving around in its orbit 9182006 527 PM Freedman Universe 7e Ch 04 7of9 7e Ch 04 39 An apple falling toward the ground in the Earth39s gravitational field Section 46 32 Which of the following three objects or persons is NOT accelerating 39 A water skier slowing down while moving in a straight line after letting go of the tow line quot A skydiver falling in a straight line at a constant speed ie at quotterminal speedquot 39 A racecar traveling at constant speed around a circular track Section 46 33 An astronaut exerts a certain force on a satellite to accelerate it away from the Space Shuttle She then exerts the SAME force on another satellite that has twice the mass of the first satellite How oes the acceleration of the second more massive satellite compare to that of the first satellite quot The two satellites have exactly the same acceleration because the forces are the same 39 The more massive satellite has half the acceleration of the lighter satellite The more massive satellite has twice the acceleration of the lighter satellite Section 46 34 A person is pushing and slightly squashing a basketball against a wall According to Newton39s Third Law the reaction force ort e orce that the hand exerts on the basketball is V the force that the basketball exerts on the wall the force that the wall exerts on the basketball the force that the basketball exerts on the hand Section 46 35 A moose is standing at rest upon a rock The weight of the moose is the force of gravity pulling downward on the moose and the rock is pushing up on the moose with a force that is equal and opposite to this weight This is an example of 39 Newton39s third la None of Newton39s laws Newton39s second law Section 47 36 In which of the following situations is the gravitational force from the Earth on 1 kg of matter equal to zero 7 1 kg of matter at the center of Earth A 1 kg mass orbiting in the Space Shuttle 39 A 1 kg mass at rest on a smooth surface of ice on Earth 9182006 527 PM 80f9 Section 47 37 If a comet approaches and then recedes from the Sun in a parabolic orbit it will 7 return toward the Sun after anything from a few years to millions of years or even never depending on the size o t e orbit V return toward the Sun only after several thousand years 7 never again return toward the Sun Section 47 38 Which of the following masses would feel the greatest gravitational force from the Earth 7 450 kg at a distance of 3 Earth radii from the Earth39s surface or 4 radii 25400 km from its center V 150 kg on the surface of Earth 5400 km from its center 39 300 kg at a distance of 1 Earth radius above the Earth39s surface or 2 radii 12800 km from the center of the Earth Section 47 39 If there is a force of gravity from the Earth on an artificial satellite of mass 1000 kg what is the size of the fo e exerted on the Earth by the satellite Essentially zero because the satellite39s mass is negligible compared to that of the Earth Much larger than that on the satellite because the Earth39s mass is so large Exactly the same as the force on the satellite Section 47 40 A wheelbarrow of mass M kg was transported to the Moon during an Apollo mission Its weight on the Earth was W Which of the following conditions is found to hold on the surface of the Moon Mass and weight of the wheelbarrow are reduced by the same fraction to 16 of their values on Earth The mass of the wheelbarrow remains the same but its weight on the Moon is less V mass of the wheelbarrow remains the same while weight is found to be zero because the wheelbarrow is at a large distance from the center of the Earth Section 47 41 How many forces are acting on the space shuttle when it is in a circular orbit around the Earth Ignore forces from ven distant objects such as the Sun and Moon 39 One force acting outward away from the Earth to keep the Shuttle from fallin Equal and opposite forces acting toward and away from the Earth so that the shuttle always 9182006 527 PM Freedman Universe 7e Ch 04 9of9 remains the same distance above the Earth39s surface One force acting toward the center of the Earth Section 47 42 Halley39s Comet is named after Edmund Halley Why 39 Edmund Halley discovered the comet on Christmas Day Isaac Newton39s birthday Halley used the comet as a test of Newton39s law of gravitat39on sed the newly discovered comet to illustrate his theory of gravitation and named it after his friend Edmund Halley Section 47 43 Which planet was predicted to exist mathematically using Newton39s theory of gravitation mbined with careful observations of the motion of another planet before it was discovered observationally quot Vulcan Section 48 44 The tides produced in the Earth39s oceans by the Moon show which of the following patterns 39 Two high and two low tides per month 7 One high and one low tide per day 39 Two high and two low tides per day Section 48 45 The Moon is not the only object to exert a tidal force on the Earth The Sun does so also How strong is the tidal force exerted on the Ear by the Sun compared to that exerted by the Moon quot Less than 110 as strong because the Sun is so far away 39 Eight times as strong because the Sun is much more massive than the Moon Half as strong because the Sun39s large mass partly compensates for its greater distance from the Earth Submit I Reset I Quesu39on Mark Percepu39on licensed to Bedford Freeman amp Worth Publishing Group LLC 9182006 527 PM Freedman Universe 7e Ch 05 10f7 Freedman Universe 7e Ch 05 Section 51 1 The first person to prove that light did not travel at infinite speed was V Galileo Galilei V Olaus Rumer V Albert Einstein Section 51 2 In Galileo39s attempt to measure the speed of light by timing the passage of flashes of light between adjacent hilltops what would have been the light travel time between him and his assistant if the hills had een 3 km apart His assistant39s reac ion time wou have had to have been much less than this time interval for this experiment to have been successful V 10 8 second or 10 ns 10 5 second or 10 us 10 2 second or 10 ms Section 51 3 A flash of light is transmitted simultaneously through two parallel tubes of length 1 km one evacuated the other filled with water Detectors sense the arrival times of the light flash at the nds of these tubes at wi be the relationship between arrival times of these light flashes V The flashes of light will arrive simultaneously at the ends of the tubes because light always travels at the same 5 eed V The flash will arrive earlier through the waterfilled tube V The flash will arrive earlier through the evacuated tube Section 52 4 An electrically charged object moving at a constant speed in a straight line is found to generate an oscillating electric field part of a moving electromagnetic wave a magnetic Ie V a gravitational field Section 52 5 What limitation is placed upon the possible wavelengths of electromagnetic radiation by Maxwell39s equations which govern the behavior of this type of radiation There are no wavelength limits either long or short V Wavelengths are limited to those shorter than radio waves of about 1 meter in length 9182006 632 PM Zof7 7e Ch 05 Wavelengths are limited to those around that of visible light roughly from ultraviolet to infrared radiation All other radiations eg X rays radio are NOT true electromagnetic radiation Section 52 5 The frequency associated with blue light compared to that of red light is V e same because both red and blue are part of the visible light spectrum lower higher Section 53 7 If an object is a perfect blackbody then 39V it emits no ene it emits energy only at certain welldefined wavelengths called spectral lines V 39 emits energy with a continuous distribution that peaks at a certain wavelength dependent upon temperature Section 53 8 A perfect blackbody is socalled by scientists because the sha e of the spectrum of energy emitted by it has a fixed shape independent of temperature and only the emitted intensity at each wavelength changes with the blackbody39s tempera ure it absorbs all energy falling upon it and emits a characteristic spectrum of radiation whose intensity as a function of wave ength depends only on its temperature it absorbs all energy falling upon it and emits no energy at all hence its name Section 53 9 A blacksmith heats a piece of steel until the wavelength of maximum emission of radiation is measured to be 1 in the infrared part of the spectrum How would he have to change its temperature in order that this peak wavelength would move o 05 WT or 500 nm in the visible spectral range He would have to cool the steel to half its temperature He would have to raise the temperature by a factor of 24 or 16 He would have to double its temperature Section 54 10 As an asteroid moves out into deep space after coming close to the Sun the peak wavelength of its emitted electromagnetic radiation will move from infrared toward visible wavelengths as the asteroid cools 9182006 632 PM Freedman Universe 7e Ch 05 3of7 increase from infrared toward microwave wavelengths not change at all intensity of radiation at all wavelengths will decrease with no change in the peak wavelength because the asteroid behaves like a black body Section 54 11 The energy emitted per second by the Sun is greatest at a wavelength of about 500 nm The energy emitted per second by a star having half the temperature of the Sun would be greatest at a wavelength o a out 7 1000 nm in the infrared V 250 nm in the near UV 8000 nm in the infrared range 16 times 500 nm Section 54 12 Suppose the Sun had a temperature of 17400 K three times its present temperature but had t e same size that it has now How much more energy would the Sun emit per second 3 times more Section 55 13 Suppose a light source is emitting red light at a wavelength of 700 nm and another light source is emitting ultraviolet light at a wavelength of 350 nm Each photon of the ultraviolet light has either more OR less energy than each photon of the red light depending on the intensities