INTRODUCTION: THE PROJECT AND THE PLANET
1.John D. Durand, “Historical Estimates of World Population: An Evaluation,” PSC Analytical and Technical Reports, no. 10 (1974): table 2.
2.Department of Economic and Social Affairs, Population Division, The World at Six Billion (New York: United Nations Secretariat, 1999), http://www.un.org/esa/population/publications/sixbillion/sixbillion.htm.
3.Paul Mann, Lisa Gahagan, and Mark B. Gordon, “Tectonic Setting of the World’s Giant Oil and Gas Fields,” in Giant Oil and Gas Fields of the Decade, 1990–1999, ed. Michel T. Halbouty (Tulsa, OK: American Association of Petroleum Geologists, 2014).
4.Department of Economic Affairs, Population Division, World Population Prospects: Key Findings and Advance Tables, 2015 Revision (New York: United Nations, 2015), https://esa.un.org/unpd/wpp/Publications/Files/Key_Findings_WPP_2015.pdf.
5.International Air Transport Association, 2012 Annual Review, June 2012.
6.Lynn Margulis, “Gaia Is a Tough Bitch,” in The Third Culture: Beyond the Scientific Revolution, ed. John Brockman (New York: Simon and Schuster, 1995).
7.Kim Stanley Robinson, Aurora (New York: Orbit, 2015).
8.University of Zurich, “Great Oxidation Event: More Oxygen through Multicellularity,” ScienceDaily, January 17, 2013, www.sciencedaily.com/releases/2013/01/130117084856.htm.
9.European Space Agency, “Greenhouse Effect, Clouds and Winds,” Venus Express, http://www.esa.int/Our_Activities/Space_Science/Venus_Express/Greenhouse_effect_clouds_and_winds.
10.V.-P. Kostama, M. A. Kreslavsky, and J. W. Head, “Recent High-Latitude Icy Mantle in the Northern Plains of Mars: Characteristics and Ages of Emplacement,” Geophysical Research Letters 33, no. 11 (2006), doi: 10.1029/2006GL025946, and NASA Jet Propulsion Laboratory, “Mars Ice Deposit Holds as Much Water as Lake Superior,” news release, November 22, 2016, https://www.jpl.nasa.gov/news/news.php?release=2016-299.
11.Joe Mason and Michael Buckley, “Cassini Finds Hydrocarbon Rains May Fill Titan Lakes,” Cassini Imaging Central Laboratory for Operations, January 29, 2009, http://ciclops.org/view.php?id=5471&js=1. The liquids on Titan include components of gasoline.
12.Colin N. Waters et al. “The Anthropocene Is Functionally and Stratigraphically Distinct from the Holocene,” Science 351, no. 6269 (January 8, 2016), http://science.sciencemag.org/content/351/6269/aad2622.
13.Dale Jamieson, Reason in a Dark Time (New York: Oxford University Press, 2014).
14.NASA Exoplanet Science Institute, “Exoplanet and Candidate Statistics,” NASA Exoplanet Archive, https://exoplanetarchive.ipac.caltech.edu/docs/counts_detail.html.
CHAPTER 1: THE ALIEN EQUATION
1.C. P. Snow, The Physicists (Boston: Little Brown, 1981).
2.Alan Lightman, A Sense of the Mysterious: Science and the Human Spirit (New York: Vintage, 2006).
3.Eric M. Jones, Where Is Everybody?: An Account of Fermi’s Question (Los Alamos, NM: Los Alamos National Laboratory, 1985), https://www.osti.gov/accomplishments/documents/fullText/ACC0055.pdf.
4.Jones, Where Is Everybody?: 3.
5.Enrico Fermi, “My Observations During the Explosion at Trinity on July 16, 1945,” Fermat’s Library, http://www.atomicarchive.com/Docs/Trinity/Fermi.shtml.
6.As astronomer Jason Wright puts it, “Astronomers stare at the sky professionally with some of the most sensitive equipment in the world. If UFOs were common, we would see them all the time. It strains credulity that armies of amateurs with cameras regularly see UFOs when the professionals with giant telescopes do not.” Jason Wright, “Astronomers and UFOs,” AstroWright, December 1, 2013, https://sites.psu.edu/astrowright/2013/12/01/astronomers-and-ufos/.
7.Michael Hart, “An Explanation for the Absence of Extraterrestrials on Earth,” Quarterly Journal of the Royal Astronomical Society 16 (June 1975): 128. Also see Robert H. Gray, “The Fermi Paradox Is Neither Fermi’s Nor a Paradox,” Astrobiology 15, no. 3 (March 2015): 195–99.
8.Glen David Brin, “The ‘Great Silence’: The Controversy Concerning Extraterrestrial Intelligent Life,” Quarterly Journal of the Royal Astronomical Society 24, no. 3 (1983): 283–309, and James Annis, “An Astrophysical Explanation for the ‘Great Silence,’ ” Journal of the British Interplanetary Society 52 (1999): 19–22.
9.Robin Hansen, The Great Filter—Are We Almost Past It?, September 15, 1998, http://mason.gmu.edu/~rhanson/greatfilter.html.
10.Heike Langenberg, “Slow Gulf Stream During Ice Ages?,” Nature News, December 9, 1999, http://www.nature.com/news/1999/991209/full/news991209-10.html.
