Frontmatter Introduction
About the Authors
Brief Contents
Contents
A Letter From the Authors
Preface
Chapter Introduction
1-1 Astronomy is both an ancient cultural practice and a cutting-edge science
1-2 The stars are grouped by constellations
1-3 All of the observed celestial motions can be described if our planet earth spins once each day while it orbits around our sun each year
1-4 The Sun appears to change position over the day and throughout the year, and these changes result in Earth’s seasons
1-5 The Moon appears to change its position in the sky hourly and its phase throughout each month
1-6 Eclipses occur only during rarely observed events when our sun, moon, and earth are perfectly aligned
Key Ideas and Terms
Questions
Answers
Chapter Introduction
2-1 Light travels through empty space at a speed of nearly 300,000 km/s
2-2 Glowing objects, like stars, emit an entire spectrum of light
2-3 An object’s temperature is revealed by the most intense wavelength of its spectrum of light
2-4 An object’s chemical composition is revealed by the unique pattern of its spectrum of light
2-5 An object’s motion through space is revealed by the precise wavelength positions of its spectrum of light
2-6 Telescopes use lenses, mirrors, and electronics to concentrate and capture incoming light for study
Key Ideas and Terms
Questions
Answers
Chapter Introduction
3-1 Astronomers of antiquity used observation and reasoning to develop astonishing advances in the study of astronomy
3-2 Nicolaus Copernicus devised the first comprehensive Sun-centered model
3-3 Galileo’s discoveries of moons orbiting Jupiter and the phases of Venus strongly supported a heliocentric model
3-4 Johannes Kepler proposed that planets orbit the Sun in elliptical paths, moving fastest when closest to the Sun, with the closest planets moving at the highest speeds
3-5 Isaac Newton formulated three laws relating force and motion to describe fundamental properties of physical reality
3-6 Newton’s description of gravity accounts for Kepler’s laws and explains the motions of the planets
Key Ideas and Terms
Questions
Answers
Chapter Introduction
4-1 The solar system has two broad categories of planets orbiting the Sun: terrestrial (Earthlike) and Jovian (Jupiterlike)
4-2 Seven large moons are almost as big as the inner, terrestrial planets
4-3 Spectroscopy reveals the chemical composition of the planets
4-4 Small chunks of rock and ice also orbit the Sun: asteroids, trans-Neptunian objects, and comets
4-5 The Sun and planets formed from a rotating solar nebula
4-6 The planets formed by countless collisions of dust, rocks, and gas in the region surrounding our young Sun
4-7 Understanding how our planets formed around the Sun suggests that planets around other stars are common
Key Ideas and Terms
Questions
Answers
Chapter Introduction
5-1 Most of Earth’s surface is covered with flowing water that radically changes the landscape
5-2 Earth is surrounded by a thin, multilayered envelope of gas that has changed since life became prominent
5-3 Volcanoes and earthquakes reveal energy from a molten interior driving Earth’s surface to shift positions
5-4 Earth’s magnetic field emanating from its spinning, molten interior creates a protective shield from the Sun’s harmful radiation
5-5 A rapidly growing population is altering our planetary habitat
Key Ideas and Terms
Questions
Answers
Chapter Introduction
6-1 Comparing terrestrial planets and moons shows distinct similarities and dramatic differences in appearance
6-2 Many terrestrial world surfaces are dominated by impact craters revealing the age of underlying processes
6-3 Tectonics and volcanism influence surface features
6-4 Atmospheres surrounding terrestrial planets vary considerably
6-5 Evidence exists for water in locations besides Earth
Key Ideas and Terms
Questions
Answers
Chapter Introduction
7-1 Dynamic atmospheres of Jupiter and Saturn change rapidly
7-2 Uranus and Neptune have seemingly quiet atmospheres
7-3 Saturn’s moon Titan and Neptune’s moon Triton exhibit unexpected atmospheres
7-4 All Jovian planet atmospheres are encircled by complex ring systems
Key Ideas and Terms
Questions
Answers
Chapter Introduction
8-1 Planets and the chemical building blocks of life are found throughout space
8-2 Europa and Mars have the potential for life to have evolved
8-3 Meteorites from Mars have been scrutinized for life-forms
8-4 The Drake equation helps scientists estimate how many civilizations may inhabit our Galaxy
8-5 Searches with space-based infrared telescopes and Earth-based radio telescopes for Earthlike planets and alien civilizations are under way
Key Ideas and Terms