of the two light sources half the energy of each photon of the red light twice the energy of each photon of the red light Section 55 14 The ratio of the energy of a photon of X rays of wavelength 005 nm to that of a photon of visible light of wavelength 500 nm is 7 1 Photons of electromagnetic radiation all have the same energy but more photons per second are emitted by an Xray source than by a visible light source 10000 110000 Section 55 15 The photoelectric effect is 9182006 632 PM 4of7 7e Ch 05 V the change in the direction of a beam of electromagnetic radiation as it enters a transparent medium such as glass 397 the emission of electrons from a metal surface when it is illuminated by light 7 the darkening of certain types of glass when exposed to sunlight Section 55 15 The first person to show that light traveled in wave packets or photons in which the energy of a photon depends on its wavelength was 39V Thomas Young 39 James Clerk Maxwell 1 Albert Einstein Section 55 17 In a beam of radiation from a blackbody the amounts of energy per second at an ultraviolet wavelength of 300 nm and at an infrared wavelength of 800 nm are found to be equal In this m how do the numbers of photons per second at each of these wavelengths compare There will be equal numbers of photons at each of these wavelengths C There will be more IR photons than UV photons 39 There will be more UV photons than IR photons Section 56 18 Spectral lines were first discovered almer by passing an electric current through rarified hydrogen gas and splitting the resulting light into colors using a prism by Fraunhofer by a close examination of the spectrum of the Sun using a prism to spread out this spectrum Kirchhoff by dropping chemicals in the form of powder into a very hot flame and looking at the resulting light through a prism Section 56 19 The presence of dark lines in the solar spectrum the socalled Fraunhofer lines means that V interplanetary gases have absorbed light at specific wavelengths a cooler layer of gas overlies the deeper hotter layers of the solar atmosphere a hotter layer of gas overlies the cooler layers of the solar atmosphere Section 56 20 A hot dense gas produces U a continuous spectrum with energy emitted at every wavelength 9182006 632 PM Freedman Universe 7e Ch 05 50f7 7e Ch 05 an emissionline spectrum with bright lines against a dark background an absorptionline spectrum with dark lines against a bright background Section 56 21 When heated in a flame small quantities of different chemical elements emit light only at specific wavelengths called quotspectral linequot emissions The pattern of these emission lines as a function of wavelength is 7 the same for all elements except that one line a different line for each element is missing from the sequence V characteristic for each element but differs from element to element 7 the same for all elements but with different relative line intensities for different elements Section 57 22 The person who first showed that most of the mass of an atom is concentrated in a very small volume at the center of the atom was 39 Kirchhoff B h o r Rutherford Section 57 Box 55 23 Elements that have similar chemical properties in the periodic table of elements occupy a small block of adjacent rows and columns quot are in a single vertical column 7 are in a single horizontal row Section 57 Box 55 24 Two isotopes of an element differ from one another because 7 they have the same number of protons but different numbers of neutrons in their nuclei sum of neutrons and protons in their nuclei is the same but one isotope has one extra neutron and one ess proton while the secon isotope one more neutron and one less proton V they have the same number of neutrons but different numbers of protons in their nuclei Sections 57 and 58 25 An atom of singly ionized magnesium has 12 protons in its nucleus How many electrons surround this nucleus 139 3 7 11 12 9182006 632 PM 60f7 Section 57 25 An electron is added to a completely ionized hydrogen atom to make it electrically neutral How much extra mass is added to the atom in this process expressed as a fraction of the final Section 57 Box 55 27 A neutron is combined in a nuclear reaction with a proton to make a heavy hydrogen nucleus This nucleus then acquires sufficient electrons to become electrically neutral How many electrons will this heavy hydrogen atom contain C 2 1 None Because the neutronproton combination is already neutral Section 57 Box 55 28 Tritium is a radioactive form of hydrogen in which the nucleus contains one proton and two neutrons How much more massive is this nucleus than that of ordinary hydrogen The 5 me mass because this is still a hydrogen nucleus 397 Three times as massive V Twice as massive Section 57 Box 55 29 The metal nickel Ni occupies position number 28 in the periodic table How many electrons will need to be removed from a neutral nickel atom to completely ionize it leaving only a nucleus 1 27 28 Section 58 30 In order to produce the primary Halpha Ha Balmer spectral line in emission an electron must jump between which two energy levels in the hydrogen atom 7 From n 2 ton 1 the ground state Fromn 3ton 2 i From n 3 ton 1 the ground state 9182006 632 PM Reminder Don tbe alarrned ifthe materialI cover always seems dif cult I spend the most time on the most dif cult concepts in the book Tutoring Group Study Of ce Hours Feedback How can I make things easier for you using technology Post notes before lecture 7 On Sunday you will nd Tuesday and Thursday notes for that week What else iEmail list 7 Other technology Eventually We Want to be Keywords able to explalrl me 0 Diurnal Sidereal 0 Local Time 0 Universal Time 0 Ecliptic Nakedeye astronomy had an important place in ancient civilizations Positional astronomy 7 the study or the positions or ooiects in the sky and how these positions change Nakedeye astronomy 7 the sort that requires no equipment but human yision xtendsfa back in time 7 British isies Stonehenge e atiye American Medicine Wheel 7 Aztec Mayan and incan tempies 7 Egyptian pyramids Ei ht ei ht constellations cover the g y g Modern Constellations entIre s y On modern star charts the entire sky is diyided into 88 re ions Ancient peopleslooked and 9 Each isaconsteiiation at the stars imagined groupings made pictures in the s Most Stars iri a Constellation are nowhere rie We stiii rerer to many or a one these groupings am e Astronomer ii hem They 0W We be constellatlons from ciose together because the Latin ror group they are in neariy the stars same direction as seeri from Earth Question Rotate B around A without slippage like a gear How many times does B rotate 1 1 time 2 2 times 3 314 times 4 6 28 times A is giued to the table Question Question otate B around A without slippage 39 RP Zte B around A Without ShPPZge like a gear How many times does B Ilka a gear HOW many tlmeS does rotate B rotate 1 1 time 1 Same as when B was a quarter 2 2 times 2 More than when B was a quarter 3 3 14 times 3 Less than when B was a quarter 4 628 times A ls glued to the table A ls glued to thetable Question Rotate B around A Without slippage Therefore like a gear How many times do 5 7 B mtate39 I Break the rotation of B into two parts rotation about the xed quarter and rotation about itself IfB does not rotate about itself it still rotates around the xed quarter 1 Same as when B was a quarter 2 More than when B was a quar 3 Less than when B was a quarter A ls glued to the table The appearance ofthe sky changes during the Ea h s Motion in Orbit course ofthe night and from one night to the next Stars appear to hse lh the east slowly rotate about the earth and set 0 Diurnal Daily 0 Annual Yearly Thls diurnal or dally actually caused by the 247h0urrotatlon of the earth 0 What happens to lines as star a small amount up and down when star is very very far away Lines still look parallel Sidereal Time Prep Sidereal Time Prep 0 What happens to lines as star moves to 0 What happens to lines as star moves to the right the right Lines become more nearly parallel Sidereal Time Prep Sidereal Time Definition From text A Sidereal day is the time between two successive upper meridian passages of the vernal equinox By contrast an apparent solar day is the time between two successive upper meridian crossings of the Sun Sidereal Time star time Solar Time sun time At 1 line points at sun distant star Sidereal Time star time 0 Solar Time sun time now pointing at star only 2 2 Sidereal Time sidereal star time h 39quots since 1 Solar Time quotquot9 395 I39IOW sun time At 1 pointing at line ax distant POIquotts 9 9 star only Which is 3 We we 5 longer distant 960 star 5 1 Sidereal day 2 Solar day 2 24 Sidereal Time sidereal star time hwrs since 1 Solar Time quotquot9 395 I39lOlN sun tlme At 1 pointing at line xquot distant POIquotts 5 star only Which is 3 We we 5 longer distant 960 star 9 1 Sidereal day 2 Solar day by N 4 min 39 To vernal equinox See also Box 22 page 35 Local solar noon 7 in local solar noon on Manh 21 is on March 22 Earth on March 21 Earth on March 22 iiiuminaied Dark day side r night side Andromeda Rotation of the Earth Cygnus is overhead as seen from California 300 p load time to Earth as seen from above the North Pole Where is Cygnus 24 solar hours later 1 West illuminated Dark day slde 39 2 East Retal t the E Andmmedu all of quoth 3 Vertical a Person Cygnus is overhead as Culifern seen from caiitamia 00 FM4 local time a Earth as seen from above the Nerth Pele Where is Cygnus 24 solar hours later 1 West Illuminated Dark day side nigh side 2 East Andromeda 3 Vertical Rotation of the Earth It will soon be Person in cyanquot i warhead as over the HEM seen from Calitnrnia Paci c Ocean 1 Earth as seen from above the North Pole Local Time Vs Universal Time PACIFIC TIME ENYRAL MouNTAm c 9 TIME x Eaith s Motion in Orbit Diurnal Daily 0 Annual Yearly Stars appear to slowly shi in position throughout the year This is due to the orbit of the earth in the ecliptic