Cambridge University Press 978-1-107-00641-6 - Frontiers of Astrobiology Edited by Chris Impey, Jonathan Lunine and José Funes Index More Information

Cambridge University Press 978-1-107-00641-6 - Frontiers of Astrobiology Edited by Chris Impey, Jonathan Lunine and José Funes Index More information

Index

Page numbers in italics refer to ﬁgures and tables.

Acasta Gneiss, 52 Allen Telescope Array (ATA), anthropomorphism, 266, 291 accretion heating, 205 18, 295–7, 296, 299, 301, antibiotics, in search for acetylene, 189–90 302–3 non-standard life, 39 Achaean era, 188 Alpha Centauri B, 234 anti-greenhouse effect, 188–9 Acidiphilium spp, 160 altimeters, 182, 183, 185 aragonite, 64 Acidithiobacillus ferrooxidans, Altman, S., 62 Archaea (domain), 12, 29, 57, 160 aluminum, 205 94, 122n, 123, 133, 160, Acidobacteria, 160 Amazonian (cold and dry) 162, 164 Acinetobacter, 160 Period, 158, 172 metabolism in, 49, 58–9 Actinobacteria, 160, 164 Earth analogs for, 162–5 Archean Eon, 12, 53, 54–5, 97, adenosine triphosphate (ATP), amino acids, 49 118, 135, 159 49, 50, 136 as biomarker, 25 evolution of habitability in, Aeromonas, 160 in meteorites, 64 115–28 aerosols (tholins), on Titan, synthesis of, 12, 49, 59 fossils from, 102–3, 108 187, 188, 190, 192, ammonia, 120, 125, 192–3, late, 134 194 205, 214, 216–17, 219 Arecibo, Puerto Rico, Africa, 53, 55, 95, 100, 107, ammonia hydrates, 204, 208 observatory at, 294, 299, 119, 119, 126 anaerobic metabolism, 123–5, 303 Akilia island, 92, 95, 108 141 Ariel, 203, 212 albedo, 121n, 242, 270 analysis, in life theory Aristotle, 291 ALFA feed array, 294 formation, 28, 31 Arthrobacter, 164 algae, 122, 165 Andes Mountains, 163, 164 asteroid belt, 90, 205, 213, photosynthetic, 160 animals: 221 ALH84001 (Martian foundation for evolution of, asteroids: meteorite), 7, 17, 35–7, 35 135, 143, 144 icy, 203–9 alkalinity, 8 macroscopic, 143–5 ingredients for habitability Allan Hills Meteorite Antarctica, 162, 173, 179 of, 204–9 (ALH84001), 7, 17, 35–7, extreme environment of, missions to, 203–4 35 32, 48, 161 position and temperature Allen, Paul, 295 Mars meteorite in, 35–7 of, 204

306

© in this web service Cambridge University Press www.cambridge.org Cambridge University Press 978-1-107-00641-6 - Frontiers of Astrobiology Edited by Chris Impey, Jonathan Lunine and José Funes Index More information

Index 307

property table for, 203 prebiotic, 124 biochemistry, unity of, 11 water on, 84, 201–9, 213–16 and redox state, 122–8 bio-cosmological principle, astrobiology: vs. Mars, 168 266 aims of, 9, 18 weakly reduced, 123 biology, advances in, 9 breakthroughs in, 8–9 see also Great Oxydation biomarkers, 17 as discipline, 3 Event biosignature gasses, 239–41 habitability as goal of, 288 atmospheric erosion, 237 biosignatures, 239–42 history of, 6–9 Australia, 55, 92, 95, 100, 115, biosynthesis, 189 and human culture, 18 159 Black Cloud (character), 27–8 and humility, 18–19 cherts in, 98, 105, 106, 125 black shales, biomarkers in, new synthesis in, 5–19 autotrophic metabolic 126–7 and origin of life, 11–13 pathways, 12 Blanc, Michel, 175–97, 202 questions proposed by, 6, 9 autotrophs (self-feeding), 48 “boring billion,” 135, 139 SETI and, 288 Axel Heiberg Island, as Mars bottom-up approach, 11, 12, study week on, 3–4 analog, 161, 162 239 use of term, 6, 9 Azua-Bustos, Armando, brain, 145 astrometry planet search 157–73 Brevibacillus, 164 technique, 235 brown dwarfs, 251 astronomers, astronomy, Bacillus, 164 brucite, 64, 214 historical, 5, 6, 254–5 bacteria: Buick, R., 135 Atacama Desert, as Mars fossil record of, 132 analog, 163–5, 163 in Mars analogs, 162–4 Calamarians (characters), 27–8 atmosphere: metabolism in, 58–9, 60 calcium–aluminum blurring effects of, 254, 271 microaerophilic, 137 inclusions, 205 as dynamic, 168 in Proterozoic oceans, California, University of, at erosion of, 237 138–9, 141 Berkeley: of Europa, 184 Bacteria (domain), 12, 57, Radio Astronomy of exoplanets, 242–4, 122n Laboratory at, 295 266–80 metabolism in, 49 telescope at, 294–5 of Mars, 158, 160–1, 165–73, banded iron formations (BIF), Callisto, 176, 178, 178, 192, 170 55, 56, 121, 135–6 195, 250 spectroscopic analysis of, Barberton Greenstone Belt, 53, Cambrian Period, 116 268 95, 99–100, 101, 104, 105, Campbelltown Rotary of Titan, 185, 186, 187–9, 107, 108, 109 Observatory, 295 192, 194 Baross, John, 5–19 Canada: of transiting super-Earths, Beacon Valley, as Mars analog, glaciation in, 119 243 161, 162, 165 Mars analogs in, 159, 161 atmosphere, Earth, 52, 63, 89, Beagle, HMS, 5, 17 old rocks in, 52, 90, 92 109, 115, 185, 239–40 Benner, Steven, 25–45 canali, 157 effect of early life on, 123–5 Benner laboratory, 43 Canﬁeld, Donald, 136, 138 before GOE, 122–3 Benz, Willy, 73–84 carbohydrates, 25 oxygen stabilization and benzene, 187, 189, 190, 191 carbon: regulations in, 136–8 Berkner, L. V., 7 isotopes, 10, 102–3, 104, postbiotic, 124 bilateralism, 145–6 139