11.This could happen in many ways, but the easiest to imagine is a significant population reduction—a “die-off”—that keeps the population’s capacities below the level for a technological/industrial re-emergence. Note that dramatic climate change could result in a species that once had a technological civilization living for hundreds of thousands of years on a world where large-scale agriculture has become impossible. It is very difficult to predict what the evolutionary/sociological outcome of this scenario would be.
12.Matthew F. Dowd, “Fraction of Stars with Planetary Systems, fp, pre-1961,” in The Drake Equation, ed. Douglas A. Vakoch and Matthew F. Dowd (New York: Cambridge University Press, 2015), 56.
13.Steven J. Dick, Plurality of Worlds: The Extraterrestrial Life Debate from Democritus to Kant (Cambridge: Cambridge University Press, 1984), 6.
14.Dick, Plurality of Worlds, 26–27.
15.Dick, Plurality of Worlds, 62.
16.There remains some dispute over what exactly Bruno was convicted for in the heresy charge. Evidence points to more arcane issues of doctrine, rather than astronomy. His views on Copernicanism and other worlds, however, contributed to his career of conflict with the Church. Dorothea Singer, Giordano Bruno: His Life and Thought (1950; repr., New York: Greenwood Press, 1968).
17.Bernard de Fontenelle, Conversations on the Plurality of Worlds (1686; repr., London: J. Cundee, 1803), 112.
18.Dowd, “Fraction of Stars,” 67, and Steven J. Dick, Life on Other Worlds: The 20th-Century Extraterrestrial Life Debate (Cambridge: Cambridge University Press, 1998).
19.Douglas A. Vakoch, ed., Astrobiology, History, and Society: Life Beyond Earth and the Impact of Discovery (Berlin: Springer, 2013), 108.
20.Percival Lowell, “Observations at the Lowell Observatory,” Nature 76 (1907): 446.
21.William Whewell, Of the Plurality of Worlds (1853; repr., Chicago: University of Chicago Press, 2001), 207.
22.Whewell, Plurality of Worlds, 204–5.
23.Alfred Russel Wallace, Man’s Place in the Universe: A Study of the Results of Scientific Research in Relation to the Unity or Plurality of Worlds (London: Chapman and Hall, 1904).
24.Dowd, “Fraction of Stars,” 67.
25.Florence Raulin Cerceau, “Number of Planets with an Environment Suitable for Life, ne, Pre-1961,” in The Drake Equation, eds. Douglas A. Vakoch and Matthew F. Dowd (New York: Cambridge University Press, 2015), 98.
26.Natural Resources Defense Council, “Global Nuclear Stockpiles, 1945–2006,” Bulletin of the Atomic Scientists 62, no. 4 (July/August 2006): 64–66, http://media.hoover.org/sites/default/files/documents/GlobalNuclearStockpiles.pdf.
27.Stephanie Pappas, “Hydrogen Bomb vs. Atomic Bomb: What’s the Difference?,” Live Science, January 6, 2016, https://www.livescience.com/53280-hydrogen-bomb-vs-atomic-bomb.html.
28.Don P. Mitchell, “The R-7 Missile,” http://mentallandscape.com/S_R7.htm.
29.Steve Garber, “Sputnik and the Dawn of the Space Age,” National Aeronautics and Space Administration, last modified October 10, 2007, https://history.nasa.gov/sputnik/.
30.Frank Drake and Dava Sobel, Is Anyone Out There? (New York: Delacorte Press, 1992), 5.
31.Drake and Sobel, Is Anyone Out There?, 27.
32.Drake and Sobel, Is Anyone Out There?, 8–12.
33.Frank Drake, “A Reminiscence of Project Ozma,” Cosmic Search 1, no. 1 (1979): 10.
34.F. Ghigo, “The Tatel Telescope,” National Radio Astronomy Observatory, http://www.gb.nrao.edu/fgdocs/tatel/tatel.html.
35.Drake, “Reminiscence.”
36.John R. Percy, “The Nearest Stars: A Guided Tour,” Astronomical Society of the Pacific, 1986, https://astrosociety.org/edu/publications/tnl/05/stars2.html.
37.Drake, “Reminiscence.”
38.“Early SETI: Project Ozma, Arecibo Message,” SETI Institute, http://www.seti.org/seti-institute/project/details/early-seti-project-ozma-arecibo-message.
39.Drake, “Reminiscence.”
40.“Early SETI: Project Ozma.”
41.Giuseppe Cocconi and Philip Morrison, “Searching for Interstellar Communications,” Nature 184, no. 4690 (September 19, 1959): 844–46.
42.Drake and Sobel, Is Anyone Out There?, 32.
43.Drake and Sobel, Is Anyone Out There?, 45–64.
44.Drake and Sobel, Is Anyone Out There?, 47.
45.Drake and Sobel, Is Anyone Out There?, 54.
46.Drake and Sobel, Is Anyone Out There?, 49.
47.Drake and Sobel, Is Anyone Out There?, 51.
48.Maggie Masetti, “How Many Stars in the Milky Way?,” Blueshift, July 22, 2015, https://asd.gsfc.nasa.gov/blueshift/index.php/2015/07/22/how-many-stars-in-the-milky-way/.
49.Fred Hoyle, The Black Cloud (London: Heinemann, 1957).
50.Drake chose to focus just on our home galaxy, the Milky Way, because the distances to other galaxies are so large. Any source-emitted electromagnetic radiation becomes more difficult to detect the farther away it is.