plane around the sun If you follow a particular star on successive evenings you will nd that it rises approximatel 4 minutes earlier each night or 2 hours earlier each month The Seasons What causes the seasons 1 Distance of the sun from eaIth 2 Tilt of Bath with respect to the ecliptic plane What causes the seasons 1 Distance of the sun from earth 2 Tilt of Earth with respect to the ecliptic u A month39s motion nhhe Eanh alnng its orbit What causes the seasons uenh psi 1 Distance of the sun from earth h I see p 2 Tilt of Earth with respect to the 39 quot quotquot quot ecliptic h a II Ii lsuuthzmh sphere F swan e norrhern hemisphe Nenh pole p g n I re in m quotmmquot hemisphew autumn in she southern hemisphere Nenh peie summerln the souihern hemisphere North pole I cum pole Nnnh pole 23 North pale I South pole Summer in the nonhern hemisphere n r sunm I 5mm For Au nmn the northern hemisphere Winter In the southern heMISth South poie spring in the southern hemisphere Renmnmer I Rotation axis always points in same direction With respect to far away stars I Looking down on north pole Earth rotates CCW about its axis and CCW about sun quotWNWquot The seasons are caused by the tilt of Earth s axis of rotation with respect to ecliptic The Earth s axis of rotation is not perpendicular to the plane of the Earth s or It is tilted about 2312 away from the perpendicular The Earth maintainsthis tit as it orbits the Sun with the Earth s north pole pointing toward the north celestial pole msunmwim midday winlushy Seasons During part or the year the northern hernisphere or the Earth is tilted toward the Sun As the Earth spins on its aXlS a point in the northern hernisphere spends rnore than l2 hours in the sunli ht The days there are lon and the nights are short and it is summer in the nort ern hernisphere and Winter in the southern hernisphere The surnrneris hotrlotorlly because or the extended dayllght hours but also because the Sun is high in the northern hernis here s s As a result sunlight strlkes the ground at a nearly perpendicular angle that heats the ground efflclerltly Iquot T 5quotquot iquot quotquot39quot b quot 5 5quotquot iquot Mmquot This situation reverses Six rnonths later From Chapter 2 quiz Questions 39 The constellation Cygnus appears Textbook problems 10 11 20 36 47 CD Quiz also at htw bs threeman comuntverse7e for Chapter 2 34914 15 23 24 overhead to an observer in the state of midnight on a 1 In the westem sky 2 Overhead of course 3 In the eastern sky From Chapter 2 quiz Dgrk quot39939quot we 39 The constellation Cygnus appear overhead to an observer in the state of Illuminu ed day s e Andromeda A Coordinated Time or UI C yVhich will be 10 PM Montana local i lt 9 g 1 In the western sky 2 Overhead of course 3 In the eastern sky PM IonII Dime up Earth as seen from above me North Pole Book Question 20 Group Question 39 Why is it convenient to divide the Earth into Pans Humquot warns to CBlebTate New Year time zones Eve more than three times in a 24 hour 39 period She is in Which way s her assistant tell the pilot to fly Is it possible East msuNH a z 0 39 Paris Hilton wants to celebrate New Year s Eve many times She is in DC Which way does her assistant tell the pilot to fly Does she make it 39 Now she wants to tan extra long in herjet with a sun roof She starts in DC Which way does her assistant tell the pilot to fly Group Question P39FP Nquot Z MAUNH z 0 lnllnxehumbudmenldurlnqlhe lsl mo marriahynrutterrhethaanmad Outline for 31 October Tuesday muting at highlnnds Forminn Elmli rmm rue impls m threadamelntennbumblrdmenlpe39 a i a r o E amourrat mxklng Impnu Iuyllghl amend during muzsz hilllanyuvx l 3 z I quotme nature present billion a years Key Words Theories How did the moon form W W mare thturatmaha W center Elf rnass W WWW Getting data to answer this was one ofthe 1 science objectives for the Apollo program era er Heeewli synchrunuus Mam What was the social driving force for the WWW Apollo program W impactcrater mm W Theories How did the moon form n ammrmrh thmnmrw ntux mm H mum than m Manama sslun a Part etEarthtere away because Earth was vapldlyvulalmg 7 Where are the chunk eerhe trerhv e Wuuld Expect rhere srrhrlarrty rh Meeh aha Earth racks Capture e Wandering rheeh was captured by Earth s gravity 7 oerhpmer slmulalluns shewthat rt is highly unlikely Curcreatlun e Farmed at sarhe trrhe but separately 7 h heehtehtrhrsrhateh ulllslunal Elena theury zed ehreet collided wrth Earth a Ouvcunenlbeslguess sun Culllslun e Mavssl mmwwrwrm mem mwm Question The terminator on the Moon is a line A rth and south lunar po S passing through the center ofthe largest mare lmbrium representing 0 of lunar l ngitude B between the near and far sides ofthe Moon C between the solarilluminated and dark emispheres D along the equator between northern and southern hemispheres Question The terminator on the Moon is a line mbrlum representing 0 of lu longitud e B between the near and far sides ofthe Moon between the solarilluminated and dark hemispheres D along the equator between northern and southern hemispheres Question lfyou were standing on the Moon with Earth in view how much time would n two successi e A about 1 synodic month B about 1 day C about 1 sidereal month D in nite time because the same side ofthe Moon always faces toward Earth Question If you were standing on the Moon with Earth in view how much time would elapse between two successive quotEarthrisesquot A about 1 synodic month B about 1 da C about 1 sidereal month D in nite time because the same side of the Moon always faces toward Earth Question M aria are A bright streaks radiating away from young fresh craters B isolated regions of heavily cratered highland terrain C long sinuous valleys formed by ancient lava rivers D ancient lava oodplains Question Maria are A bright streaks radiating away from young fresh craters B isolated regions of heavily cratered highland terrain C long sinuous valleys formed by ancient lava rivers D ancient lava oodplains Outline for 31 October Tuesday The Moon 20 minutes Mercury 55 minutes Interesting facts Mariner 10visited in 1974 and 1975 MESSENGER MErcury Surface Space ENvironment GEochemistry and Ranging will orbit startin in 2 Key Terms greatest eastern elongation greatest western elongation solartransit 1to1 spinorbit coupling 3 to2 spinorbit coupling scarp Observations Observing Mercur What are best conditions to observe Unusual spin How suspected to be unusual How to make a guess that will make you famous Craters How similar to the moon How different Unexpected magnetic field Why unexpected How measured It is hard to see Earth s orbit Mercury at greatest casrcrn elongation Mercury39s orbit Mercury at greatest western elongation Visualizing Mercury s orbit Textbook Chapter ll mime materla Visualizing Mercury s orbit WD Textbook Chagter l l mime malaria Observations Observing Mercury What are best conditions to observe Unusual spin How suspected to be unusual Why unusual How veri ed How to make a guess that will make you famous raters How similarto the moon How different Unexpected magnetic field Why unexpected How measure Noname rotation synchronous rotation Draw ball and arrow atA B C D he Moon39s rotation always keeps the same face toward the Earth due to synchronous ation 1 mm m Moan dons vomit and we no me MW in m mm we mild 5 aquot gun a m Mm 5 only on 5m 4 the Mus m an um Mercury s urmax permd s 88 days Mercury s rutatmn permd s 58 days Draw ball and arrow atA B C D Draw ball and arrow atA B C D Mercury s urmax permd s 88 days Mercury s rutatmn permd s 58 day I4 22 days to gel to A Mercury s urbxta permd s 88 days Mercury s ratater permd s 58 days 2253 0375 Draw ball and arrow atA B C D Draw ball and arrow atA B C D First rotate aro d 0375 of a full turn 884 22 days to gel to A Mercury s urmax permd s 88 days 2258 0375 Mercury s rutatmn permd s 58 8 days 884 22 days to gel to A Mercury s urbxta permd s 88 days Mercury s ratater permd s 58 days 2253 0375 c Receding side 1 125 turns lt VVWI Reflected waves are Doppler shifted 075 of 39 to longer wavelength a fu adio waves turn from Earth Reflected waves 1 are Doppler shifted to shorter wavelength 15 turns 0375 of a turn A J Approaching side 884 22 days to get to A Mercury s orbital period is 88 days Mercury s rotation period is 58 days Observations Heavily Observrng Mercury cratered What are best conditions to observe surface Unusual spin L555 How suspected to be unusual 55 Why unusua craterlng than moon How veri ed How to make a guess that will make you famous 39 mly Craters plain How similar to the moon scams How different No Unexpected magnetic field evidence Why unexpected How measured tectonics 5 E r I E lava uoled Mercury s Inst mnlraded to farm Ihis scarp r at rhisaa V when Observations Observing Mercury 7 Whatare pest cdhdltldhs td ubseNe Unusual spin 7 Huvv suspected td be unusual 7 Why uhusual 7 Huvv verlfled 7 Helth make a guess that Wlll make yuu rarhdus Craters 7 Huvv slrhllartd the rhddrr 7 Huvv dlrrereht Unexpected magnetic eld 7 Why unexpected 7 Huvv measured The magnetosphere blocks the solar wind from reaching the surface of the planet QUEStIOI IS 6quot is relatively dif cult to observe details on the surface of Mercuryfrom Earth because 7 A detall lS upscured py prlght gluvvs rrdrh hut regldhs drrhdlterr surrace heated by the lrlterlse suhllght 7 El lts urbltalvvays keeps ltdrr the dppdslte slde cut the Sun rrdrh Earth 7 C lt l a small uplect that always appears cldse tn the Sun lrr the sllt 7 D lts surrace lS always cdrhpletely cdyered lrr clduds Outline for 11 October Thursday 0 Questions about Comparative Planetology 20 minutes The Living Earth ChapterQ oftext 55 minutes Why are craters circular if asteroids can strike the surface at angles httpdeepimpactjplnasagovlsciencecrateringhtml Take 10 minutes Review Questions For Topics Covered in Lecture and Reading t Do all the planets orbit the Suh in the same direction Are all ofthe oroits circular What are