308 Index

carbon (cont.) Cell Theory of Life, 36 Clarke, Arthur C., 18, 292 as life essential, 10, 13, 89, cellular signatures, 10, 100–1 Class III habitats, 176, 176, 100–1, 214, 241 Cellulomonas, 164 180, 196 in microbial metabolism, Cenozoic epoch, 96 Europa as potential, 180–1 54–5, 67, 96–7 Centaurs, 216 Class IV habitats, 176, 176, organic, 121, 139, 142 Central Bureau of 177, 196 in respiration, 121–2 Astronomical Telegrams, clathrate hydrates, 204–5, carbonaceous “snowﬂakes,” 301 212, 214, 219, 221 120 Central Park, 117 clays, as catalysts in origin of carbon dioxide, 13, 244, 271, Ceres, 218, 219, 220–1 life, 13, 64 272, 274 habitability potential for, Cleland, C. E., 10 as carbon source, 12 202, 203, 203, 213, 214, climate: in Earth’s atmosphere, 91, 215, 216 in Archean Eon, 116–22, 120–1, 139–40, 267 Charon, 201, 216, 218–19, 125 in Mars atmosphere, 165, 221–2 of Mars, 169, 172–3 168–71, 172 habitability potential of, in Proterozoic, 139–41 carbon ﬁxation, 54, 67 202, 203, 218, 219–22 Clinton, Bill, 8 Carboniferous Era, 159 chasmolithic organisms, 103 Clostridium, 160 Cassini Composite Infrared chemical signatures, 10 clouds, 242, 274 Spectrometer, 191 chemical systems, as life cnidarians, 145 Cassini–Huygens mission, 8, essential, 27 coal beds, 51 185, 186, 187, 189, 191, chemistry: Coastal Mountain Range, 163, 192, 195–6, 212, 220 origins paradox in, 40–1 164 Cassini Imaging Science pre-biotic, 8, 39–41, 63–5 cobalt, 13 Subsystem (ISS), 187 chemolithotrophs, 96–7, 97, Cocconi, Giuseppe, 287 Cassini Infra–Red 100, 104–5, 109, 161 collisions: Spectrometer, 212 chemoorganotrophs, 97, 100, with Earth, 90 Cassini Ion and Neutral Mass 101, 105, 109 of landmasses, 52 Spectrometer (INMS), 187, cherts, oxygen isotopes in, in planet formation, 74–6, 191, 212, 220 116–17 83 Cassini Radio Science “chicken and egg” problem, Colour Peak, 161 Subsystem, 193 40, 127 comets, 90 Cassini/VIMS instrument, 189, China, 142, 144 in asteroid belt, 213 193 Chlorella, 160 as building blocks for life, Castillo-Rogez, Julie, 201–22 CHNOPS (key elements for 11 catalysis, as life essential, 50 life), 180 commensal observations, catalysts, in metabolism, Christalline Entity (character), 294–5 60–7, 65, 66 27 common ancestry, 31, 32, 39 caves, as Mars analogs, 164–5 chromium, 135 complementarity, 41, 43–4, 42 Cech, T. R., 62 Chroococcidiopsis, 164 conduction, 207–8 cells: Chryse Planitia, 162–3 contamination, interstellar, 7 formation of early, 94, Chyba, C. F., 10, 63 continents, 95 100–1 citric acid cycle (TCA), 59 convection, 207–9, 215 as foundation of life, 36 Clark, R. N., 189 mobile-lid, 212

Index 309

Copernican Principle, De Duve, C., 12 Drake, Frank, 286, 287, 290 Copernican revolution, deep hot biosphere, 38 Drake equation, 287–91 16, 245–6, 289, 301 Deinococcus radiodurans, 99 complications and Copernicus, Nicolaus, 245 deoxyribonucleic acid (DNA), assumptions of, 288–9 Copley, Shelley, 48–67 11, 62, 122 formula for, 287–8 copper, 13 complementarity in, 41, probabilities and corals, 145 43–4 predictions of, 289–91 coronographs, 245, 256, 270 GACTZP, 44–5 drop stones, 117 corotation (zeroth order) in LUCA, 58–9 Drossart, P., 273 resonance, 78–9 as molecular genetic Dunaliella, 160, 165 CoRoT (CNES) missions, 197, system, 26, 27, 29 Dune (Herbert), 172 254, 262 polymerases, 44 dust, as building blocks for CoRoT-7b (planet), 254, 262, and protein production, 40 life, 11 269 sequencing, 30 dust analyzer, 183 Cosmic Vision Plan, 195 stability of, 38 dwarf planets, 213, 216, Coustenis, Athena, 175–97, synthetic, 41, 43–4 218–19, 269 202 Derry, L. A., 142 crater-counting, 183 Desch, S. J., 217, 219 Earth: crater relaxation, 210 deserts: as appropriate setting for cratons, 52 life in, 164, 172 life, 89–110, 216, 232, 291 formation of, 133–4 on Mars, 172 biological “Renaissance” of, Crick, F. H. C., 41, 42, 43 oldest, 163 141–6 crust, Earth’s, 52, 91–2 Desulfosporosinus, 160 climate history of, 116–22 cryogenic biospheres, 289 deuterium, 251 composition of, 73 cryovolcanism, 190–1, 193, diagenesis, 116 concept of habitability on, 209, 214, 217, 219 diamictite, 117 92, 94 crystals, oldest, 92 differentiation, 108 early environment of, Cyanidium, 160, 164 diffusion-limited rate, 123 89–110, 93, 97 cyanobacteria, 125, 126, 127, Digital Speedometer evolution of habitability on, 133, 134, 141, 142, 162, exoplanet detector 115–28 164 system, 295 as evolving planet, 132–47 Cyclops Report, The, 292 dinitrogen, 185, 186 expanding the deﬁnition of, Dione, 202, 203 235–7 Darwin, Charles: direct imaging, 16, 235, extraterrestrial material voyage of, 5–6, 17, 18 242–3, 245, 254–6, 264, imported to, 63–4, 67, 90 see also evolution, 267 ﬁrst billion years of, 48–67 Darwinian; natural diseases, 31 geological “Dark Ages” selection dissolved inorganic carbon period of, 133–4 Darwin mission, 245 (DIC), 54 geological “Middle Ages” Davies, Paul, 25–45 Doppler method, 16, 182, 197, period of, 134–41, 147 Dawn Misson, 220–1 233–4, 252, 264, 272, 300 geological time scale of, 118 Death Star, 76 double helix, 41, 43–4 life on, see terrestrial life Debengda Formation, 142 Doushantuo Formation, 142, Mars analogs on, 157–65 Decadal Survey, 194 144 –Mars system, 37

