- 28.1: LO1 Outline the processes that led to life on Earth. Why islife dif...
- 28.2: LO2 What is chemical evolution? What are the basicingredients from ...
- 28.3: What is the Urey-Miller experiment? What importantorganic molecules...
- 28.4: Why do some scientists think life might have originated inspace?
- 28.5: POS How do we know anything at all about the earlyepisodes of life ...
- 28.6: What is the role of language in cultural evolution?
- 28.7: LO3 Wherebesides Earth and the planet Marsmightwe hope to find sign...
- 28.8: POS Do we know whether Mars ever had life at any timeduring its pas...
- 28.9: POS What is generally meant by life as we know it? Whatother forms ...
- 28.10: LO4 How many of the factors in the Drake equation areknown with any...
- 28.11: What factors determine the suitability of a star as the parentof a ...
- 28.12: What is the relationship between the average lifetime ofgalactic ci...
- 28.13: How would Earth appear at radio wavelengths toextraterrestrial astr...
- 28.14: LO5 POS What is the water hole? What advantagesdoes it offer for in...
- 28.15: If you were designing a SETI experiment, what parts of thesky would...
Solutions for Chapter 28: Life in the Universe
Full solutions for Astronomy Today | 8th Edition
A star whose brightness varies periodically because it expands and contracts. A type of pulsating star.
Cone of depression
A cone-shaped depression in the water table immediately surrounding a well.
A layer of coarse pebbles and gravel created when wind removed the finer material.
A belt of low pressure lying near the equator and between the subtropical highs.
An eruption in which lava is extruded from narrow fractures or cracks in the crust.
A bent rock layer or series of layers that were originally horizontal and subsequently deformed.
The time required for one-half of the atoms of a radioactive substance to decay.
Meandering channel that flows in a steep, narrow valley. They form either when an area is uplifted or when base level drops.
A system for classifying climates devised by Wladimir Köppen that is based on mean monthly and annual values of temperature and precipitation.
The process, generally cementation and/or compaction, of converting sediments to solid rock.
The elevated landforms that parallel some streams and act to confine their waters, except during floodstage.
Negative feedback mechanism
A feedback mechanism that tends to maintain a system as it is—that is, maintain the status quo.
A volcanic glass of felsic composition.
A span on the geologic time scale between the eons of the Precambrian and Mesozoic era from about 540 million to 248 million years ago.
The distance at which an object would have a parallax angle of 1 second of arc (3.26 lightyears).
Plane of the ecliptic
The imaginary plane that connects Earth’s orbit with the celestial sphere.
A lake formed during a period of increased rainfall. During the Pleistocene epoch this occurred in some nonglaciated regions during periods of ice advance elsewhere.
A scale of earthquake magnitude based on the motion of a seismograph.
The relative proportions of clay, silt, and sand in a soil. Texture strongly influences the soil’s ability to retain and transmit water and air.
A pluton similar to but smaller than a batholith.