Contents

Preface to the New Edition

Acknowledgments

Birth of the Universe

c. 13.7 Billion BCE Big Bang

c. 13.7 Billion BCE Recombination Era

c. 13.5 Billion BCE First Stars

c. 13.3 Billion BCE Milky Way

c. 5 Billion BCE Solar Nebula

c. 4.6 Billion BCE Violent Proto-Sun

c. 4.6 Billion BCE Birth of the Sun

c. 4.5 Billion BCE Mercury

c. 4.5 Billion BCE Venus

c. 4.5 Billion BCE Earth

c. 4.5 Billion BCE Mars

c. 4.5 Billion BCE Main Asteroid Belt

c. 4.5 Billion BCE Jupiter

c. 4.5 Billion BCE Saturn

c. 4.5 Billion BCE Uranus

c. 4.5 Billion BCE Neptune

c. 4.5 Billion BCE Pluto and the Kuiper Belt

c. 4.5 Billion BCE Birth of the Moon

c. 4.1 Billion BCE Late Heavy Bombardment

c. 3.8 Billion BCE Life on Earth

550 Million BCE Cambrian Explosion

65 Million BCE Dinosaur-Killing Impact

200,000 BCE Homo Sapiens

c. 50,000 BCE Arizona Impact

Observing the Heavens

c. 5000 BCE Birth of Cosmology

c. 3000 BCE Ancient Observatories

c. 2500 BCE Egyptian Astronomy

c. 2100 BCE Astronomy in China

c. 500 BCE Earth Is Round!