310 Index

Earth (cont.) geysers on, 8 Europa, 177, 218, 250 metabolism on, 48–67 South Polar Terrains (SPTs) age of, 183–4 microbial habitat of, 94–9, of, 209, 212 atmosphere of, 184 98 endolithic organisma, 103 characterizing perceived as exclusive energy sources: environments of, 185 domain of life, 5 for building biomass, 48–9 habitability potential of, spectra of, 240, 267 chemical, 6, 10, 181 176–7, 178, 179–85, 181, Titan compared to, 15, on Earth, 6 201, 202, 215, 216, 217 185–6, 188–9, 190–1, as life essential, 10, 15, 89, as large, icy satellite, 202 193–4, 196 94, 101, 175, 184, 205–8 mapping seafloor of, 182–3 topography of, 51–2 light as, 6, 10, 48 as potential Class III habitat, uniqueness of, 52 for microbial metabolism, 180–1 Venus vs., 232 54–5 proposed future mission to, Earth-like planets, 8, 9, 231–7, oxidation as, 48 8, 181–5, 194–5 262 environment: searching for biosignatures candidates for, 238–9 of early Earth, 89–99 on, 185 definition of, 233, 233 as setting for early Earth subsurface ocean on, 8, detection techniques for, life, 12, 13, 99–100 181–5 233–5 see also extreme surface composition and finding biosignatures on, environments chemistry, 183 239–45 enzymes, in progenote, 61–2 surface/exosphere/ incidence of, 238–9, 290 Eocene Era, 161 magnetosphere nomenclature associated epilithic organisms, 103 interactions of, 184–5 with, 232 EPOXI mission (NASA), 240 surface morphology and Earth twins (Earth analogs), Epsilon Eridani, 286 dynamics of, 183–4 233, 244–5, 262 Equinox Mission, 220 Titan compared to, 194 eclipses, 16, 234 Eris, 203, 217 European Extremely Large Eemian Ice Drilling Project, erosion, 102, 133 Telescope, 264 161, 162 of Mars atmosphere, 171–2 European Southern Eemian Period, 162 error catastrophe, 61 Observatory, 253, 264 EJSM mission (Europa Jupiter ESA (European Space Agency), European Space Agency (ESA), system mission) 186, 194–6, 269, 278, 186, 194–6, 269, 278, 295 (proposed), 194–5 295 euxinia, 136 electricity, in origin of life, 63 ESPRESSO instrument, 264 evolution: electromagnetic fossil etching, 102–3 cosmic, 9 radiation, 266 ethane, 15, 241 Darwinian, 10, 12, 17, 26–8, elongation factors (EFs), 31 eubacteria, 31 32, 39–40, 41, 43–4 embryos, fossilized, 143–5 Euglena, 160 human, 291 embryos (planetary), 74–6 Eukarya, eukaryotes, 12, 57, non-Darwinian chemistry growth of planets from, 76, 122, 132, 139, 141–3, 142 in, 39–41 83 cell formation in, 134 in onset of life, 11, 12 Enceladus, 179–80, 193, 196, differentiation in, 146 reproduction vs., 26–7 201, 203, 203, 210, 213, in Mars analogs, 162, 164 theory of, 6, 30 220 metabolism in, 49, 58–9 exobiology, 7

Index 311

Exoplanet Characterization exopolysaccharides (EPS), 160 origins of terrestrial life in, Observatory (EChO), 278, Expedition Fiord, 161 5, 9, 14 279 exploration: philosophical implications Exoplanet Data Explorer, 258, and example of Earth, 29, of, 6, 18–19 261 37–9 potential for colonization Exoplanet Orbit Database, 258, and example of Mars, 32–7 in, 289 261 in life theory formation, 28, SETI in, see Search for exoplanet revolution, 268–9 30, 32–9 Extraterrestrial exoplanets (extrasolar external occulter, 245 Intelligence (SETI) planets), 81, 82, 256, 258, extrasolar planets, see social implications of, 6, 18, 261 exoplanets 301–2 anticipated developments extraterrestrial intelligence, strategies and search in search for, 263–4, search for, 3, 17–18 specifics in, 291–302 277–80 extraterrestrial life (ET): tools for, 292–3 atmospheres of, 242–4, communication with, 6 extreme environments, 6, 9, 266–80, 273 definitive signs of, 7, 16–18 32, 94 detection of, 8, 15–16, 76, extinct, 289 desert, 164, 172 250, 251–6, 253 hypothetical non-water exploration approaches for, distant, massive, 257 based, 189, 190 38–9 distribution of parameters intelligent, 291 of microbes, 48 of, 258–9 potential sites for, 14–16, on moons, 193 diversity of, 256–60 122, 288–9 non-standard life in, 38 eclipses on, 234 primitive, 25–45 terrestrial adaptation to, impediments in discovery as radically different from 146 of, 254, 258, 259, 260, terrestrial life, 6, 7, 9–10, extremophiles, 287 263–4 14–15, 19, 175, 189–90, limits of, 38 low mass, 260–4 266–8 terrestrial, 6, 9, 14, 38, 291 molecular signatures in signals from, 292–3, 300–3 water and, 15 spectra of, 273–7 terrestrial life as model for, most Earth-like, 262 10, 14, 19, 30–1, 146–7, Faint Young Sun, 119–22, multi-planet systems of, 233 119–22, 158, 158, 169, 170 260–2 extraterrestrial life (ET), Fairén, A. G., 158, 217 number of, 15, 16, 252 search for: Fennel, K., 127 past, present, and future astrobiological basis of, 9 fermentation, 125 facilities in science of, 277 attempted communication Fermi, Enrico, 289 preliminary statistics for, in, 16, 286–303 55 Cnc e (planet), 269 262–3 challenges in, 17 51 Peg (star), 15, 252, 257, 269 review of known, 250–64 compared to Darwin’s Firmicutes, 160, 164 searches for habitable, voyage, 5–6 Fischer Tropsch, 96 231–46, 250–64 Drake equation in, see Drake Fitz–Randolph telescope, 295 and terrestrial planet Equation Flagstaff, Ariz., astrobiology formation, 84 funding of, 8 symposium at, 7 thermal and physical null results of, 18, 286, “follow the energy” principle, nature of, 254 289–90 10