51.Su-Shu Huang, “The Problem of Life in the Universe and the Mode of Star Formation,” Publications of the Astronomical Society of the Pacific 71, no. 422 (October 1959): 421–24.
52.Stanley L. Miller, “A Production of Amino Acids under Possible Primitive Earth Conditions,” Science 117, no. 3046 (May 15, 1953): 528–29.
53.Drake and Sobel, Is Anyone Out There?, 61.
54.Of course, one can also ask whether a civilization that was far more advanced than ours would still use radio at all. But like the previous issue of life requiring planets, one has to begin somewhere, and its better to underestimate the likelihood of each term than go overboard.
55.Drake and Sobel, Is Anyone Out There?, 62.
56.Drake and Sobel, Is Anyone Out There?, 52.
57.Drake and Sobel, Is Anyone Out There?, 62.
58.Drake and Sobel, Is Anyone Out There?, 64.
59.Jamieson, Reason, 20.
60.“The Television Infrared Observation Satellite Program (TIROS),” NASA Science, May 22, 2016, https://science.nasa.gov/missions/tiros/.
CHAPTER 2: WHAT THE ROBOT AMBASSADORS SAY
1.Franklin O’Donnell, “The Venus Mission: How Mariner 2 Led the World to the Planets,” Jet Propulsion Laboratory website, https://www.jpl.nasa.gov/mariner2/.
2.David R. Williams, “Chronology of Lunar and Planetary Exploration,” Goddard Space Flight Center, last modified August 8, 2017, https://nssdc.gsfc.nasa.gov/planetary/chronology.html.
3.David R. Williams, “Venus Fact Sheet,” Goddard Space Flight Center, last modified December 23, 2016, https://nssdc.gsfc.nasa.gov/planetary/factsheet/venusfact.html.
4.O’Donnell, “The Venus Mission.”
5.Larry Klaes, “Remembering the Early Robotic Explorers,” Centauri Dreams: Imagining and Planning Interstellar Exploration, August 29, 2012, https://www.centauri-dreams.org/?p=24285.
6.O’Donnell, “The Venus Mission.”
7.O’Donnell, “The Venus Mission.”
8.Williams, “Venus Fact Sheet.”
9.William Sheehan and John Edward Westfall, The Transits of Venus (Amherst, NY: Prometheus Books, 2004), 213.
10.Sheehan and Westfall, Transits, 213.
11.Mikhail Ya. Marov, “Mikhail Lomonosov and the Discovery of the Atmosphere of Venus During the 1761 Transit,” in Transits of Venus: New Views of the Solar System and Galaxy, Proceedings of the 196th Colloquium of the International Astronomical Union, ed. D.W. Kurtz (Cambridge: Cambridge University Press, 2004).
12.F. W. Taylor and D. M. Hunten, “Venus: Atmosphere,” in Encyclopedia of the Solar System, 3rd ed., eds. Tilman Spohn, Doris Breuer, and Torrence V. Johnson (Amsterdam: Elsevier, 2014).
13.C. H. Mayer, T. P. McCullough, and R. M. Sloanaker, “Observations of Venus at 3.15 cm Wave Length,” Astrophysical Journal 127, no. 1 (January 1958): 1–10.
14.Paolo Ulivi with David M. Harland, Robotic Exploration of the Solar System: Part 1, The Golden Age, 1957–1982 (Berlin: Springer, 2007), xxxi.
15.Ulivi and Harland, Robotic Exploration, xxxii.
16.“Planetary Temperatures,” Australian Space Academy, http://www.spaceacademy.net.au/library/notes/plantemp.htm.
17.Keay Davidson, Carl Sagan: A Life (New York: Wiley, 1999), 39–56.
18.Ray Spangenburg and Kit Moser, Carl Sagan: A Biography (Westport, CT: Greenwood, 2004), 11–29.
19.Kenneth R. Lang, “Global Warming: Heating by the Greenhouse Effect,” NASA’s Cosmos, 2010, http://ase.tufts.edu/cosmos/view_chapter.asp?id=21&page=1.
20.Tim Sharp, “What Is the Temperature on Earth?,” Space.com, September 28, 2012, https://www.space.com/17816-earth-temperature.html.
21.F. W. Taylor, Planetary Atmospheres (Oxford: Oxford University Press, 2010), 12.
22.Svante Arrhenius, “On the Influence of Carbonic Acid in the Air upon the Temperature of the Ground,” Philosophical Magazine and Journal of Science 41, no. 251 (April 1896): 237–76.
23.Spencer Weart, “The Carbon Dioxide Greenhouse Effect,” The Discovery of Global Warming, January 2017, https://history.aip.org/climate/co2.htm.
24.Spangenburg and Moser, Carl Sagan, 36–38.
25.Davidson, Carl Sagan.
26.O’Donnell, “The Venus Mission.”
27.Tony Reichhardt, “The First Planetary Explorers,” Air and Space Magazine, December 14, 2012, http://www.airspacemag.com/daily-planet/the-first-planetary-explorers-162133105/.
28.O’Donnell, “The Venus Mission.”
29.Asif A. Siddiqi, Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958–2000 (Washington, DC: National Aeronautics and Space Administration, 2002).
30.Taylor, Planetary Atmospheres, 113–15.
31.Taylor, Planetary Atmospheres, 114–24.