the characteristics of a terrestrial planet What are the characteristics of a Jovian plane 7 4 in what ways does Plu o hot rit the usual oiassirioatioh of either terrestriai Ol JOVlal i planets What is meaht bythe ayerage density of a planet What does the ayerage density of a planet tell us 6 in what ways are the largest sateiiites simiiarto the terrestrial planets in what ways are they different 7 The absorption iihes m the spectrum of a planetorsatellite do hot indicate the oompositioh of the planet or satellites atmosp ere yhot Why are hydrogen and helium abundant in the atmospheres ofthe Jovian oiahets but present h only small amouhts in the Earth s atmosphere com or oo 9 What is an asteroid Nhat is a comet lri WhatWayS are these mirror members ofthe Solarsystem like orunlike the planets Review Questions For Topics Covered in Lecture and Reading 10What are he asteroid belt and the Kuiper belt Where are they located How do the objects found in these two regions compare 11 What is the one giece of evidence that impact craters are actually caused y impacts 12What Is the relationship between the extent to which a planet or satellite is cratered and he amount of geologic activity on that planet or satellite 13How do we know that the surface ofVenus is older than he Ear h s surface but ounger than the Moon s sur ce 14Why do smaller worlds retain less of their internal heat 15Huw L 39 H equot 39 of catering on the planets surface 16How is the magnetic eld ofa planet different 39om that of a bar magnet Why is a lar e planet more likely to have a magnetic eld than a sma planet Review Questions For Topics Covered in Lecture and Reading t yes pit aimost eiiipticai 2 What are the characteristics or a terrestrial planet Srna i dEnSE rockyi warmeri tewer Sa Elll ESi rio rings 3 Whatare the characteristics UfaJwian planet Lame VlEI EVlSEi oasario ll uld culuet mam sateiiites ario ririos iri what ways ooes Plutu riotit the usuai ciassmcatiori or eitherterrestriai EIYJEIVlan piarietsr Distarice is simiar to Juvlafl piariets Composition simiiarto Earthiihe piariets WhatismeamWtheaterauedenleUfaplaneWWhatuuestheeyelaueuenslwufaplanettel us Massoiyioeopyyoiume Derisi cariheipteiiusapoitw atthepiariet smaoetrom ets iriwhatwarsare s iri what vva s are the iaroest sateiiites simiiarto the terrestrial p ari different imiiar SlZEi soiio suriacei put iower oerist The apsorptiori iiries iri the spectrum or a piariet or sateiiite oo riot riecessarw irioicate the cuwusniunuftheplanetursatellite salrmsphere Why riot oortairispiecesotthesoiarspectrum arioeriectsiromEa ere WW are hyorooeri ario heiium apurioart irithe atmospheres otthe leafl iariets put presert iri oriiy smaii amourits iri the Earth s atmospherev Temperature ario oray w orooeri ario Heiium cari escapetrom Earth pit tromtupiter it caririot pecause Earth has hiohertemperature ario iowe Eraltatlunal pui Jupner has iowertemperature are higher oraytatioriai puii WhatisariasteroiurWhatisacomeviriwhatwaysarethesemriormempersotthesoiarsrstem like urunlike the planet57As12ruiu leDEWi cometisicy aoth orpit surii as oo piariets Smaller ariomoreotthemtharipiariets r i3 Howd butyo Review Questions For Topics Covered in Lecture and Reading i0 What are tne asteroid belt and tne Kuiper belt Where are they located How do tne obiects round in tnesetwo regions compare Asteroid beit between Mars and Jupiter Kuiper belt is near orbit or Neptune and contains comets ii What is tne one piece or evidence tnat irnpact craters are actually caused by impacts Meteorite compounds at location of crater Circular craters i2 What is tne relationsnip between tne extent to wnicn a planet or satellite is cratered and tne arnount or geoiogic activity on tnat pianet or satellite Geologic activity riiis in craters o we knowthatthe sunace or Venus is oidertnan tne Earth s sunace ungertnan tne Moon s surface yenus nas srnaii craters Bigger ones have been erased by geoiogic activity Smaller oiderworids aye iess geoiogic activity 4 ii u iiiaii i in ii ai uiia ai at volume ratio is nigner More sunace area rneans rnore radiation How does tne size or a terrestrial pianet inriuence tne arnount or catering on tne pianets surface Smaller and older rneans iess geoiogic activity Smaller radiates neat raster and so geoiogic activity continues tor a snorter amount of time How is tne rnagnetic rieid or a planet dirrerent trorn tnat or a bar magnet Why is a large pianet rnore likely to have a rnagneticrieidtnan a srnaii iariet Earth s field is made b bulk cure El rnutiun uttiuidin armagnet sfieid Outline for 11 October Tuesday Questions about Comparative Planetology 39 The Living Earth Chapter 9 oftext What was mat hump Key Words albedo northern and southern atmospheric pressure I39 Tts aurora plural aurorae 0 gass39ng bios ozone ozone layer Van Allen Radiation belts m agnetosphere Guiding Questions 1 What is the greenhouse effect How does it affect the average temperature ofthe Earth How does our planet s magnetic eld protect life on Earth N 3 Why is Earth the only planet with an oxygenrich here 4 What are global warming and the ozone holequot Why should they concern us A highly debated plot What happens next Now predict what will happen Do we need to worry Global Temperatures AnnualAveriwz Five Yeav Aways X Tempevaluve Anomaly WE wen sea was 192 mu wan man me At what point should we worry Remnsuuned Temperawre N W 9 H mm E n 47 7 l l v w E E n nmmmmmmwmmm Protective Shields Atmosphere 39 Magnetic eld Atmosphere Memmhem Sualasphua msvheu u mlu u zn u m Eul Yamyenmul 0a Atmosphere On Predictions If we know how atmospheric chemistry affects climate why not engineer a solution Energy Balance Three modes of energy transfer Convective Bulk movement of mass Conductive jiggling material but no bulk movement of mass Radiative why you feel colder when it is colder outside in a room that is always 70 degrees Energy Balance Simple model Sun inputs energy to big ball Earth What happens to temperature Energy Balance Simple model Sun inputs energy What happens to temperature Increases eep temperature constant we need a way orgening rid ofit once we are at an acceptabletem perature Energy Balance Can t convect energy to space Can t conduct energy to space Need to radiate And as something is heated up it radiates more remember blackbody curves Energy Balance the full picture yawn Aimime 3w Swims M mm The Greenhouse effect The Greenhouse effect Visible light passes Two usages through with ease An effect that occurs on a planet with an Earthlike atmosphere An enhancement ofthe above effect due to human activity The Greenhouse effect The Greenhouse effect Whywon t temperature continue to Why doesn t radiation get absorbed by increase greenhouse gasses on the way down How is Global Warming Related How is Global Warming Related to the Ozone Hole to the Ozone Hole Sepxemblzr ma Both ga lfsged by human a tpi39il htytubut you can have one without the other Ozone in Earth s Atmosphere ru sr zn w 4n 1 n Ylmneliwlel la Group Questions Make an argument to justif the statement The temperature trend is ancequot 8 n a z m o n m n me help justifyrefute each ofthe statements 7 Due tel chahce l 2 3 7 Nut duetu chahce l 2 3 Protective Shields Atmosphere 39 J 39 39 Magnetic eld The Solar Wind The Solar Wind A plasma ls created by lehlzlhg aterhs sending nut phatn sun ls the source at 39 r a plasma traveling at ll l kml s When the plasma gets neerEanmhe charged particles are lhrluehceu by Earth39s internal magne clield path a partlcle takes ls cerhp lca 7 lens and ndtu retate aruund rhaghetlcrlele llhes Mathevmmev mgInuulmtectlveishleld l Imlmgnll Mml electrerls te 7 wwwspace The Magnetosphere The solar wind distorts Earth s dipole magnetic eld to form the magnetosphere 39 Uhxn n mm v Can t keep up m m quotWigwammat quotSwammwemmumquotemisszu Review Technique Jupiter s atmosphere mostly H2 and He Almost no H20 or 002 which re greenhouse gasses which prevent heat from Earth s interiorfrom leaving has a constant temperature Jupiter is ooling is it because it does not have greenhouse gasses Outline for 16 November Thursday Jupiter and Saturn rbit Sur ce Atmosphere Key Words aerusui Gamean sateihtes hydrucarbun inturus annuitatmn uitrama iava monkn mama mun n msmm mm mug Humming um Mmmanmwmmkmmmum Etheimgunhhenuiiitulbemklvutuvehunmtugeu7lx Jupiter s Galilean Satellites Galileo observed using telescope Galilean satellites Jupiter s Galilean Satellites Would you be able to see a transit Galilean satellites Measuring Their Orbital Period HOW Galilean satellites Measuring Their Diameter HOW Galilean satellites 39 39 Jupller Measuring Their Mass HOW Synchronous Rotation Why does it happen Q 124 Magic Numbers Galilean satellites Jupiter s Moons m mack am my ManuallyINDYquot Nuleullvirungnawntumgranuleumautumnarhkureilnu amjllvkm awrmmamm uamuurmwmmmmu How can we sort this out Solar System Formation Video fashion to our solar system but on a smaller scale In me mm pans 0 both me solarand Jovian nebulae only ygrainssurv39vem PromJupiter Pmmsun in the outer reaches while or these nebulae in and rocky grains survive Jupiter s Moons lo Predicted to be much like Earth s moon Wk mam smamkm 0mm Anniedlnnmlvamluplm Naked1mm my lulhaum um m mumManama mm mm W mlhlhalmge arm guanineM4wa Mammal1947 Tidal Heating l punTwoquot mum plumiun rmmm b Ealileo Navamhm1597 a Vnyagur 1 Maxi my Flux tube Plasma torus Plasma torus Jupiter n rom coldquotions 10000 K I Green39em o f Magnet eld lme Purpletemusion lromquotwarm39 Ions 600000 K Jupiter s Moons mm i nmnankm Gamma Wu mam Mm Avasedan Naked1mm my Romany um um 4mmManama mm mm W mxmume nine menu mm m m 91th Europa is covered with a smooth layer of ice hat may cover a worldwide 0 ean WW2 cumpused pnmaniy u yuck Euvupa iscuveved Wm a smuuih iayev uiwaience The 5mm has havdiy any new mumaimg a geniugmaiiy acme hisiuvy Asvmiu iidaiheaimg is vespunsibie quumpa s miemai heai Mmevaisdissuwedmims man may expiam Euvupa s induced magneim eid Ridges produced