312 Index

fossils, 30, 105, 142 Galileo spacecraft, 8, 176, 180, Gilmour, I., 219 animal, 51 182, 183 GJ 436b (planet), 270 biosignatures in, 103–4, Gammaproteobacteria, 160, GJ 581d (planet), as potentially 127, 141, 143–5 161 habitable, 269, 278 chemical components of, Gamma Ray and Neutron GJ 1214b (super-Earth), 269, 100 Diffraction instrument, 272 eukarotic, 142–3 221 glacial pavements, 117, 119 evidence of metabolism in, Ganymede, 176, 178, 178, 179, glacial till, 117 100 192, 194–5, 250 glaciation, 118 extraction and Gas Chromatograph and Mass on Mars, 205 identification of, 102–3 Spectrometer (GCMS), 34, Paleoproterozoic, 117, 119, forests, 161 35, 188, 191 125 fuel, 121n gas giant planets, 16, 254, 257, Precambrian, 127–8 history recorded in, 132–3, 261, 269 Proterozoic, 139, 140, 145 159 formation of, 74, 76, 77, glaciers, rock record found in, living, 39 79–83 117, 119 microbial, 53, 57–9, 67, habitability on moons of, Gliese 436b, 260, 261 99–104 175–97, 176 Gliese 581, 262 microorganic, 7, 35–6 low-mass planets vs., 263 Gliese 1214, 261 mineral preservation moons of, 288–9 Global Positioning Systems process of, 101–2, 132 in rocky planet formation, (GPS), 295 molecular, 57–9 84 glycolysis, 49 molluscan, 116 see also hot Jupiters; specific gneisses, 91, 92, 95, 108 physical structure of, 100–1 planets Goldblatt, C., 123n trace, 132 Gaucher, E. A., 31 granites, 52 fractals, 120 genes: gravitational microlensing, fractionation, 10 ancestral, 31 235 “mass-dependent” vs. of LUCA, 59–60 gravity: “mass-independent,” 135 in progenote, 60–1 in planet formation, 75–6, Frank, E. A., 204 sequencing, 31 79, 80, 84 frequency comb, 234 “genes first” hypothesis, 64 in planet migration, 78–80 frequency compression, 293 genetic code: Great Oxydation Event (GOE), freshwater environments, 141 in DNA, 12 55–6 Funes, José Gabriel, 4 proto-ribosomes in, 13 atmospheric composition fungal hyphae, 104 in RNA world, 11 before, 122–8 genomes: competing hypotheses for, GACTZP synthetic genetic microbial metabolism 126–8, 134 system, 44–5 recorded in, 51–67 consequencers for life of, Gaia mission (ESA), 269, 295 replication errors in, 61 134–6 Gaidos, Eric, 132–47 geological record, 30, 51–6, “great silence,” 18, 290 galaxies, 231, 246 90–1, 92, 94, 96, 100, 102, Green Bank, W.Va., 286, 287, number of, 290 109, 115–19, 132–3, 135 290 see also Milky Way galaxy “gestaltian” issue, 10 greenhouse effect, on Mars, Galilei, Galileo, 250 Giant Magellan Telescope, 264 165–7, 168–70, 173

Index 313

greenhouse environment, 117, HAT-P-7b (planet), 270 Hoyle, Fred, 27 120, 121n, 140, 160–1 haze: HR 8799 (star), 256, 256 greenhouse gases, 120–1, organic, 120, 125 Hsieh, H., 213 123n, 125–6, 139–40, 170, on Titan, 188–9 Hubble Space Telescope, 8, 74, 241 HD 10180 (star), 261 184, 221, 242, 243, 270, in GOE, 126 HD 40307 (star), 261 271, 272 Greenland: HD 69830 (star), 261 human beings: ice drilling in, 161, 162 HD 97658b (planet), 278 connectedness of, 299 old rocks in, 52, 90, 92, 95, HD 189733b (planet), 238, 243, drive toward knowledge of, 100, 101, 103, 104 271, 272–4 5, 17 Ground Penetrating Radar HD 209458b (hot Jupiter), 254, see also terrestrial life (GPR), 182 272, 274, 275 Huronian glacial interval, gypsum, 164 heat retention and transfer, 119, 127 Gypsum Hill, 161 207–8 Huygens Aerosol Collector heavy metals, 159–60 and Pyrolyzer (ACP), 188 habitability, 209–19 helium: Huygens Atmospheric criteria for, 175, 262, 269 -hydrogen fusion, 120, Structure Instrument of Earth, 92, 93, 94 250–1 (HASI), 192 of small bodies, 201–22 in planet formation, 74, Huygens Descent use of term, 92 253 Imager-Spectral habitable planets: hematite, 160 Radiometer (DISR), 193 definition of, 232, 233 Herbert, Frank, 172 hydoxyl free radical, 127 formation of, 83–4 Hesperian (volcanic) Period, hydrocarbons, 8, 189 SETI’s catalog of, 295–7 158, 167, 172 hydrogen, 8, 13–14, 122, 176, habitable zones (HZ), 8, 175, Earth analogs for, 160–2 209, 286 233, 235–7, 236, 253, 289, heterotrophs atmospheric, 122–5, 260 290 (“other”-feeding), 48, 164 in ET transmission, 286 definition of, 233 high-resolution cameras, 184 -helium fusion, 120, 250–1 super-Earths close to, 262 Hill sphere, 79 in planet formation, 74, Hadean Eon, 9, 52, 53, 102, Himalayas, 52 253 108, 118 HNOPS (essential elements), in respiration, 121–2 Haldane, J. B. S., 63 89, 94 hydrogen bonding Halley’s Comet, 245 Hooke, Robert, 36 complementarity, 41, Hamamatsu fast hopanes, 101 43–4, 43 photomultipliers, 297 horseshoe orbits, 78 hydrogen cyanide, 189 Hand, K. P., 180 hot Jupiters: hydrogen peroxide, 180 HARPS (ESO) survey, 197, 252, atmosphere of, 276 hydrogen sulfide, 13 253, 263–4 density of, 257, 274, 277 hydrothermal systems, 13–14, Harvard All-Sky Optical SETI detection of, 243–4, 254, 38, 48, 54, 61, 93, 97, 106, Observatory, 298 257, 258–9, 269, 271, 272, 117, 139, 215 Harvard University, OSETI at, 274 on asteroids, 205–6, 208–9 295, 297 formation of, 81–2, 257, on moons, 180–1, 193, 214 Hat Creek Radio Observatory, 269 in origin of life, 63–5, 67, 295 orbits of, 81–3 92, 94, 96, 99, 159