32.The cold trap works by keeping water in the lower part of the atmosphere. As water vapor rises, it eventually cools and condenses, falling back to Earth. This process intensifies at the tropopause (fifteen kilometers above sea level), where air temperatures drop far below freezing. Thus, all remaining water in the atmosphere is frozen out. Michael Denton, “The Cold Trap: How It Works,” Evolution News and Science Today, May 10, 2014, https://evolutionnews.org/2014/05/the_cold_trap_h/.
33.Davidson, Carl Sagan.
34.Spangenburg and Moser, Carl Sagan, 34–65.
35.“Mars Exploration Rovers: Step-by-Step Guide to Entry, Descent, and Landing,” Jet Propulsion Laboratory, https://mars.nasa.gov/mer/mission/tl_entry1.html.
36.Steven W. Squyres, Roving Mars: Spirit, Opportunity, and the Exploration of the Red Planet (New York: Hyperion, 2005), 292–93.
37.Ulivi and Harland, Robotic Exploration, xxxiii–xxxiv.
38.Vakoch, Astrobiology, History, and Society, 108.
39.William Sheehan, The Planet Mars: A History of Observation and Discovery (Tucson, AZ: University of Arizona Press, 1996).
40.Sheehan, Planet Mars.
41.Rod Pyle, “Alone in the Darkness: Mariner 4 to Mars, 50 Years Later,” California Institute of Technology, July 14, 2015, https://www.caltech.edu/news/alone-darkness-mariner-4-mars-50-years-later-47324.
42.“The Dead Planet,” New York Times, July 30, 1965.
43.Ulivi and Harland, Robotic Exploration, 108–12.
44.Ulivi and Harland, Robotic Exploration, 114–16.
45.Elizabeth Howell, “Mariner 9: First Spacecraft to Orbit Mars,” Space.com, November 12, 2012, https://www.space.com/18439-mariner-9.html.
46.“Welcome to the Planets,” Jet Propulsion Laboratory, https://pds.jpl.nasa.gov/planets/choices/mars1.htm.
47.Davidson, Carl Sagan, 279–80.
48.David R. Williams, “Viking Mission to Mars,” Goddard Space Flight Center, last modified September 5, 2017, https://nssdc.gsfc.nasa.gov/planetary/viking.html, and “A Chronology of Mars Exploration,” National Aeronautics and Space Administration, last modified April 16, 2015, https://history.nasa.gov/printFriendly/marschro.htm.
49.“Overview: The Mars Exploration Program,” National Aeronautics and Space Administration, https://mars.nasa.gov/programmissions/overview/.
50.Robert Haberle, interview with the author, March 20, 2017.
51.“The History of Mars General Circulation Model,” Mars Climate Modeling Center, https://spacescience.arc.nasa.gov/mars-climate-modeling-group/history.html.
52.Haberle, interview.
53.Williams, “Viking Mission to Mars.”
54.Williams, “Viking Mission to Mars.”
55.Derek Hayes, Historical Atlas of the Pacific Northwest (Vancouver, BC: Douglas and McIntyre, 2001).
56.Anders Persson, “Hadley’s Principle: Part 1—A Brainchild with Many Fathers,” Weather 63, no. 11 (November 2008): 335–38.
57.David R. Williams, “Mars Fact Sheet,” Goddard Space Flight Center, last modified December 23, 2016, https://nssdc.gsfc.nasa.gov/planetary/factsheet/marsfact.html.
58.Haberle, interview.
59.Rob Gutro, “Polar Vortex Enters Northern U.S.,” Goddard Space Flight Center, 2014, https://www.nasa.gov/content/goddard/polar-vortex-enters-northern-us/#.WcAeq62UUo-.
60.Laura Dattaro, “Check the Weather on Mars, Where NASA’s MAVEN Is Headed,” Weather Channel, November 19, 2013, https://weather.com/science/news/check-weather-mars-where-nasas-maven-headed-20131119.
61.Andrew P. Ingersoll, Planetary Climates (Princeton, NJ: Princeton University Press, 2013), 96–106.
62.National Aeronautics and Space Administration, “Minerals in Mars ‘Berries’ Adds to Water Story,” news release, March 18, 2004, https://mars.nasa.gov/mer/newsroom/pressreleases/20040318a.html.
63.National Aeronautics and Space Administration, “NASA Rover Finds Old Streambed on Martian Surface,” news release, September 27, 2012, https://www.nasa.gov/mission_pages/msl/news/msl20120927.html.
64.Michael H. Carr and James W. Head III, “Geologic History of Mars,” Earth and Planetary Science Letters 294, nos. 3–4 (June 1, 2010): 185–203.
65.Paul L. Montgomery, “Throngs Fill Manhattan to Protest Nuclear Weapons,” New York Times, June 13, 1982.
66.Robert S. Norris and Hans M. Kristensen, “Global Nuclear Weapons Inventories, 1945–2010,” Bulletin of the Atomic Scientists 66, no. 4 (July/August 2010): 77–83.
67.R. P. Turco et al., “Nuclear Winter: Global Consequences of Multiple Nuclear Explosions,” Science 222, no. 4630 (December 23, 1983): 1283–92.
68.Jill Lepore, “The Atomic Origins of Climate Science,” The New Yorker, January 30, 2017, http://www.newyorker.com/magazine/2017/01/30/the-atomic-origins-of-climate-science.