by hiding and tanking n the surfam lung that indicate a subsurface layer id water or soft ice 394 Sm mummy a walko riuulu unm cracks and ice rafts of liqu disturbanze upling omo r the suvface r r M m a A Llnear ealures Shaw haw s an 9 fi lyguher Q39W Jupiter s Moons km mm my 4 4ymm Nuxeullphuluhl mmmmuam human mummwupu rump7615mksulenhnmlguMlhenulmuhunchuAnuebunmlargedhx mumquot and v mm Innaquot young kwuua Ganymede Ganymede s mam ameyemmem and pmbamy has a metaHm cuve hasasuv Hsm shung mag im gym and a magnemspheve a u may ave be n mmmnmsvasm mm as1 An mducedmagnehc he d sugges1sawh mmhasa a m hqmdwatev mam me suNace 39 gt g 1 a 539 w u a Two types oflerrain are found on the icysurface of Gan ede 7 areas uf dam anmenp heavw watered surface 7 regmns uf heav y gruuved hghterrcmured yuunger terram Liquid water may also lie beneath the cratered surfaces of Ganymede and Emma mm 1 mquotquot in Hymn m lmnwve 39 mmawmh Jupiter s Moons n mm AvengedlaunmlvamJuvlul n plmluallownlamumMilInh nkMuunheulelllleilmmlllvluv nonparathmlhlhalmge anhe alanineM4waMuemenlIged7 x Jupiter has dozens of small satellites that have different origins Aseleallyzuumupllennasa tulal e153 knuwn satellltes ln addltlun lathe Galllean satellltesJupltelhasluulsmall lrmev salellneslnal lle lnslee lu s an ll leethe Galllean satellltes lnese emu lnlne plane uHupnel s equatul Tne YEmalnlng satellltes ale small and Inqu ln muen larger ulbltsthat ale nutlceably lncllned tn lne plane ulJupltev s equatuv M nese emu ln e eneman uppusltetu Jupllev s vulatlun mam Ntwvalk Callisto from Voyager 1 Calllslu nas a heavlly metered emsl ulwatel lee Tne sunaee snews lmle slgn ulgeulugl adlvlly becausethele was never anysl nllcanltldal heatlngulcalllsm uwevel senne url nuwn plucesse have elasedlhe smallest males and blanketed lne sunaee Wlln a dark dusty substance Magnetlclleld data seem in suggestthat Calllslu nas a snallewsubsunaee eeean a Mm lb Email1m Ln my mama 392 an mamquot see kml lameer man my Leadlnghahllwhue w quotmam Ludlns hmlxvhem iuralued hailing nmlxpnm l5 higle vellea lv e nne dumuu 153a kml Saturn s Moon Titan Titan has a thick opaque atmosphere rlch in methane nitrogen and hydrocarbons We largest Saturnlan satelllte Tltarl ls a terrestrlal Wurld With a dense rlltrugerl atmusphere Tnese cumpuunds farm an aerusul layer ln Tltarl s atmusphere and pusslbly uver same er ltS surface Wan lakes er ethane Outline for 05 October How does It scale Thursday 0 Questions about scaling 20 minutes 0 Comparative Planetology I Chapter7oftext 55 minutes Are the numbers matching How does it scale How does it scale In computer science In physics and astronomy Economics If one thing increases what happens to something else Other usage Ay T f r How does it scale ypes 0 sea mg In computer science y mx 7 HOW does Java 2 Enterprise Edition orRuby on Rails scale In physics and astronom Mass ofa sphere scales With the cube of its radius y X 7 Energy ux from a blackbody scales With the fourth poWer of its I ternpera ure Economics 5 near a Bang forthe buck 5 a Econornies ofscale Other usage a Level or success scales With the arn ount of quallty practice 7 Amount of paint needed to paint a sphere scales With nt of h ofthe radius Amou paint needed toilla sp ere With the cube ofthe radius the square scales What happens to the X when this line doubles in length length ofthis line List of things that scale linearly Body weight to the number of years after you turn 25 o The mass of a cylinder to its height mphnr2h List of things that scale quadraticly Gallons of paint needed to paint a disk to the radius ofthe disk A nr2 r2 o The amount of light collected from a lens to its radius L mnr2 r2 y Types of scaling y mx2 y I quadratic What happens to the length ofthis line Discuss real life the cost of making a lens does not scale quadratically lfthe radius doubles the cost goes up by a factor of 8 not 4 Why Also the cost of a 15 inch LCD display is about 100 dollars but the cost of a 30 inch display is 1000 dollars What does scaling tell you the cost should be 3 Types of scaling y m1x y 1X inverse x X when this line doubles in length List of things that scale inversely Frequency of a photon and it wavelength k1v because 0 7w Energy of a photon and wavelength E 1 Question How much more energy does a 4 cm radius circular collector absorb than a 1 cm radius collector Same 2x 4x 16x Need more info Area of circle is proportional to r2 A2 is proportional to 1 cm2 1 cm2 A1 is proportional to 4 cm2 16 cm2 Question If the temperature of a blackbody increases by a factor of two what happens to the total energy flux it radiates Same Need more info Question If the temperature of a blackbody increases by a factor of two what happens to the total energy flux it radiates Need more info Total energy flux F is proportional to T4 F1 is proportional to 1 1 F2 is proportional to 24 16 Question Wavelength of a electromagnetic wave is about 400 nm How does its frequency compare to a wave with double this wavelength Same 2x 4x 16x 32x Need more info Question Wavelength of a electromagnetic wave is about 400 nm How does its frequency compare to a wave with double this wavelength Same one half Frequency v is proportional to 1M Mo times v1 is proportional to 1 quaner v2 is proportional to 12 four times Need more info If energy is inversely proportional to Wait wavelength why doesn t a blackbody curve look like this E 1 x Blackbody curve represents amount of energy at a given wavelength As wavelength gets small E goes to in nite but amount ofenergy emitted at that wavelength goes to zero Outline for 05 October Thursday Questions about scaling Comparative Planetology Chapter7 mm Solar System Exploration with Celestia httplwwwshattersnethelestial We shouldshould not send humans to Mars MtFNwwvdeviaman camdeviatian We shouldshould not send MtFNwwvdeviaman camdeviatian humans to Mars Key Words Scaling Parallax Escape speed Jovian planet Comet Asteroid Meteoroid Parallax What letter does my head block most ABCDE Top View of Room sides of ro m q Parallax n13 nearby my Key Questions What is escape speed The velocity needed for something to es ape something else s gravitational u To kick a ball so that it never returns it must leave yourfoot with a certain escape s eed Key Questions Are all the other planets similar to arth or are they very different Do other planets have moons like Earth s Moon There are two broad categories of planets Earthlike and Jupiterlike All ofthe planets orbit the Sun in the in almost the same lane Most ofthe planets have nearly circular orbits Seven large satellites are almost as b39g as the terrestrial planets Cumparable m SlZE tn the planet Mercury The remammg satemes er the sular system are much smaller Key Questions How do astronomers know what the other planets are ma e of Are all the planets made of basically the same material Spectroscopy reveals the chemical compos n ofthe planets The spectrum of a planet or satellite with an atmosphere reveals the atmosphere s composi i If there is no atmosphere the spectrum indicates the composition of the surface The substances that make up the planets can be classi ed as gases ices or rock depending on the temperatures at which they solidlfy The terrestrial planets are composed primarily of rocky materials whereas the Jovian planets are composed largely ofgas The absnmllnn line a quotmugquot m absnlplinn llneel p u nxygzn 01 ls undated in Eink s zlmusphlm m b Interpreting man39s spenrum Why Wleerthah H and 027 l nulllulu N 5 01 2mm Intensity can 690 480 5m 5m 570 mo 630 Wavelength luml a The spenrum at sunlight re ected ham rite Why lS shape su dlfferentfrum blackbudy Why WldEr than H and 027 J cmlnuul quotisquot 01 Earth Intensity ll cu mum o alrhespeetmmatsun ghtteilettedtmmr n I 1 Why lS shape su dlfferentfrum blackbudy 39a espectmm el Europa is almost identical to that of lee lnaiteting that the sudate of Europa is mostly lee nutmtlt 909 ham 9 Ftattlan of incltlent light that is re ected l n L5 2 Wavelength um Dens y The average density ciiany substance depends in pail un its Bumpuslllun An chiect sinks in a nine it its average density m is greater than that utthe uid but HSES it its average density is less than that utthe mm D The teiiestiiai innei planets aie made at yuckyW materials and ave dense ivuri curesi whic gives these planets high average densities The vaian miter planets aie cumpused pllmallly ciiiight e ements such as hyeicigen and helium which givesthese planets iciw av i ge densities can Nam mi Key Questions What is the difference between an asteroid and a comet Why are craters common on the Moon but rare on the Earth Cratering on planets and satellites is the result of impacts from interplanetary debris When an astemid cumet m meteumid cullides Withthe surtace u a tenestiiai planet cii satellite lhe iesuit is an impact ciatei ceciicigic activity ienewsthe sunace and eiases Elalels sci atenestiiai wane With extensive Elalellng has an aid sunace and lntle cii he geuluglc acllvll Eeca se geuluglc activny is queled byintemalheat andsmalleiwuilds u icise heat mciie lapldly as a genelal rule smaiieiteiiestiiai Wuvlds aie mciie extensively Elaleled Key Questions Why do interplanetary spacecraft carry devices for measunng magnetic fields Do all the planets have a common origin A planet with a magnetic field indicates afIUI In erior in motion Planetary magnetic fields lfa planethas nci magnetic field that is evidence that nut in a state cit rnciticin The magnetic elds of terrestrial planets are produced by metals such as iron in the liquid state The stronger elds ofthe Jovian pl nets are metallic hydrogen or by water with ionized molecules dissolved in it quotThere is a theory which states that if ever anyone discovers exactly what the Universe is for and why it is here it will instantly disappear and be replaced by something even more bizarre and inexplicable There is another theory which states that this has already happenedquot Douglas Adams