314 Index

hydroxyl radicals, 122 IRIS (Infrared Interferometer Kepler Space Telescope (NASA), Hymenobacter, 164 Spectrometer), 267 234, 238 iron, 13, 89, 125, 139, 141–2, kerogen, 54, 67 IAU Telegrams, 301 145, 159–60, 205 Kharecha, P., 124 Iberian Pyritic Belt, 159–60 iron silicates, on Mars, 8 Kirschvink, Joseph, 115–28 ice, 8 isotopic fractionation, 133, Kitty’s Gap Chert, 98, 104, 105, on asteroids, 203–9 171, 191 106 on larger planets, 76, 79 ISS (Cassini Imaging Science Klingons (characters), 28 as Mars analog, 162, 165 Subsystem), 187 Knoll, Andrew, 132–47 on moons, 176–7, 176, 177, Isua Greenstone Belt, 92, 95, Kocuria, 164 178 104, 108, 126 komatiites, 96 oldest known, 162 Itsaq Gneiss Complex, 52 Koshland, Daniel, 25–6, 28, 36 ice ages, see glaciation Kuiper Belt, 216, 221, 222 icebergs, 117 James Webb Space Telescope ice cores, 162 (JWST; NASA), 17, 244–5, Lafleur, L. J., 6 ice giants, 77 244, 264, 277 Lajolo, Giovanni, 3–4 advances in detection of, jarosite, 160 Lakhanda group, 142 260–3 jellyfish, 145 Laplace, Pierre Simon, 269 ice house environment, 117, Jewitt, D., 213 laser altimeter, 183, 184 140 Johnson Space Center (NASA), Last Universal Common icy satellites, habitability of, 35 Ancestor (LUCA), 12, 14, 176, 177, 178, 209–13 JUICE mission (proposed), 195 145 impact erosion, 171 Jupiter, 15, 74, 84, 90, 176, gene content of, 59–60 Impey, Chris, 5–19, 286–303 178, 205, 234, 250, 253, metabolism and, 49, 51 Infrared Interferometer 254, 256, 256, 269 in microbial metabolism, Spectrometer (IRIS), 267 magnetic field of, 184 65–7 infrared light spectra, 180, mass of, 81 microbial metabolism in, 238, 240, 272–4, 275 moons of, specific moons 57–60 Infrared Space Observatory, orbit of, 260 progenitor of, 60–2 191 Jupiter Europa Orbiter (JEO), Later Heavy Bombardment, INMS (Cassini Ion and Neutral 195 108, 109 Mass Spectrometer), 187, “late veneer,” 90 191, 212, 220 Kalahari Manganese field, 126 Lederberg, Joshua, 7 intelligence, extraterrestrial, Kant, Immanuel, 269 Leptospirillum ferrooxidans, 160 3, 17–18, 25 Kasting, James, 115–28 Leuschner Observatory, 295 intelligence, technological, Keck–HIRES team, 262 Levin, Gilbert, 34 145, 146 Kepler 10b (planet), 262, 269 Lick Observatory, 295 intelligent design, 40 Kepler 11d, e, and f (planets), life: interferometers, 245, 256, 267 269 being alive vs., 26 International Astronomical Kepler mission (NASA), 8, 16, building blocks for, 11 Union, 301 84, 197, 233n, 238–9, 254, character of, 29 Internet, 301 255, 262, 263, 269, 270, definition of, 9–10, 25–30, invertebrates, marine, 137 290 36, 266 ion mass spectrometers, 103 Kepler’s law, 75 differentiated, 108, 146