69.Jacob Darwin Hamblin, “Badash, A Nuclear Winter’s Tale,” Metascience 21, no. 3 (November 2012): 727–31.
CHAPTER 3: THE MASKS OF EARTH
1.“Earth’s Early Atmosphere,” Astrobiology Magazine, December 2, 2011, http://www.astrobio.net/geology/earths-early-atmosphere/.
2.John Reed, “Inside the Army’s Secret Cold War Ice Base,” Defense Tech, April 6, 2012, https://www.defensetech.org/2012/04/06/inside-the-armys-secret-cold-war-ice-base/, and Malcolm Mellor, Oversnow Transport (Hanover, NH: U.S. Army Cold Regions Research and Engineering Laboratory, 1963), http://www.dtic.mil/dtic/tr/fulltext/u2/404778.pdf.
3.“Trail Blazed by Renowned Explorer Leads Danish, U.S. Scouts to Arctic Adventure,” Army Research and Development, December 1960, 14.
4.“The Ice Sheet,” Visit Greenland, http://www.greenland.com/en/about-greenland/nature-climate/the-ice-cap/.
5.Frank J. Leskovitz, “Camp Century, Greenland: Science Leads the Way,” http://gombessa.tripod.com/scienceleadstheway/id9.html.
6.Leskovitz, “Camp Century.”
7.Leskovitz, “Camp Century.”
8.Leon E. McKinney, “Camp Century Greenland,” West-Point.org, http://www.west-point.org/class/usma1955/D/Hist/Century.htm.
9.Gordon de Q. Robin, “Profile Data, Greenland Region,” in The Climate Record in Polar Ice Caps, ed. Gordon de Q. Robin (1983; repr., Cambridge: Cambridge University Press, 2010), 100–101.
10.Joseph Gale, Astrobiology of Earth: The Emergence, Evolution, and Future of Life on a Planet in Turmoil (Oxford: Oxford University Press, 2009), 125–26.
11.John S. Schlee, “Our Changing Continent,” United States Geological Survey, last modified February 15, 2000, https://pubs.usgs.gov/gip/continents/.
12.Gale, Astrobiology of Earth, 125.
13.Willi Dansgaard, Frozen Annals: Greenland Ice Cap Research (Copenhagen: Niels Bohr Institute, 2005), 55–56.
14.Dansgaard, Frozen Annals, 58.
15.W. Dansgaard et al., “One Thousand Centuries of Climate Record from Camp Century on the Greenland Ice Sheet,” Science 166, no. 3903 (October 17, 1969): 377–80. See also “The Younger Dryas,” NOAA National Centers for Environmental Information, https://www.ncdc.noaa.gov/abrupt-climate-change/The%20Younger%20Dryas.
16.Manned Spacecraft Center, “Apollo 8 Onboard Voice Transcription, As Recorded on the Spacecraft Onboard Recorder (Data Storage Equipment),” January 1969, 113–14, https://www.jsc.nasa.gov/history/mission_trans/AS08_CM.PDF.
17.Earthrise, Time, http://100photos.time.com/photos/nasa-earthrise-apollo-8.
18.K. M. Cohen, S. Finney, and P. L. Gibbard, “International Chronostratigraphic Chart,” International Commission on Stratigraphy, January 2013, http://www.stratigraphy.org/icschart/chronostratchart2013-01.pdf.
19.Ann Zabludoff, “Lecture 13: The Nebular Theory of the Origin of the Solar System,” University of Arizona Department of Astronomy and Steward Observatory, http://atropos.as.arizona.edu/aiz/teaching/nats102/mario/solar_system.html.
20.C. Goldblatt et al., “The Eons of Chaos and Hades,” Solid Earth Discussions 1, no. 1 (2010), 1–3.
21.Goldblatt et al., “Chaos and Hades.”
22.Thomas Holtz, “GEOL 102 Historical Geology: The Archean Eon,” University of Maryland Department of Geology, last modified January 18, 2017, https://www.geol.umd.edu/~tholtz/G102/lectures/102archean.html.
23.Stanly M. Awramik and Kenneth J. McNamara, “The Evolution and Diversification of Life,” in Planets and Life: The Emerging Science of Astrobiology, eds. Woodruff R. Sullivan III and John A Baross (Cambridge University Press, 2007), 313–16.
24.Awramik and McNamara, “Evolution and Diversification” 313–18.
25.Z. X. Li et al., “Assembly, Configuration, and Break-up History of Rodinia: A Synthesis,” Precambrian Research, 160 (2008): 179–210.
26.David Catling and James F. Kasting, “Planetary Atmospheres and Life,” in Planets and Life: The Emerging Science of Astrobiology, eds. Woodruff R. Sullivan III and John A Baross (Cambridge University Press, 2007), 99.
27.Awramik and McNamara, “Evolution and Diversification,” 321.
28.Donald E. Canfield, Oxygen: A Four Billion Year History (Princeton, NJ: Princeton University Press, 2014), 145–46.
29.“PETM: Global Warming, Natural,” Weather Underground, https://www.wunderground.com/climate/PETM.asp?MR=1.
30.Canfield, Oxygen, 13.
31.Canfield, Oxygen, 14.
32.“Opening a Tectonic Zipper,” Seismo Blog (UC Berkeley Seismology Lab), April 5, 2010, http://seismo.berkeley.edu/blog/2010/04/05/opening-a-tectonic-zipper.html.
33.Canfield, Oxygen, 14.