c. 400 BCE Greek Geocentrism

c. 400 BCE Western Astrology

c. 280 BCE Sun-Centered Cosmos

c. 250 BCE Eratosthenes Measures the Earth

c. 150 BCE Stellar Magnitude

c. 100 BCE First Computer

45 BCE Julian Calendar

c. 150 Ptolemy’s Almagest

185 Chinese Observe “Guest Star”

c. 500 Aryabhatiya

c. 700 Finding Easter

c. 825 Early Islamic Astronomy

c. 964 Andromeda Sighted

c. 1000 Experimental Astrophysics

c. 1000 Mayan Astronomy

1054 “Daytime Star” Observed

c. 1230 De Sphaera

c. 1260 Large Medieval Observatories

c. 1500 Early Calculus

1543 Copernicus’s De Revolutionibus

1572 Brahe’s “Nova Stella”

1582 Gregorian Calendar

1596 Mira Variables

1600 Bruno’s On the Infinite Universe and Worlds

c. 1608 First Astronomical Telescopes

1610 Galileo’s Starry Messenger

1610 Europa

1610 Ganymede

1610 Callisto

1610 Orion Nebula “Discovered”

1619 Three Laws of Planetary Motion

1639 Venus Transits the Sun

1650 Mizar-Alcor Sextuple System

1659 Saturn Has Rings

1665 Great Red Spot

1665 Globular Clusters

1671–1672 Iapetus and Rhea

1676 Speed of Light

1682 Halley’s Comet

1684 Tethys and Dione

1684 Zodiacal Light

1686 Origin of Tides

1687 Newton’s Laws of Gravity and Motion

1718 Proper Motion of Stars

1757 Celestial Navigation

1764 Planetary Nebulae

1771 Messier Catalog

1772 Lagrange Points

1781 Discovery of Uranus

1787 Titania and Oberon

1789 Enceladus

1794 Meteorites Come from Space

1795 Encke’s Comet

1814 Birth of Spectroscopy

1838 Stellar Parallax

1839 First Astrophotographs

1846 Discovery of Neptune

1846 Triton

1847 Miss Mitchell’s Comet

1848 Doppler Shift of Light

1848 Hyperion

1851 Foucault’s Pendulum

1851 Ariel and Umbriel

1857 Kirkwood Gaps

1859 Solar Flares

1859 Search for Vulcan

1862 White Dwarfs

1866 Source of the Leonid Meteors

1868 Helium

1877 Deimos

1877 Phobos

1887 End of the Ether

1893 Star Color = Star Temperature

1895 Milky Way Dark Lanes

1896 Greenhouse Effect

1896 Radioactivity

1899 Phoebe

1900 Quantum Mechanics

1901 Pickering’s “Harvard Computers”

1904 Himalia

1905 Einstein’s “Miracle Year”

1906 Jupiter’s Trojan Asteroids

1906 Mars and Its Canals

1908 Tunguska Explosion

1908 Cepheid Variables and Standard Candles

1910 Main Sequence

1918 Size of the Milky Way

1920 “Centaur” Asteroids

1924 Eddington’s Mass-Luminosity Relation

1926 Liquid-Fueled Rocketry

1927 The Milky Way Rotates

1929 Hubble’s Law

1930 Discovery of Pluto

1931 Radio Astronomy

1932 The Öpik-Oort Cloud

1933 Neutron Stars

1933 Dark Matter

1936 Elliptical Galaxies

1939 Nuclear Fusion

1945 Geosynchronous Satellites

1948 Miranda

1955 Jupiter’s Magnetic Field

1956 Neutrino Astronomy

The Space Age

1957 Sputnik 1

1958 Earth’s Radiation Belts

1958 NASA and the Deep Space Network

1959 Far Side of the Moon

1959 Spiral Galaxies

1961 First Humans in Space

1963 Arecibo Radio Telescope

1963 Quasars

1964 Cosmic Microwave Background

1965 Black Holes

1965 Hawking’s “Extreme Physics”

1966 Venera 3 Reaches Venus

1967 Pulsars

1967 Study of Extremophiles

1969 First on the Moon

1969 Second on the Moon

1969 Astronomy Goes Digital

1970 Organic Molecules in Murchison Meteorite

1970 Venera 7 Lands on Venus

1970 Lunar Robotic Sample Return

1971 Fra Mauro Formation

1971 First Mars Orbiters

1971 Roving on the Moon

1972 Lunar Highlands

1972 Last on the Moon

1973 Gamma-Ray Bursts

1973 Pioneer 10 at Jupiter

1976 Vikings on Mars

1977 Voyager “Grand Tour” Begins

1977 Uranian Rings Discovered

1978 Charon

1979 Active Volcanoes on Io

1979 Jovian Rings

1979 An Ocean on Europa?

1979 Gravitational Lensing

1979 Pioneer 11 at Saturn

1980 Cosmos: A Personal Voyage

1980, 1981 Voyager Saturn Encounters

1981 Space Shuttle

1982 Rings Around Neptune

1984 Circumstellar Disks

1986 Voyager 2 at Uranus

1987 Supernova 1987 A

1988 Light Pollution

1989 Voyager 2 at Neptune

1989 Walls of Galaxies

1990 Hubble Space Telescope

1990 Venus Mapped by Magellan

1992 Mapping the Cosmic Microwave Background

1992 First Extrasolar Planets

1992 Kuiper Belt Objects

1992 Asteroids Can Have Moons

1993 Giant Telescopes

1994 Comet SL-9 Slams into Jupiter

1994 Brown Dwarfs

1995 Planets Around Other Suns

1995 Galileo Orbits Jupiter

1996 Life on Mars?

1997 “Great Comet” Hale-Bopp

1997 253 Mathilde

1997 First Rover on Mars

1997 Mars Global Surveyor

1998 International Space Station

1998 Dark Energy

1999 Torino Impact Hazard Scale

1999 Chandra X-ray Observatory

2000 An Ocean on Ganymede?

2000 NEAR at Eros

2001 Solar Neutrino Problem

2001 Age of the Universe

2001 Genesis Catches Solar Wind

2003 Spitzer Space Telescope

2004 Spirit and Opportunity on Mars

2004–2017 Cassini Explores Saturn

2004 Stardust Encounters Wild-2

2005 Deep Impact: Tempel-1

2005 Huygens Lands on Titan

2005 Hayabusa at Itokawa

2006 Demotion of Pluto

2007 Habitable Super Earths?

2009 Kepler Mission

2010 Rosetta Flies by 21 Lutetia

2010 Comet Hartley-2

2011 MESSENGER at Mercury

2011 Dawn at Vesta

2012 Mars Science Laboratory Curiosity Rover

2013 Chelyabinsk Fireball

2015 LightSail-1

2015 Dawn at Ceres

2015 Pluto Revealed!

2016 Juno at Jupiter

2016 ExoMars Trace Gas Orbiter

2016 Gravitational Waves

2017 North American Solar Eclipse

2017 Planets around TRAPPIST-1

2018 InSight to Mars

2019 James Webb Space Telescope

Our Future

2020 Start of Mars Sample Return

~2022 Europa Clipper

2022 Jupiter Icy Moons Explorer

~2025? WFIRST

2029 Apophis Near Miss

~2035–2050 First Humans on Mars?

~2050? Breakthrough Starshot

~100 Million Sagittarius Dwarf Galaxy Collision

~1 Billion Earth’s Oceans Evaporate

~3–5 Billion Collision with Andromeda

~5–7 Billion End of the Sun

~10¹⁴ Last of the Stars

The End of Time: How Will the Universe End?

Notes and Further Reading