Index 315

diversification of, 11, 133, timing of, 100, 108 magnesium sulfate, 160 135, 143–5 two competing theories of, magnetic field: early evolution of, 9, 11–13, 63–4 Earth’s, 96 63–4, 99–109, 135 light: Martian, 160–1 essentials for, 10, 13–14, 15, curves, 273 magnetite, 64, 121 26–7, 33–4, 89, 90, 94, 95, as energy source, 6, 10, 48 magnetometers, 183 100, 241 infrared, 17 magnetospheric plasma, 184 expanded view of “Limits of Organic Life in Makemake, 203 requirements for, 241 Planetary Systems, The” Makganyene glaciation, 119, future of, 9 (Baross et al.), 241 119, 126, 128 historical context of, 30–2 Lindblad resonances, 78 manganese, 13 key elements for (CHNOPS), lipids, 101 Manhattan, Dr. (character), 25 180 biomarkers in, 133 mantle, Earth’s, 89, 90, 91 signatures of, 10, 16, 25 lipid synthesis, 58 Mariner spacecraft, 267 survival strategies for, 94 liquid water: Mars, 74 as system, 26 on Earth, 67, 89, 90, 92, 94, atmosphere of, 158, 160–1, terracentric view of, 28, 33, 115, 116 165–73, 170, 191 241 on Enceladus, 8, 212 attempts to detect life on, theory-based definitions of, on Europa, 182–3 7–8, 14, 17, 32–5, 110 9–10, 25–45 in Hadean Eon, 52 Cauldron theory of, 172 three domains of, 58–9 on surface of Mars, 8 conflicting views of, 158–9 vs. thriving, 94 on Titan, 15 crust of, 52 see also animals; lithification, 102 debate over life-detection extraterrestrial life; lithopanspermia on, 33–5, 172–3 human beings; terrestrial (transpermia), 37 determining habitability of, life lithosphere, 210 157–73 life, origin of, 11–13 Lomagundi excursion, 139 early speculations about, bottom up vs. top down Lost Hammer Spring, 161–2 157 approach to, 11–12 Love number, 209 Earth analogs for, 162–5 Earth as appropriate setting Lovis, Christophe, 250–64 –Earth system, 37 for, 89–110, 232, 291 Lowell, Percival, 157 as example of life theory effect on atmosphere of, Luna 3 probe, 267 formation, 32–7, 38 123–5 Lunine, Jonathan, 201–22 extreme environment of, electricity in, 63 32, 165–72 extraterrestrial material in, McCord, T. B., 208, 213 geological ages of, 157–65 63–4, 67, 90 McKay, David S., 7, 8, 35–6 human habitation on, 18 mechanisms for, 64–5 McKinnon, W. B., 218 lack of plate tectonics on, metabolism-first vs. mafic rocks, 96 91 replicator-first hypothesis magic, technology compared liquid water on, 8, 158–9, in, 12–13 to, 292 160, 166–8, 169–71, mineral catalysts in, 12–13 magma, 89–90 172–3 in oceans, 63–4, 138–9, magnesite, 214 low gravity of, 171 141–6 magnesium silicates, on Mars, meteorites from, 35–7 settings for, 13–14, 63–4 8 missions to, 267

316 Index

Mars (cont.) on Mars, 8 Milky Way galaxy: temperature on, 165–7, 166, in methanogenesis, 123–5 age of, 286, 292, 299, 303 170 on Titan, 185–7, 188–90, number of stars in, 296 see also Viking Mars mission 194, 195–6 possible planets in, 8, 231, “Mars as the Abode of Life” methane-based life, 189–90 250, 252, 291 (Lowell), 157 methanethiol, 241 star formation in, 84 Mars environmental methanogenesis, 123–5, 140, stars in, 73 simulator, 162 189, 240, 241 universe beyond, 246, 290 Mars Exploration rovers, 8 methanol, 204, 214, 219, 241 Miller, Stanley, 12 Mars Global Surveyor orbiter, microbes: Miller–Urey experiment, 63, 8, 161, 166, 240 as alien organism on Earth, 188 Mars Odyssey orbiter, 8 38–9 Mimas, 211 Mars Science Laboratory, 14 in Allan Hills Meteorite, minerals, catalytic, 13–14 mass fraction, 209, 210, 218 35–6 Minniti, Dante, 250–64 mass–semi-major axis plot, in Axel Heiberg Island, 161 Miranda, 203, 212 258–9, 258 early Earth environment of, mirror life, 39 Mayor, Michel, 252, 269 94–9, 98 mirror soup, 39 melting, 6 fossilized, 53, 57–9, 67, mitochondria, 134, 141 melt layers, on Mars, 166–7 99–100 modulation schemes, 302 Meridiani Planum, 160 habitats of, 48, 139 Mojzsis, S. J., 204 metabolism: hydrogen-based, 8 molecular “clocks,” 143 anaerobic, 123–5, 141 as majority terrestrial molybdenum, 13, 135, 136, extant vs. early, 65–7 species, 38 139, 143 hydrogen-based, 8 survival strategies of, 48–51 Moon: as life essential, 33–5 microbially induced cratering on, 52 proto-, 12–13 sedimentary structures crust of, 52 in RNA world, 62–3 (MISS), 53, 67 effect on Earth of, 90 terran, 48–67, 49, 53, 65, 66 microbial mats, 53, 55, 97, 98, formation of, 83, 90 metabolism ﬁrst hypothesis, 99, 104, 105–8, 107, 109, missions to, 267 13, 64 132, 142 moons: metamorphism, 133, 140 microbial metabolism, 48–67 exploratory missions to, meteorites, 30, 90 molecular fossil record of, 179 amino acids in, 64 57–9, 100 future explorations of, as building blocks for life, rock record of, 51–6 194–7 11 microgradiometer, 183 habitability issues for, “meter-sized barrier,” 74–6 microorganisms, 9, 106 176–9 methane, 13, 15, 239, 241, 243, chemoorganotrophic, 97, icy, 176–7 271, 272–3, 273, 274 99–100, 101 large, habitable, 175–97 as biomarker, 17, 161, 219, traded between Earth and position and temperature 221 Mars, 37 of, 204 as greenhouse gas, 120, 122, and UV radiation, 99 property table for, 203 125–6, 140 mid-infrared (MIR) spectra, as sites for ET life, 6, 288–9 in hydrogen-based 240, 273–4, 275 Moore’s Law, 297 metabolism, 8 migration, 78–9, 80–2 Morrison, Philip, 287, 299