34.Canfield, Oxygen, 14.
35.Canfield, Oxygen, 41.
36.Canfield, Oxygen, 41.
37.Gale, Astrobiology of Earth, 110–11.
38.Canfield, Oxygen, 41–42.
39.David C. Catling, Astrobiology: A Very Short Introduction (Oxford: Oxford University Press, 2013), 50–55.
40.Catling, Astrobiology, 52.
41.Alexej M. Ghilarov, “Vernadsky’s Biosphere Concept: An Historical Perspective,” Quarterly Review of Biology 70, no. 2 (June 1995): 193–203.
42.Irina Trubetskova, “Vladimir Ivanovich Vernadsky and His Revolutionary Theory of the Biosphere and the Noosphere,” University of New Hampshire, http://www-ssg.sr.unh.edu/preceptorial/Summaries_2004/Vernadsky_Pap_ITru.html.
43.Ghilarov, “Vernadsky’s Biosphere Concept.”
44.Vladimir Vernadsky, The Biosphere, trans. David B. Langmuir (New York: Copernicus, 1998), 44, 56.
45.Ghilarov, “Vernadsky’s Biosphere Concept.”
46.James Lovelock, Homage to Gaia: The Life of an Independent Scientist (New York: Oxford University Press, 2000).
47.Lovelock, Homage to Gaia, 242.
48.Lovelock, Homage to Gaia, 243.
49.Lovelock, Homage to Gaia, 243.
50.Lovelock, Homage to Gaia, 243–44.
51.Lovelock, Homage to Gaia, 253.
52.Lovelock, Homage to Gaia, 255.
53.Joel Bartholomew Hagen, Douglas Allchin, and Fred Singer, Doing Biology (New York: HarperCollins, 1996).
54.Lovelock, Homage to Gaia, 256–57.
55.Michael Ruse, “Earth’s Holy Fool?,” Aeon, https://aeon.co/essays/gaia-why-some-scientists-think-it-s-a-nonsensical-fantasy.
56.John Postgate, “Gaia Gets Too Big for Her Boots,” New Scientist, April 7, 1988.
57.Ruse, “Earth’s Holy Fool?”
58.Lovelock, Homage to Gaia, 265.
59.Ruse, “Earth’s Holy Fool?”
CHAPTER 4: WORLDS BEYOND MEASURE
1.This section on Thomas See is based on information found in Thomas J. Sherrill, “A Career of Controversy: The Anomaly of T.J.J. See,” Journal for the History of Astronomy 30, no. 1 (February 1999): 25–50, and William Sheehan, “The Tragic Case of T.J.J. See,” Mercury 31, no. 6 (November 2002): 34.
2.Personal correspondence.
3.Amy Veltman, “Dr. Jill Tarter: Looking to Make ‘Contact,’ ” Space.com, November 12, 1999, https://web.archive.org/web/20081005020231/http://www.space.com/peopleinterviews/tarter_profile_991112.html.
4.“Jill Tarter,” SETI Institute, https://www.seti.org/users/jill-tarter.
5.Jill Tarter, interview with the author.
6.John Billingham, “SETI: The NASA Years,” in Searching for Extraterrestrial Intelligence: SETI Past, Present, and Future, ed. H. Paul Shuch (Berlin: Springer, 2011), 70.
7.Jesse L. Greenstein and David C. Black, “Detection of Other Planetary Systems,” in The Search for Extraterrestrial Intelligence: SETI, eds. Philip Morrison, John Billingham, and John Wolfe (Washington, DC: NASA Scientific and Technical Information Office, 1977).
8.Greenstein and Black, “Detection.”
9.Tarter, interview.
10.David C. Black and William E. Brunk, eds., An Assessment of Ground-Based Techniques for Detecting Other Planetary Systems, Volume 1: An Overview (Moffett Field, CA: National Aeronautics and Space Administration, 1979), 18.
11.Michael D. Lemonick, Mirror Earth: The Search for Our Planet’s Twin (New York: Walker, 2012), 55.
12.Lemonick, Mirror Earth.
13.Lemonick, Mirror Earth, 52–53.
14.Lemonick, Mirror Earth, 58.
15.Andrew Lawler, “Bill Borucki’s Planet Search,” Air and Space, May 2003, http://www.airspacemag.com/space/bill-boruckis-planet-search-4545405/?no-ist.
16.Lawler, “Borucki’s Planet Search.”
17.Lawler, “Borucki’s Planet Search.”
18.William J. Borucki et al., “Kepler Planet-Detection Mission: Introduction and First Results,” Science 327, no. 5968 (February 19, 2010): 977–80.
19.“Liftoff of Kepler: On a Search for Exoplanets in Some Way Like Our Own,” National Aeronautics and Space Administration, March 6, 2009, https://www.nasa.gov/multimedia/imagegallery/image_feature_2123.html.
20.Natalie Batalha, interview with the author.
21.Michele Johnson, “NASA’s Kepler Mission Announces a Planet Bonanza, 715 New Worlds,” National Aeronautics and Space Administration, February 26, 2014, https://www.nasa.gov/ames/kepler/nasas-kepler-mission-announces-a-planet-bonanza.
22.“Exoplanet Anniversary: From Zero to Thousands in 20 Years,” Jet Propulsion Laboratory, October 6, 2015, https://www.jpl.nasa.gov/news/news.php?feature=4733.
23.Batalha, interview.