only Extra Credit one Turn in by Nov 30th expect to be asked for a revisionquestion 3 on tinal Annutate this lmagetu shuvvvvhere andfur huvv lung theflrst astrunauts landed on the muurl include references 3 on tinal visitan observatory attend an observation opportunity urplanetarlum Stup by my ottiee a eryuur visit 7 http Ugh sies grnu eduhgellernbsewlng mm 7 http vvvvvv astru umd eduopennouse b page See the This slideWiquot be posted on the course we 7t r more details In the news http lewvsclerlcedailv mmveleasesZEIEIBl iiooi lmEIQmEIQ htn Outline for 07 November Tuesday Recap Moon Mercury Venus Mars Outline for 07 November Tuesday Recap Moon Mercury Venus Mars Why are we interested in Mars Video On Mars 10 minutes The red planet Mars 05641 R44 1999 On reserve in Johnson Center Library The Complete Cosmos Venus and Mars Earfh s Sisters Johnson Center DVD QB 442C66 2003 disc 3 On reserve in Johnson Center Library Landers have explored the surface of Mars It is hard to see Angular mameiev queamn MM hm Key Words crustal dichotomy dust devil favorable opposition perma 39ost residual polar cap runaway icehouse effect Outline for 07 November Tuesday Recap Moon Mercury Venus Mars Moons Orbit Surface The two Martian moons resemble asteroids Dnlmos 5 hastwo smaw footbaHrshaped satetesthat move m ormts dose to the surface ofme p anet They may he captured astermds or may have formed m arm around Mars outofsmarsystem menus Outline for 07 November Tuesday Recap Moon Mercury Venus Mars 2001 June 1 a own a Q om 01M Unfavorable Mars ism mu he39 Earthbased abservatians af Mars are best made during favarable appas invalalvlotpmsmcn Iom whenemuuen k 395 mm Dmhaunn H al l napalmn why WWW quoty m 4 I The best Earmnasee mews of Mars are untamed when Mars 5 swmmtaneous y at opposmon and near permehon Outline for 07 November Tuesday Recap Moon Mercury Venus Earthbased Observations AsmardayonMarsws near ymesame engm as on Earth Marshaspmarcapsmat expand and shnnmm The Mama vulcanuesav t ft valley andd volcanoes and canyons on Mars su Unmanned spacecraft found craters as n riedrup riverbedsi but no canals Maman volcanoes and the Valle Mannens nn valley were formed by upwelling plumes of magma in the mantle SimsIncl Syvln m nmmnsmm in am on that a composition ufan er mure re ent lav Mars has no planet derst re merit M aman a ide magnetic field at present but may have had one in the ancie tpas t munquot mmnm numeral mm or rea s a mum Subunnam n at u n nud t echemical lava is different from that The heavily cratered souther older and abou 39 the smooth no Olympus Mons n highlands a e Igher in elevation than hern lowl d The origin ofthis crustal c mpletelyunderstood an s dichotomy is not Surface features indicate that water once flowed on Mars Flash ood features and dried riverbeds on the Martian surface indicate that water has owed on lea Martian surface today A Wu llahminlul Polar Ice Caps Mars s polar caps contain frozen water a layer of perma 39ost may exist below the Martian regolith and there may be liquid water beneath the surface The Martian polar caps expand in winter as a thin layer of frozen carbon dioxide dry ice is deposited 39om the atmosphere V quotmainstay it nniggdawr mmrmus North polar ice cap frozen cc2 on top amazen water Vennquotibundinuolwilulhymual 1rmuuru DIAS storm Earth and Mars began with similar Clouds Above Mars Mountains atmospheres that evolved very differen ly Olympus Mons Mars s primurdiai atmusphere may have been thicker and Warmerthan the presentrday atmusphere itrs unciearvvhether rt cuntained Enuugh earpph diuxide and Waterrzapurtu suppurt a grEEDnnhuhuESE ffect that mm volcanoes e p eseht Martrah atmusphere rs umpused mustiy pr earpph diuxi e The atmpspherre pressure an the surface rs lessthan 1 that ufthe Earth and shuvvs seasunalvariatiuns as e r diuxide freezes ante and evapuratesfrumthe mi The heavily cratered southern highlands are older and about 5 km hIgher in elevation than the smooth northern lowlands The origin ofthis crustal dichotomy is not completely understood Outline for 07 November Tuesday Recap Moon Mercury Venus Earth s Atmosphere mum unnnrnnwnmnru r 421 f39 quotquot lt it mm a mm 7 nntmnl mannrnltmun Mars Atmosphere w t t nun 9 but 1mmquot Wm wwwrmm The Martian atmosphere changes dramatically with the seasons Great dust storms sometimes blanket Mars Finegrained dust in its atmosphere gives the Martian sky a pinkishorange ti t Seasonal winds blow dust across the face of Mars covering and uncovering the underlying surface material and causing seasonal color changes June 262001 ust storms begin near the northern polarta and near Hellas Planitia September 4 2001 A planemide dust storm n cures the entire surface otthe planet httpllwww2d playcomlorbtlorbtswf in classwe discussedlhe capture lheuvy mum Muun lsaid that capture is dynamically unlikely Tvylhisgamelhal simulateslhe dynamics ulan mm and liylu pullhe mm m mm around mm p anels it is nm su eas E i one that the muuns at Mars are lhuughllu have been mm h 7 7 More uncapulve httpvawwmdu may lheuN K w ucav anMuummmeanhmuuncammumuw hlml e Not in lecture notes posted yesterday Wll post link on web page Outline for 09 November Thursday Jupiter and Saturn Orbit Surface Atmosphere a s 07 Jun Key Words liquid metallic hydrogen noble gases nonthermal ra iation thermal radiation oblate oblateness p asma synchrotron radiation tidal force It is hard to see mummy Hm mm m V 1mm uIImu lupim Data Video On Jupiter 10 minutes The Complete Cosmos Jupinerand Saturn Probing the Planets Johnson Center DVD QB 442066 2003 disc 4 On reserve in Johnson Center Library Outline for 09 November Thursday Jupiter and Saturn Orbit Sur ce Atmosphere Greale sram elungminn Greats wenem exongmzon Inferior onjundinn A planet s synodic period is measured with respect to the Earth and the Sun for example from opposition to the next inferior nailunion 2 Periods Rotational Measured with respect Orbltal to something that is not Sidereal rotating or orbiting Synodic Not in lecture notes posted yesterday Orbit http llearning n deduorbitalorbitalsswf Questionquot Which is longer Jupiter s synodic or orbital period Which is longer Jupiter s synodic or Saturn s synodic period Guess Jupiter s and Satum s synodic period Will post on web page as separate pdf Question Which is longer Jupiter s synodic or orbital period orbital Which is longer Jupiter s synodic or Saturn s synodic period Jupiter s Guess Jupiter s and Saturn s synodic period A little longer than Earth s orbital period p a planet39s semimajor axis in AU Kepler s Third Law Semlmaloraxls Semimajoraxis p2 as planet39s sidereal period in years Long orbital periods of Jupiter and aturn cause favorable viewing times to shift Outl Jupiter Orbit Sum Atmosph ere ine for 09 November Thursday ce How to get Oblate hoop Will post on web page as separate pdf What happens to ornaments hoop What happens to ornaments e spun What happens to ornaments e spun What happens to ornaments What happens to ornaments The fanherawayfrumthe axls the rnere thruvvn nut rt gets The oblateness of Jupiter and Saturn reveals their rocky cores Jupiter prubably has a murky cure several nnes rnure rnasswe than the Ear h Theeurer surmunueu bya layer at hquru H225 Water ammuma methane and assumated urnpuunus on tap at hrs rs a layer at hehurn u 4 m m was 471quot Emmaan ur urmnary hydrugen and r e mm Saturn s rnternat structure rs snnnartu that ufJuplter but rts cure makes up a largerfractmn er rts vulume anu rts hquru rnetaure hydmgen mantle rs shahuwer han that ufJuplter WP tumquot Metallic hydrogen inside Jupiter and Saturn endows the planets with strong m runquot in anquot Jupiter and Saturn have strung rnagnetre elds created by eurrents m the metallic hydrugen layer Juprter s huge rna netuthere cuntams a vast current sheet at eteetneauye arge partrees Saturn s magnetm el extensive than Juprter s Jupiter and Saturn have extensive magnetospheres TheJuwan magneluspheve encluses a luwrdensllyplasma at charged pameres The magneluspheve ensts m a ueheate balance between pressuresnernthe plas rna andlmmlhe sulavwmd draslmall OUtlme for 02 November Video On Mercury10 minutes Thursday Mercury Venus The Complete Cosmos Home Star The un the Planets and Mercury Johnson Center DVD QB 442C66 2003 disc 2 If you want to view this please do not check out Instead view it in the library so other students may see it Outline for 02 November Interesting facts Thursday Mariner2visitedin1962 Mercury Venus Venus Express recently arrived Video On Venus 10 minutes Key Terms The Complete Cosmos Venus and Mars equilibrium resurfacing hypothesis Earth s Sisters Johnson Center DVD QB 442C66 2003 disc global catastrophe hypothesis prograde rotation If you want to view this please do not t d t che out Instead view it in the library so re rogra e m al other students may see it w n away greenh ouse effect Guiding Questions 1What makes Venus such a brilliant morning star or evening star 2What is strange about the rotation of Venus 3 In what ways does Venus s atmosphere differ radically from our own 4 01 01 Guiding Questions Why do astronomers suspect that there are active volcanoes on Venus Why is there almost no water on Venus today Why do astronomers think that water was once very common on Venus Does Venus have the same kind of active surface geology as the Earth It is hard to see hiercury V eastern clor tion Mercury39s rbit Mercury at greatest western elongation Ea rlh s orbit Venus at greatest eastern elongation Venus at greatest stem elongation 39 Venus39s arbil Venus s rotation is slow and retrograde retro a mng rumor lb mgndelunlian Noname rotation Draw ball and arrow at A B C D First rotate 0375 of a full turn position in orbit 884 22 days to get to A Mercury s orbital period is 88 days Mercury s rotation period is 586 days 2258 0375 C 1125 turns 0375 of a turn A 075 of a full turn 15 turns 884 22 days to get to A Mercury s orbital period is 88 days synchronous rotation Draw ball and arrow at