Choose the best answer to the following.

Problem 22SEQ Explain answer clearly, using complete sentence and proper essay structure if needed. An asterisk (*) designates a quantitative problem, for which you should show all your work. *Galactic Rotation. Our solar system is located about 28,000 light-years from the galactic center and orbits the center once every 230 million years. How fast are we traveling around the galaxy, in km/hr?

Problem 4QQ Choose the best answer to the following. Explain your reasoning with one more complete sentence. The star Antares is 604 light-years away. If it explodes tonight, (a) we’ll know because it will be brighter than the full Moon. (b) we’ll know because debris from the explosion will rain down on us from space. (c) we won’t know about it for another 604 years.

Problem 2QQ Choose the best answer to the following. Explain your reasoning with one more complete sentence. An astronomical unit is (a) any planet’s average distance from the Sun. (b) Earth’s average distance from the Sun. (c) any large astronomical distance.

Problem 5QQ Choose the best answer to the following. Explain your reasoning with one more complete sentence. Could we see a galaxy that is 20 billion light-years away? (a) Yes, if we had a big enough telescope. (b) No, because it would be beyond the bounds of our observable universe. (c) No, because a galaxy could not possibly be that far away.

Problem 1QQ Choose the best answer to the following. Explain your reasoning with one more complete sentence. Which of the following correctly lists our “cosmic address” from smallest to largest? (a) Earth, solar system, Milky Way Galaxy, Local Group, Local Supercluster, universe (b) Earth, solar system, Local Group, Local Supercluster, Milky Way Galaxy, universe (c) Earth, Milky Way Galaxy, solar system, Local Group, Local Supercluster, universe

Problem 3QQ Choose the best answer to the following. Explain your reasoning with one more complete sentence. A light-year is (a) about 10 trillion kilometers. (b) the time it takes light to reach the nearest star. (c) the time it takes light to travel around the Sun.

Problem 6QQ Choose the best answer to the following. Explain your reasoning with one more complete sentence. If we represent the solar system on a scale that allows us to walk from the Sun to Pluto in a few minutes, then (a) the planets are the size of basketballs and the nearest stars are a few miles away. (b) the planets are marble size or smaller and the nearest stars are thousands of miles away. (c) the planets are microscopic and the stars are millions of miles away.

Problem 10QQ Choose the best answer to the following. Explain your reasoning with one more complete sentence. We are “star stuff” in the sense that (a) we are made of elements that were produced in stars. (b) our bodies have the same chemical composition as stars. (c) we are born, live, and die, just like stars.

Problem 7QQ Choose the best answer to the following. Explain your reasoning with one more complete sentence. The number of stars in the Milky Way Galaxy is roughly (a) 100,000. (b) 100 million. (c) 100 billion.

Problem 8QQ Choose the best answer to the following. Explain your reasoning with one more complete sentence. When we say the universe is expanding, we mean that (a) everything in the universe is growing in size. (b) the average distance between galaxies is growing with time. (c) the number of stars in the universe is growing with time.

Problem 9QQ Choose the best answer to the following. Explain your reasoning with one more complete sentence. The Big Bang is the name astronomers give to (a) the explosion that occurs when a star dies. (b) the largest explosion ever observed. (c) the birth of the universe.

Problem 11QQ Choose the best answer to the following. Explain your reasoning with one more complete sentence. The age of our solar system is about (a) of the age of the universe. (b) of the age of the universe, (c) the same as the age of the universe.

Problem 12QQ Choose the best answer to the following. Explain your reasoning with one more complete sentence. The event that triggered the change in Pluto’s status from planet to dwarf planet was the discovery that (a) it is smaller than the planet Mercury. (b) it has a comet-like composition of ice and rock. (c) it is not the largest object in its region of the solar system.

Problem 14SEQ Alien Technology. Some people believe that Earth is being visited by aliens from other star systems. If this is true, how would the alien technology compare to our own? Using ideas of scale introduced in this chapter, write one to two paragraphs to give a sense of the technological difference.

Problem 13SEQ Explain answer clearly, using complete sentence and proper essay structure if needed. Our Cosmic Origins. Write one to three paragraphs summarizing why we could not be here if the universe did not contain both stars and galaxies.

Problem 16SEQ The Value of Classification. Section 1.3 discussed difficulties that can arise with attempts to define scientific classifications precisely, such as those that occur with the term planet. Make a bullet list of pros and cons (at least three of each) to having classification schemes. Then write a one-paragraph summary stating your opinion of the value (or lack of value) of scientific classification.

Problem 15SEQ Explain answer clearly, using complete sentence and proper essay structure if needed. Looking for Evidence. This chapter discussed the scientific story of the universe but not the evidence that backs it up. Choose one idea from this chapter—such as the idea that there are billions of galaxies, that the universe was born in the Big Bang, or that we are “star stuff”—and briefly discuss the type of evidence you would like to see before accepting the idea. (Hint: You can look ahead in the book to see the evidence presented in later chapters.)

Problem 18SEQ Explain answer clearly, using complete sentence and proper essay structure if needed. An asterisk (*) designates a quantitative problem, for which you should show all your work. *Light-Minute. Just as a light-year is the distance that light can travel in 1 year, a light-minute is the distance that-light can travel in 1 minute. What is a light-minute in kilometers?

Problem 17SEQ Explain answer clearly, using complete sentence and proper essay structure if needed. The Cosmic Perspective. Write a one-page essay describing how the ideas presented in this chapter affect your perspectives on your own life and on human civilization.

Problem 19SEQ Explain answer clearly, using complete sentence and proper essay structure if needed. An asterisk (*) designates a quantitative problem, for which you should show all your work. *Sunlight. Use the speed of light and the Earth-Sun distance of 1 AU to calculate how long it takes light to travel from the Sun to Earth.

Problem 20SEQ Explain answer clearly, using complete sentence and proper essay structure if needed. An asterisk (*) designates a quantitative problem, for which you should show all your work. *Cosmic Calendar. The cosmic calendar condenses the 14-billion-year history of the universe into 1 year. How long does 1 second represent on the cosmic calendar?

Problem 21SEQ Explain answer clearly, using complete sentence and proper essay structure if needed. An asterisk (*) designates a quantitative problem, for which you should show all your work. *Saturn vs. the Milky Way. Photos of Saturn with its rings can look so similar to photos of galaxies that children often think they are similar objects, but of course galaxies are far larger. About how many times larger in diameter is the Milky Way Galaxy than Saturn’s rings? (Data: Saturn’s rings are 270,000 km in diameter; the Milky Way is 100,000 light-years in diameter.)