24.“Star: KOI-961—3 PLANETS,” Extrasolar Planets Encyclopaedia, http://exoplanet.eu/catalog/?f=‘KOI-961’+in+name.
25.Lee Billings, “Newfound Super-Earth Boosts Search for Alien Life,” Scientific American, April 19, 2017, https://www.scientificamerican.com/article/newfound-super-earth-boosts-search-for-alien-life/.
26.Shannon Hall, “This Super-Saturn Alien Planet Might Be the New ‘Lord of the Rings,’ ” Space.com, February 3, 2015, https://www.space.com/28435-super-saturn-alien-planet-rings.html.
27.Andrew Fazekas, “Diamond Planet Found—Part of ‘Whole New Class’?,” National Geographic, October 13, 2012, http://news.nationalgeographic.com/news/2012/10/121011-diamond-planet-space-solar-system-astronomy-science/.
28.“Hubble Finds a Star Eating a Planet,” Hubble Space Telescope, May 20, 2010, https://www.nasa.gov/mission_pages/hubble/science/planet-eater.html.
29.Amelie Saintonge, “How Many Stars Are Born and Die Each Day?,” Ask An Astronomer, last modified June 27, 2015, http://curious.astro.cornell.edu/about-us/83-the-universe/stars-and-star-clusters/star-formation-and-molecular-clouds/400-how-many-stars-are-born-and-die-each-day-beginner.
30.Mike Wall, “Nearly Every Star Hosts at Least One Alien Planet,” Space.com, March 4, 2014, https://www.space.com/24894-exoplanets-habitable-zone-red-dwarfs.html.
31.Robert Sanders, “Astronomers Answer Key Question: How Common Are Habitable Planets?” University of California, Berkeley, November 4, 2013, http://news.berkeley.edu/2013/11/04/astronomers-answer-key-question-how-common-are-habitable-planets/.
32.In our paper, we set the pessimism line between 10–24 and 10–22 for technical reasons. Throughout the book, we will use the more conservative value of 10–22. .
33.Ross Andersen, “Fancy Math Can’t Make Aliens Real,” Atlantic, June 17, 2016, https://www.theatlantic.com/science/archive/2016/06/fancy-math-cant-make-aliens-real/487589/, and Ethan Siegel, “Humanity May Be Alone in the Universe,” Forbes, June 21, 2016, https://www.forbes.com/sites/startswithabang/2016/06/21/humanity-may-be-alone-in-the-universe/.
34.Adam Frank, “Yes, There Have Been Aliens,” New York Times, June 10, 2016, https://www.nytimes.com/2016/06/12/opinion/sunday/yes-there-have-been-aliens.html.
35.Ernst Mayr, “Can SETI Succeed? Not Likely,” The Planetary Society, http://daisy.astro.umass.edu/~mhanner/Lecture_Notes/Sagan-Mayr.pdf.
36.Brandon Carter, “The Anthropic Principle and its Implications for Biological Evolution,” Philosophical Transactions of the Royal Society A 310, no. 1512 (December 1983): 347–63.
37.It’s worth noting that authors like astrophysicist Mario Livio have presented arguments that undermine the basis for Carter’s work. Mario Livio, “How Rare Are Extraterrestrial Civilizations, and When Did They Emerge?” The Astrophysical Journal 511, no. 1 (1999): 429–31.
38.Hubert P. Yockey, “A Calculation of the Probability of Spontaneous Biogenesis by Information Theory,” Journal of Theoretical Biology 67, no. 3 (August 7, 1977): 377–98.
39.Wentao Ma et al., “The Emergence of Ribozymes Synthesizing Membrane Components in RNA-Based Protocells,” Biosystems 99, no. 3 (March 2010): 201–9.
CHAPTER 5: THE FINAL FACTOR
1.William Bains. “Many Chemistries Could Be Used to Build Living Systems,” Astrobiology 4, no. 2 (June 2004): 137–67.
2.J. R. Haas, “The Potential Feasibility of Chlorinic Photosynthesis on Exoplanets,” Astrobiology 10, no. 9 (November 2010): 953–63.
3.J. Dulcic, A. Soldo, and I. Jardas, “Adriatic Fish Biodiversity and Review of Bibliography Related to Croatian Small-Scale Coastal Fisheries,” http://www.faoadriamed.org/pdf/publications/td15/wp_dulcica.pdf.
4.Sharon Kingsland, Modeling Nature: Episodes in the History of Population Ecology (Chicago: University of Chicago Press, 1985), 106.
5.Philip J. Davis, “Carissimo Papà: A Great Fish Story,” SIAM News 38, no. 8 (October 2005).
6.Kingsland, Modeling Nature, 4.
7.Mark Kot, Elements of Mathematical Ecology (Cambridge: Cambridge University Press, 2001), 11.
8.Kingsland, Modeling Nature, 109.
9.Kingsland, Modeling Nature, 106–15.
10.Kingsland, Modeling Nature, 1.
11.Rafael Reuveny, “Taking Stock of Malthus: Modeling the Collapse of Historical Civilizations,” Annual Review of Resource Economics 4 (2012): 303–29.
12.Reuveny, “Taking Stock of Malthus,” 303.
13.Erich von Däniken, Chariots of the Gods? (1968; New York: Putnam, 1970).
14.Jared Diamond, Collapse: How Societies Choose to Fail or Succeed (New York: Viking, 2005).