A B C D 884 22 days to get to A Mercury s orbital period is 88 days 2258 0375 Mercury s rotation period is 58 days Mercury s rotation period is 58 days Draw ball and arrow How long is Venus s day atA B C D Venus s orbital period is 224 days Venus s rotation period is 243 days retrograde How long is Venus s day Draw ball and arrow a r retrograde clockwise rotation Takes about 60 days to get to A Takes about 60 days to rotate 90 degrees on axis Venus s orbital period is 224 da s Venus s rotation period is 243 days retrograde R How long is Venus s day Ven Ven Draw ball and arrow at A B C D Takes about 60 days to get to A Takes about 60 days to rotate 90 degrees on axis us s orbital period is 224 da s us s rotation period is 243 d ys retrograde R Draw ball and arrow at A B C D How long is Venus s day Takes about 120 days to get to A Takes about 120 days to rotate 180 degrees on axi Venus s orbital period is 224 da s Venus s rotation period is 243 days retrograde R The climate on Venus followed a different evolutionary path from that on Earth Venus s high temperature is caused by the greenhouse effect as the dense carbon dioxide atmosphere traps and retains energy from sunlight The early atmosphere of Venus contained substantial amounts of water va or This caused a runaway greenhouse effect that evaporated Venus s oceans and drove carbon dioxide out of the rocks and into the atmosphere The climate on Venus followed a different evolutionary path from that on Earth Almost all ofthe water vapor was eventually lost by the action of ultraviolet radiation on the upper atmosphere The Earth has roughly as much carbon dioxide as Venus but it has been dissolved in the Earth s oceans and chemically bound into its rocks Runaway Greenhouse Effect Volcanic eruptions are probably responsible for Venus s clouds Venus39s clouds consist of droplets o concentrated sulfuric acid Active volcanoes on enus may be a continual source of this sulfurous material m Maniquot 1xofcu mi 1 snnngma maso 1M wltanm dlswtwe In mum Exobs wlndsamam ul nunpound m m Islhudlmenmy mm m avenIullynlbdu ed g r a Eanh n0 0 and soIL are mydm 2min m Mun matqu n amampquot gtAlmasphem ohm Itmwuhem 35maxonnas mummym mmmqm 5a mug ed mso IIullwuaxldl hum valannu lnwrvm nluum n lauds nv WEN mummdmumwu my on sum mum lvllodaduplnlnlnenlx MVenusHz zandSozaraNOYruyxlul The surface of Venus shows no evidence of plate tectonics The surface ofVenus is surprisingly at mostly covered with gently rolling hills There are a few major highlands and several large volcanoes The surface ofVenus shows no evidence ofthe motion oflarge crustal plates which plays a major role in shaping the Earth s rface l 1 mldncean ri dges large plates New an ac ted at midKean ridges and returned to the huntquot a subduction zones Eanh The mm is uni and right and so an move in a Outline for 03 October Tuesday Questions about blackbody curves 20 minutes Optics and Telescopes Chapter 6 of text 55 minutes Group Question How could you measure these curves experimentally mm ma Something is Fishy In lecture and in the book no Can this gure help us explain Som ewhat flat here Wavelenglh lnm gt Can this gure help us explain Therefore The name you give a color depends on a somewhat complicated combination of wavelength intensities What we call white is not a perfect mixture of photons of the visible spectrum V39sliblilllght The Sun does not emit quot radiation with intensities that follow a blackbody exactly Blackbody curve at 5800 K Sun s intensity curve intensity gt 139 l I 0 500 1000 00 3000 Wavelength nm gt 025 020 mg 2 Solar irradiation curve Outside atmosphere s Solar irradiation curve at sea iecvei 5 ms Curve ror blackbody at 5900 ilt a o 03 z E a E 0 i0 T U n a 0 m a 081012141618202224 26 28 30 30 Wavelength pm So what color is the sun in space Solid green square So what color is the sun in space Add a little green to white background by making solid green square mostly transparent So what color is the sun in space httpcasacoloradoeduajshcolourTspec mhtm Left Right side is side is should be a white little pinker Online Quiz 7 If an object is a perfect blackbody then it emits no energy it emits energy only at certain welldefined wavelengths called spectral lines it emits energy with a continuous distribution that peaks at a certain wavelength dependent upon temperature Online Quiz 7 If an object is a perfect blackbody then it emits no energy it emits energy only at certain wellde ned wavelengths called spectral lines it emits energy with a continuous distribution that peaks at a certain wavelength dependent upon temperature Online Quiz 8 A perfect blackbody is socalled by scientists because t characteristic spectrum of radiation wh intensity as a function of wavelength depends only on its temperature it absorbs all energyfalling upon it and emits no energy at all hence its n me the shape ofthe spectrum of energy emitted by it has a xed shape independent oftemperature and only the emitted intensity at each wavelength changes with the blackbows temperature i absorbs all energyfalling upon it and emits a as Online Q B A perfect blackbody is socalled by scientists because it absorbs all energy falling upon it and emits a characteristic spectrum of radiation whose intensity as a function of wavelength depends only on its temperature it absorbs all energy falling upon it and emits no energy at all hence its n me the shape ofthe spectrum of energy emitted by it has a xed shape independent oftemperature and only the emitted intensity at each wavelength changes with the blackbody39s temperature Online Quiz 17n a beam of radiation from a blackbody the this beam how do the numbers of photons per second at each ofthese wavelengths comp r 7 There will be more UV photons than IR hotons There will be equal numbers of photons at each ofthese wavelengths There will be more IR photons than UV it Online QUIZ E 17n a beam of radiation from a blackbodly the 1 amounts of energy per second at an u raviole wavelength UV of 300 nm and at an infrared IR wavelen th of 800 nm are found to be equal Inthis eam how do the nu s mbers of photons per second at each 0 wavelengths compare There will than IR ph lR phutuns have less Energy per phutun There win Ne mare ufthem each ofthe There will be more IR 800 nm photons than UV 300 nm photons Outline for 03 October Tuesday Questions about blackbody curves Optics and Telescopes Chapter 6 of text Key Words refractionre ection convergingdiverging lens focal point angular resolution magnification chromatic aberration Key Questions Why are there so many telescopes in Hawaii Why is our best most famous telescope orbiting Earth and not in Hawaii What is the difference between optical and digital magni cation zoom How and when but not why does light and other forms of electromagnetic radiation bend How does a telescope work What is the difference between magni cation dquot M powel side note What is the difference between optical and digital zoom 10x Optical 10x Dlgllal side note What is the difference between optical and digital zoom Same amount of information Original 1nx Optical 10x Dlglal Practical note What is the difference between optical and digital zoom Much more information detail iux Digilai Therefore You can create a digital zoom effect by taking a digital picture and expanding it with photoshop etc You can t squeeze out more detail from the image that is increase the optical resolution contrary to what you see on Principle 1 Light rays from distant object are nearly Can explain lots about para 6 telescopes and other devices with only three optics principles nimm lighl source llll zssmmiy parzllll light my Principle 1 Light rays from distant object are nearly para e Principle 2 Light re ects off a at mirror in the same way a basket ball would bounce on the oor angle ofincidence i angle of re ection r Distant light source Collector l ll Esxlnlillly mllel Iialu my Principle 3 prep What happens a b or c Axleandwhad39mm I ycarnrwngnn m n hj ch mm H x x What happens a b or c an aside Something is Fishy uund iii lexlbuuks uri pmsics and a YDHDW Vuuwill ndlnisanaluw uiuiis mi maicmng suiuisisu What Vuu mm min is a PWslcalExplanallunulnuwlnEWnEElstnaE llkEllEM This is an anaiugi Mal is ussmi iui lEmEmbEllVVE Wm Wei iigm bendsWnen guingiium uiis maisiiai in a usnssi maisnai ll dues rim EXPlaln an ii is su impunam lnal axle dues rim bend ui ENE an expiaiiaiiuiiiiiai useslne MVE ui panicis piciuis uiiigm Principle 3 dllEElan mmai Luwindexl g iaiii Principle 33 uiismiun mmai LuwindeXIEQ iaii Principle 3b uppusile dllEElan Luwindexl g iaiii Principle 3c m is miimm WWW Yheseanvlesaiemual o What happens to each beam zoom box zoom box contents quot93W quot3 When zoom box contents nearly flat When zoom zoomed What happens zoom box contents zoom box The Lines Converge zoom box contents But you said different colors bend different amount 7 seem all an mun 700 um Pvism bleak gm Into Iu munm How I remember red bends less How my optometrist remembers almaspherascanevsbluelight 1 mule enemvelynlan red llght Red light be d5 ewhen you Ionkthmugh WW 3 me k slice of amaspheva m the s uquot Red light has little energy compared b Why the suing Sun looks red But you said different colors bend different Yourturn Now we can explain how an eye works how an eye works Light from a distant object how an eye works Light from Sun how an eye works Focal plane of eyepiece I Now we can explain how telescopes work Light from a distant obj Objectwa lens Focal length Focal plane of eyepiece oi eyepiece lt Eyepiue lens magn iesthe image or an sier viewing Objective rorms an Image in the roar plane J I Fatal lengm of abjeuivn g Telescope principles Magni cation is ratio ofhow big object looks to naked eye angular diameter to how big it look through telescope yz D 10 E39 Magni cation is 1005 20x Telescope principles Although telescopes magnify their primary purpose is to Distant llghl source Collector Enemaquot ralel h lig trys Question ch