Index 317

mountain building, 52 New Horizons Mission, 218, planets with, 176 Mstars,260, 269, 278, 290 221–2 Proterozoic, 135–6 habitable zones of, 236–7, Nice model, 205 redox state of, 122 244, 262 nickel, 13, 89 reducing of, 52 Mullen, G., 120 Nimbus 3 satellite, 267 on small bodies, 211–12, multiple striated cobble, Nimmo, F., 219 214, 217–19 117 nitrate, 134 Odishaw, H., 7 mutations, 26–7, 44 nitrite, 134 olivine, 13, 52, 64 Mycrobacterium, 160 nitrogen, 55, 192, 219, 221 Oparin, A. I., 63 Myhrvold, Nathan, 295 isotopes, 10, 13, 159 Opportunity rover, 160 in Mars atmosphere, 168 orbital migration, 257 Nama Group, 144 Nitrospira, 160 orbits, planetary: Namibia, 144 nitrous oxide, 17, 140 eccentric, 81–3, 207, 258, Nanedi Vallis, 8 Noachian (warm and wet) 259 nanobacteria (nanobes), 39 Period, 157–8, 161, 167–8, of exoplanets, 257, 258, 259 NASA Astrobiology Institute 171–2 formation of, 78–80 (NAI), 7, 8, 9 Earth analogs for, 159–60 of gas giants, 81–3 National Academy of Sciences, North Pole Dome, as Mars periods of, 253 287 analog, 159, 162 of rocky planets, 83 Space Studies Board of, 7 nuclear fusion, 73 Orcas, 203 National Aeronautics and nucleic acids, as catalysts for organic acids, 8 Space Administration metabolism, 62–3 organic carbon burial, 142–3, (NASA), 7, 194, 196, 220 nucleosynthesis, 266 146 definition of life by, 26–8, nucleotides, 43–4, 43, 49, 49, organic haze, 120, 125 41 65 organic solvents, 8 funding for, 8, 195 Origin of Species, The (Darwin), see also specific missions Oak Ridge Observatory, OSETI 6 National Radio Astronomy telescope at, 295, 297 Orion Nebula, 73 Observatory, 286 obliquity cycle, 167, 169, 172 OSETI (Optical Search for natural history, 29 observation, in life theory Extraterrestrial natural selection, 6, 12, 13, 17, formation, 28–9, 31 Intelligence), 293, 294–5, 145 oceans: 297 Nature, 287 deep, 38, 48, 109–10, 135–6 other Earths, see Earth-like Naval Observatory, U.S., 295 diversification of life in, planets Navarro-Gonzalez, R., 163 133, 134–5 oxidants, 122 Near Infrared Mapping early, 93, 95, 96 oxydation: Spectrometer (NIMS), early life in, 63–4, 138–9, of Earth atmosphere, 55–6, 183 141–6 67, 89, 91, 97 near-infrared (NIR) spectra, magma, 89–90 as energy source, 48 240, 272–4, 275 mapping of, 182–3 in redox process, 48, 209, Neptune, 15, 77, 79, 216, 219, on moons, 180–5, 186, 239–41 234, 253, 254, 260, 263 191–3, 194 second event of, 142–5 neural networks, 145 oxygen stabilization and see also Great Oxydation Newfoundland, fossils in, 145 regulation in, 53, 136–8 Event

318 Index

oxygen, 13 phyllosilicates, 157n, 159 plankton, 51, 109 atmospheric, 53, 120, 122–8, PICERAS definition of life, 26, plate tectonics: 134, 239–41 28–9, 36 in Earth’s topography, 51–2 as biomarker, 17 Pierrehumbert, Raymond, as energy source, 15 isotopes, 10, 116–17 157–73, 170 origin of, 91 as life essential, 89, 107, Pilbara Craton, 53, 54, 95, 98, in origin of life, 14, 91–2 145, 147, 175–6 99, 100, 104, 105, 106, 108, Plato, 291 in ocean, 138–9, 141–4 109, 159 Pluto, 201, 202, 218 in photosynthesis, see Pilcher, C. B., 241 habitability potential of, photosynthesis, oxygenic Pinnularia, 160 203, 219, 221–2 Proterozoic rise in, 134–6, placozoans, 145 reclassification of, 269 140–1 Planetary Protection officer, 7 polymerases, 58 rise of, 115–16 planetesimals, 202, 213, 215, polymers, 100 stabilization and regulation 221 Pongola glaciation, 119, 127 of levels of, 136–8 belt, 216–17 Pontifical Academy of see also oxydation growth of planets from, 76, Sciences, 3–4 oxygen whiffs, 127 83, 89 potentially habitable planet, ozone: hydrated, 83 definition of, 232, 233 atmospheric, 120, 123, 267 see also asteroids prebiotic chemistry, 29 as biomarker, 17, 240–1 planet–planet scattering, 82 predation, 134, 145 planets: present atmospheric level paleogenomics, 31–2 accretion of, 52 (PAL), of oxygen, 56, 135, paleosols, 56, 121 beyond Solar System, see 137 perchlorates, 163–4 exoplanets pressure: permafrost, 94, 161–2, 165 definition of, 232, 250 in melting, 6 Phaeton, 215 dwarf, 213, 216, 218–19, temperature as function of, Phanerozoic Eon, 53, 107, 118, 269 274–5 135 Earth-like, 290 primordial soup, 12, 30 Phoebe, 209, 217 formation of, 8, 73–84, 77, mirror, 39 Phoenix mission, 161, 163–4, 80, 251, 269 Princeton University, 295 165 giant vs. terrestrial, 269 progenote: phosphorus, 13 measuring mass of, 236 definition of, 62 photons, in ET measuring of, 253 vs. LUCA, 60–2 communication, 293, migration of, 78–84, 90, 269 Project Ozma, 286, 287 294–5, 300 physical and chemical prokaryotes, 122n, 134, 160 photosynthesis: identities of, 268 proteins: anoxygenic, 14, 97, 99–100, search for ET life on, see catalysis, 50 105, 106, 109, 125, 162, extraterrestrial life, as life essential, 36–7, 38, 164 search for 40, 64 oxygenic, 17, 33, 53, 55, 67, stars vs., 250–1 sequencing, 31 94, 97, 98, 99, 107, 109, transiting, 234, 243, 253–4, synthesis, 11, 58, 59, 60 122–3, 125, 126, 127–8, 274 use of term, 62 134, 136–7, 147, 242 see also specific planets and Proterozoic Eon, 53, 107, 118, Photosystem-II, 127, 147 types of planets 132–47