15.James A. Brander and M. Scott Taylor, “The Simple Economics of Easter Island: A Ricardo-Malthus Model of Renewable Resource Use,” American Economic Review 88, no. 1 (March 1998): 119–38.
16.Bill Basener and David S. Ross, “Booming and Crashing Populations and Easter Island,” SIAM Journal on Applied Mathematics 65, no. 2 (2004): 684–701.
17.Adam Frank and Woodruff Sullivan, “Sustainability and the astrobiological perspective,” Anthropocene 5 (March 2014): 32.
18.Adam Frank, “Could You Power Your Home With A Bike?,” NPR, December 8, 2016, http://www.npr.org/sections/13.7/2016/12/08/504790589/could-you-power-your-home-with-a-bike.
19.Rudy M. Baum Sr., “Future Calculations: The First Climate Change Believer,” Distillations, Summer 2016, https://www.chemheritage.org/distillations/magazine/future-calculations.
20.L. Miller, F. Gans, and A. Kleidon, “Estimating Maximum Global Land Surface Wind Power Extractability and Associate Climatic Consequences,” Earth System Dynamics 2 (2011): 112.
21.It’s worth mentioning that it is possible that the distribution of exo-civilizations might be more complicated than providing a well-defined average. There might, for example, be two peaks in the lifetimes of a large sample of exo-civilizations (one short and long). This kind of result would be interesting in its own right.
CHAPTER 6: THE AWAKENED WORLDS
1.Marina Alberti, Cities That Think Like Planets (Seattle: University of Washington Press, 2016).
2.Drake and Sobel, Is Anyone Out There?.
3.Drake and Sobel, Is Anyone Out There?. Also, “First Soviet-American Conference on Communication with Extraterrestrial Intelligence,” Icarus 16, no. 2 (April 1972): 412.
4.Kenneth I. Kellermann, “Nicolay Kardashev,” National Radio Astronomy Observatory, http://rahist.nrao.edu/kardashev_reber-medal.shtml.
5.Nikolai Kardashev, “Transmission of Information by Extraterrestrial Civilizations,” Soviet Astronomy 8, no. 2 (September/October 1964): 217, and Milan M. Cirkovic, “Kardashev’s Classification at 50+: A Fine Vehicle with Room for Improvement,” Serbian Astronomical Journal 191 (2015): 1–15.
6.“Energy of a Nuclear Explosion,” The Physics Factbook, https://hypertextbook.com/facts/2000/MuhammadKaleem.shtml.
7.Freeman J. Dyson, “Search for Artificial Stellar Sources of Infrared Radiation,” Science 131, no. 3414 (June 3, 1960): 1667–68.
8.J. T. Wright et al.,“The Ĝ Infrared Search for Extraterrestrial Civilizations with Large Energy Supplies, II. Framework, Strategy, and First Result,” Astrophysical Journal 792, no. 1 (2014): 27.
9.Cirkovic, “Kardashev’s Classification.”
10.Carl Sagan, Carl Sagan’s Cosmic Connection: An Extraterrestrial Perspective, ed. Jerome Agel (Cambridge: Cambridge University Press, 2000).
11.Michio Kaku, “The Physics of Extraterrestrial Civilizations,” http://mkaku.org/home/articles/the-physics-of-extraterrestrial-civilizations/.
12.Isaac Asimov, Foundation (New York: Gnome Press, 1951).
13.Second Law of Thermodynamics, http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/seclaw.html.
14.Matt Williams, “What is the Weather Like on Mercury?,” Universe Today, July 24, 2017, https://www.universetoday.com/85348/weather-on-mercury/.
15.Volatility is a concept from physics and chemistry and is the tendency of a substance to vaporize. Volatiles in planetary science are substances that will vaporize (or boil) at “normal” temperatures and pressures. Iron, for example, is not considered a volatile, while water, CO2, and methane are volatiles.
16.L. Kaltenegger and D. Sasselov, “Detecting Planetary Geochemical Cycles on Exoplanets: Atmospheric Signatures and the Case of SO2,” Astrophysical Journal 708, no. 2 (2010): 1162–67, and J. F. Kasting and D. E. Canfield, “The Global Oxygen Cycle,” in Fundamentals of Geobiology, eds. A. H. Knoll, D. E. Canfield, and K. O. Konhauser (Hoboken, NJ: Wiley-Blackwell, 2012), 93–104.
17.Adam Frank, Axel Kleidon, and Marina Alberti, “Earth as a Hybrid Planet: The Anthropocene in an Evolutionary Astrobiological Context,” Anthropocene (forthcoming).
18.Donald Canfield, “The Early History of Atmospheric Oxygen,” Annual Review of Earth and Planetary Sciences 33 (2005): 1–36.
19.Eleni Stavrinidou et al., “Electronic Plants,” Science Advances 1, no. 10 (November 2015).
20.David Grinspoon, The Earth in Human Hands (New York: Grand Central Publishing, 2016).
21.Based on Vernadsky’s writings, the Jesuit priest and paleontologist Pierre Teilhard de Chardin worked on his own, decidedly more mystical version of the noosphere. P. Teilhard de Chardin, The Phenomenon of Man, trans. Bernard Wall (New York: Harper, 1959), 238.
22.The “Big History Project” is an attempt to teach history in a way that puts humanity in its place along with the rest of the cosmos. See https://www.bighistoryproject.com/home.