more energy does a1 cm radius circular collector absorb than a 4 cm radius collector Distant llgln wince 6x Need more in Collector Essanliall gsvallel light my Question ch more energy does a 1 cm radius circular collector absorb than a 4 cm radius collec or Same 2x 4x 16x Need more info Area ofcircle is proportional to r2 A1 is proportional to 1 cm21 cm2 A2 is proportional to 4 cm2 16 cm2 Reflecting telescope Previously I described a refracting telescope The principles of reflection can be used to build a telescope too Concave mirror Focal p nt Incoming parallel light rays from a distant object Focal length Problem head blocks light Concavemirror Final pn parallellighl ad39 islam nhjen Focal lengur olutions l l ll Sunlile Sumndlvy Mirror Mum mm Independent reading Read Chapter 6 and be able to answer What is a prism spectrograph Wnat does it measure and what principles does it use What is a radio telescope What does it measure and what principles does it use and the following multiple choice questions Arelledingtelescupe used at pnmereeus dues nut su errre Asphericalminursullerslrumsphericalaberratiunbecause A 012 i The MD ranges ulelectrumagnetic radiatiun rerwnren Earth s a m enremaire aberration because A regardless areeier allwavelenglhs Diling are reflected bythe same amuunt E ine aiumrnum mating en ine mrrrer absuvbs lighllrum allwavelenglhs excepting range er rnieresne ine asirenemer c ine lens is pe ectlgVurmw 5 all eeiers ullighllravellhmu n ine iens alung X2 same ine light nas in pa n D assed thvuugh en y ene iens Ans Seeiren 572 siarirgni is distuned byturbulence rn ine Earth s atmusphere e mrrrer sags under its ewnwergni dismmng ine image c urrrereni panser emrrrerreeusineirgniaiurrrereniursianeesrremine mrrrer D urwereni eeiers are reeuseuaiunrereni ursianeesrremine mrrrer Ans c Sectiun 572 Aradiutelescupe isverysimilartu arerraeungepireaiieieseepe is verysimilartu a re ecting upticaltelescupe is cumpletely urrrereni rn designlrumanyupticaltelescupe eemiernesmarerreaiureseruein rerraeunganurerieeungepireaiieieseepes Ans a Seeiren are tmusphere is reasunablytvanspavem are A UVand radiu Waves c Xra sandvisibleradialiun BJVisibleandlarinlraredradialiun D visibeandradiuradialiun Ans D Sectiun 577 Review Questions For Topics Covered in Lecture At what distance 39om the objective lens in other qu estions a refracting telescope is the image formed ie where would the photographic lm or electronic detector be placed A immediately behind the lens to collect the most light B its diameter 0 its focal length Dtwice its focal length Ans 0 Section 61 Thursday Outline for 24 October Return Exam 2 and Discuss 20 minutes The Moon Exam 2 Average was B 49 questions Density massNolume Volume r3 If radius doubles Volume goes up by factor of 23 B and so density goes down by a factor of B as nd its mass was the same its density would be gt 1 free question What is your exam form or Dquot Question 13 55 minutes gt Correct answer Is gt Was mlsgraded and should not have been t e ex m anywa gt 1 added to all exams whether or not you got it right or wrong Exam 2 Question 23 lfthe radius of Earth w twice as much a Question 2832 A Question 44 What is the solar wind Question 48 What advantage does a telescope on the Moon have over one in Hawaii Less in uence of Light pollution It is only closer to the stars by a small amount Question 50 The greenhouse effect is the Outline for 24 October Thursday Return Exam 2 and Discuss 20 minutes The Moon 55 minutes Guiding Question 1 How did the Moon form Key Words WW capturetheury mare plummaria center uf mass W curcreatmntheury cuihsiunai ejectmntheury crater muunquake w m ufmemuun synchrunuusrutatiun ssiun theury terminatur 39 impactcrater vuiatiie eiement Key Words W capturetheury mare plummaria center uf mass W curcreatm ntheury uihsiunaiejectmntheury Wmmme crater farside ufthe Mann Wmi synchrunuusrutatiun fissiuntheury Emmett vuiatiie eiement Key Words WW capture theory mare plummama W curcreatm theory W unsmna ejectmntheury mmmeae crater synchronousrutatmn 39 SS DM EDW terrmnatur mm W 39 mpactcrater vmame e ement The Moon39s rotation always keeps the same face toward the Earth due to synchronous rotation Ihh Mm m m mm In an m Mann dons mink we mill 5 all shins oi in Moon and we we only m cm cl the Mac hymnxenth Allen mam quotmam lwmhk mm mmm am 39 Observations How did the moon form How did the moon form Observations Theory The rnaria formed a erthe surrounding lightcolored terrain so they have not been exposed to meteon39 c Vlnuallv fl mbardmem for as long and have fewer craters war W E S were caused by space u b e rls Striking the surface Muunquakes are rare and Weak 4 Lunar rocks reveal a geologic history quite unlike that of Earth a small core beneath athick mantle Solid lithosphere The anunhusmc crust s E bllllDWEarS nmuuim Tumulwn 39 e Plastic woo km zsthenosphere lnhnxuhambudmenldurhgmrllm onmanna nermumra Key W0 rd S W W mare plural marla center Elf mass W W Mnemosyneu y W crate r mini Fuymauonulmn lmmlilgnmwausnur lhenMallheiulennbnm dummy 0 farSldEWHhEll n synchrunuusrutallun flssluntheur lermmamr Ram olemenmking karma umugnumorummuunng mamasumanym Wartth vulatlle Element e llereaeei o 3 z I Time wave uresenl billions ol yearsl Course Review Please comment on Textbook and course content Lecture and lecture content Outline for 05 December Tuesday Discuss Final Neptune Uranus and Pluto Asteroids and Comets Final 7 anamm 153m Decembele Tuesday 7 m WW Abuut mu multiple enm 2 questions 7 new In an enamels a a n new EU aneemneina Page nun Hans a win about equal wage at naena m eam Huw many questinnswill be ine same aaine tunes on previous any Duyuuneedtutakethelmaw 7 my na We m be ine aveaee m m nenea nee peeenaee was among Hans a amine ma W percentage was in mm pageinaiislmkedinnninebminm m ine we a 7 mm na nemeniaee am we m be were u vnu missed one exam vnuv nal grade will be We avemge a ne invee exams new 0 7 mo 5 Exam Preparation Work problems from previous exams Work problems in course notes N me an Notes Outline for 05 December Tuesday Discuss Final Neptune Uranus and Pluto Asteroids and Comets iahlwvi Illunis llala minin i Npplunv uld Uranus and Neptune each have a system ofthin dark rings hlheuw ghuaEuh m n um um when mum mum 1er mum r Neptune and Uranus should not r Explain Uranus and Neptune contain a higher proportion than Jupiter and Saturn Nevlun Both Uranus and Neptune may have a rocky core surrounded by a mantie ofwaterand ammoma Eiecinc currents m the manties may generate the magnetic eids ofthe Diane E Bizarro tilt on Uranus n twain mm mm N Summevat 710th we Saulh xuuthcm mu F Bizarro Magnetic Axis The magneti elds of both Pluto and its moon Charon may be typical of a thousand icy objects that orbit far from the Sun V my mum mm new Piutu vvas mseeveree after a iung search Piutu and its mean Charm muve tugether m a mgmy eihpticai emu steepiy mined in the piane ufthe echptu They are the uniy Wurids m the suiar system nutyet visited by spacecraft Guiding Questions 1How did Uranus and Neptune come to be discovered 2What gives Uranus its distinctive greenish ue color 3Why are the clouds on Neptune so much more visible than those on Uranus 4Are Uranus and Neptune merely smaller versions ofJupiter and Saturn 5What is so unusual about the magnetic elds ofUranus and Neptune Guiding Questions 6 Do the moons ofUranus show any signs of geologic activity 7 Are there other planets beyond Pluto Outline for 05 December Tuesday Discuss Final Neptune Uranus and Pluto Asteroids and Comets Laws TitiusBode Law From one planet to the next the semimajor axis ofthe orbit increases by a factor ofbetween approximately 14 and quot A search for a planet between Mars and Jupiter led to the discovery of asterOIds strunurne Sfl 51 di re he steruids While searchingf ra Mars and Jupiter More magic ratios Jupiter s graVIty helped shape the asteroid belt Even tod The resulting gaps called Kirkwood ur at simple fractions of Jupiter39s orbital um Wm ma Jupiter s gravity also captures asteroids in two locations called Lagrangian points along upiter s orbit mm mm y napvenauwomm lagunge pnlnuh the wmbined gravitational Inrnxallhtsunlnd Jupiler 9mg Point I Asteroids are found outside the asteroid Terminology belt Asteroid minor planet or planetoid Orbit un Generally biggerthan Meteoroidquot Meteoroid A Suild ebreetmevrrrg m interplanetary spaee era size new era ly smaller than an astermd and eensreeramy largerthan an atum ur muleeule shooing starquot Occurs when Meteoroid enters the Earth s atmosphere e astermds called nearrEarth ubjeets muve rrr Meteorite Meteorthat survived descent eurptrear erarts that truss the erarts er Mars and Earth through almost Ere ltsueh arr astermd strikesthe Earth rtrerrns an rrnpaet cratervvhuse diameter depends un buth the mass and the speed at the astermd What are chances of hitting asteroid as you pass through asteroid belt V a Comets Two sources of comets Originate from a belt beyond Pluto or a Kuiper belt source ofJupiter famin vast cloud in interstellar space comets Dusty chunk of ice that partially vaporizes Oort Cloud as it passes nearthe Sun or from a vast cloud in near interstellar space Nuiper hel objects The om emu eumams when at Emmet nudet m a sphermal msmbuuen that Extends nut in mm AU frum the Sun mtermemate permd and lungrpermd cumets are thuughttu engmate m the cm exam 5 yetnu emeets m the Ourtcluud have been detected mreeuy Pluto39s or mum mmwewm The Kuiper 21T 32 WWW belt lies in the mmmmn m in m 0 MW plane ofthe J p I F m ecliptic at distances between 30 xmemum ammmmm thousands of me um um magnum yumquotmu3ummueWem comet nucleI Kuiper Belt A comet is a dusty chunk of ice that partially vaporizes as it passes near the Sun Aco t39 omu39s orbit in a highl elliptical orbit about the Sun its in nucleus develops a luminous coma surrounded by a vast hydrogen envelope Dunuall gt gt4 w en eralngpe 6 I Nucleus m 3 lenm q
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