Questions
Answers
Chapter Introduction
9-1 The Sun’s energy is generated by thermonuclear reactions in its core
9-2 Energy slowly moves outward from the solar interior through several processes
9-3 The Sun’s outer layers are the photosphere, chromosphere, and corona
9-4 Sunspots are low-temperature regions in the photosphere
9-5 The Sun’s magnetic field also produces other forms of solar activity and causes aurorae on Earth
Key Ideas and Terms
Questions
Answers
Chapter Introduction
10-1 Measuring the distances to nearby stars utilizes an effect called parallax
10-2 A star’s brightness can be described in terms of luminosity or magnitude
10-3 A star’s distance can be determined by comparing its luminosity and brightness
10-4 A star’s color depends on its surface temperature
10-5 The spectra of stars reveal their chemical compositions as well as surface temperatures and sizes
10-6 Stars come in a wide variety of sizes and masses
10-7 Hertzsprung-Russell (H-R) diagrams reveal the different kinds of stars
Key Ideas and Terms
Questions
Answers
Chapter Introduction
11-1 Stars form from the gravitational collapse of immense clouds of interstellar gas and dust
11-2 Most stars shine throughout their lives by converting hydrogen into helium through nuclear fusion
11-3 Careful observations of star clusters provide insight into how a star’s mass influences how stars change over time
11-4 Stars slowly become red giants
11-5 Low-mass stars pulsate and eject planetary nebulae, leaving behind a white dwarf at the end of their life cycles
Key Ideas and Terms
Questions
Answers
Chapter Introduction
12-1 High-mass stars create heavy elements in their cores before violently blowing apart in supernova explosions, leaving behind remnants
12-2 Core-collapse supernovae can leave behind remnants, neutron stars, and pulsars
12-3 Black holes are created in the death throes of the most massive of stars
12-4 Black holes cannot be seen directly
12-5 White dwarfs and pulsars in close binary systems can become novae, bursters, and supernovae
Key Ideas and Terms
Questions
Answers
Chapter Introduction
13-1 The Sun is located in the disk of our Galaxy, about 25,000 light-years from the galactic center
13-2 Observations of different types of dust, gas, stars, and star clusters reveal the shape of our Galaxy
13-3 Observations of star-forming regions reveal that our Galaxy has spiral arms
13-4 Measuring the rotation of our Galaxy reveals the presence of dark matter
13-5 Spiral arms are caused by density waves that sweep around our Galaxy
13-6 Infrared and radio observations are used to probe the galactic nucleus
Key Ideas and Terms
Questions
Answers
Chapter Introduction
14-1 When galaxies were first discovered, it was not clear that they lie far beyond the Milky Way until their variable stars were carefully observed
14-2 Hubble devised a system for classifying galaxies according to their appearance
14-3 Exploding stars release similar amounts of light and their distance can be inferred by measuring their apparent brightness
14-4 Galaxies are found in clusters and superclusters
14-5 Colliding galaxies produce starbursts, spiral arms, and other spectacular phenomena
14-6 Dark matter can be inferred by observing the motions of galaxy clusters
14-7 Quasars are the ultraluminous centers of the most distant galaxies
14-8 Supermassive black holes may be the “central engines” that power active galaxies
14-9 Galaxies may have formed from the merger of smaller objects
Key Ideas and Terms
Questions
Answers
Chapter Introduction
15-1 The darkness of the night sky tells us about the nature of the universe
15-2 Our observations show us that the universe is expanding
15-3 The expanding universe emerged from a cataclysmic event called the Big Bang
15-4 The microwave radiation that fills all space is compelling evidence of a hot Big Bang
15-5 The universe was a rapidly expanding, hot, opaque plasma during its first 300,000 years and has slowly cooled
15-6 The shape of the universe indicates its matter and energy content
15-7 Observations of distant supernovae indicate that we live in an accelerating universe
Key Ideas and Terms
Questions
Answers
Appendix Introduction
Appendix 1: The Planets: Orbital Data
Appendix 2: The Planets: Physical Data
Appendix 3: Satellites of the Planets
Appendix 4: The Nearest Stars
Appendix 5: The Visually Brightest Stars
Appendix 6: Some Useful Mathematics
Appendix 7: Some Important Astronomical Quantities
Appendix 8: Some Important Physical Constants
Appendix 9: Powers-of-Ten Notation
Appendix 10: Jupiter’s Galilean Satellites Compared with the Moon, Mercury, and Mars
Index
Star Charts