Index 319

climate in, 139–41 redox (oxydation and Rio Tinto, 170, 172 life in, 138–9 reduction) processes, 48, extreme environment of, 32 oxydation in, 134–8, 140–1 209 as Mars analog, 159–60 Proterozoic era, 119 searching for biosignatures “RNA ﬁrst” hypothesis, 40 protocontinents, 95, 108, through, 239–41 RNA world, 11, 12, 32, 39 109 reef systems, 51 Martian, 37 proton probes, 103 refractory elements, 76 metabolism in, 62–3, 66–7 protoplanetary disks, 80 regolith, 205 pre-biotic chemistry before, composition of, 76 religion: 63–5 cooling of, 78 ET life and, 18 Robuchon, G., 219 in gas giant formation, 81, and science, 5 rock mass fraction, 211 257, 259 replication: rocks: in planet formation, 8, in LUCA, 60 basaltic vs. continental, 52 73–9, 251 mutations in, 26–7, 44, history recorded in, see in rocky planet formation, 61 geological record 83 in progenote, 60–1 isotopic life signatures in, proto-ribosomes, vs. replicator-ﬁrst hypothesis, 100–1 replicating RNA, 13 13 Mars analogs in, 164 pulsars, 15, 235 replicators, 11, 12 oldest, 52–3, 91, 92, 100 pulsar timing, 235 reproduction: on Titan, 193 pyrite, 56, 136 as life essential, 26–7 traded between Earth and as catalyst for organic replication vs., 26–7 Mars, 37 synthesis, 13 in synthesis, 43–4 volcanic, 95–6 pyroxine, 52 respiration, 122, 146 –water interactions, 8 oxydation and global, 134, see also fossils; sedimentary Q (character), 27–8 137–8 rocks Quaternary glacial interval, resting stages, 145 rocky (terrestrial) planets, 16 127 resurfacing, 209, 210 formation of, 74, 76, 77, Queloz, Didier, 252, 269 ribonucleic acid (RNA), 31, 41, 83–4 43, 57 plate tectonics and size of, Radial Velocity, 197 in LUCA, 58–9, 60 91 radial velocity (RV) technique, messenger, 40 potentially habitability of, 232, 234, 252–3, 253, 254, as metabolic catalyst, 62–3, 83, 146–7 258, 260, 261, 262–4, 274, 66–7 see also Earth; Mars; Venus 290–1 primitive life as dependent Rodinia, breakup of, 135, 145 radioisotopic decay, heat on, 32, 37, 40 Rosing, M. T., 52–3, 95, 121 from, 205–6, 206, 209–11, ribosomal, 56–9 Ruiz, J., 218 211, 214, 221 as self-replicating, 11, 12, Russian Space Agency radio telescopes, 293 13 (Roskosmos), 195 Ranger spacecraft, 267 ribose, 49 rybozymes, 62 “Rare Earth” hypothesis, 291 ribosomes, 31, 35, 36–7, 38, Rye, R., 121 Raymond, Sean N., 73–84 56–9, 57, 60 recrystallization, 52 Rich, Alex, 40 Sagan, Carl, 63, 120 “red edge,” 242 rifting, 52 salts, in melting, 6, 214

320 Index

satellites, small, icy, 202, 210, sedimentary rocks: Snowball Earth, 119, 126, 140 211 formation of, 51 snow line, 76, 83, 259 Saturn, 74, 90, 196, 253, 254, history recorded in, 132–3, sodium chlorate, replication 260 135–6, 143 in, 27 moons of, 8, 15, 120, 176–8, microbial metabolism solar extreme ultraviolet flux, 195–6, 202, 206, 209, 213, recorded in, 51–6, 67 171 216, 217 oldest preserved, 53, 95 Solar System: Schiaparelli, Giovanni, 157 transport and deposition in, as atypical, 81, 259–60 Schleyden, M. J., 36 51–2 formation of, 77, 205 Schmidt, B. E., 216 Sedna, 203 as unique in Universe, Schmidt telescope, 238 Segura, T. L., 172 268–9 Schwann, Theodor, 36 seismometers, 182 solar wind, 91 Schwartz, R. N., 294 self-sustainability, as life Sorondo, Sanchez, 4 science fiction, theories of life essential, 26, 28, 45 Sotin, C., 208, 213 from, 27–8 Sephton, M. A., 219 Soviet Union, Sputnik Science in Space (Berkner and SERENDIP projects, 293–4 launched by, 7 Odishaw), 7 serpentine, on Mars, 8, 64 spacecraft: scientific method: serpentinization reactions, 8, sterilization of, 7 establishment of, 5 208–9 see also specific vehicles value of errors in, 3 SETI@home, 293–4, 299 Spain, 159 seafloor spreading, 14 setiQuest, 299 spectrographs, 252 Seager, Sara, 231–46 shadow biosphere, 38 spectrometers, 34, 35, 103, Search for Extraterrestrial Sheldon, N. D., 121 183, 187, 188, 191, 212, Intelligence (SETI), 17–18, Shock, E. L., 218 300 25–6, 287, 288, 291–3 Shostak, Seth, 292 Sphingomonas, 164 analysis of data from, 297 Siberia, fossils in, 142 Spitzer Space Telescope, 270, as archeology of the future, siderite, 121 271, 272 299–300 silica, 96, 102–4, 105, 106, 179, sponges, 143, 145 catalogs of, 296 180, 182–3, 194 springs, 160, 161 dedicated observation sites silicates, 89, 176, 179, 180, Sputnik launch, 7 of, 293–8 182–3, 194, 215, 217 sputtering, 183, 184 eliminating hoaxes in, 300 16S ribosomal RNA (rRNA), starlight, 250 established as discipline, 57, 59 suppression of, 245, 254 287 65 Cybele, 203, 205, 214 stars: funding for, 295, 301 size complementarity, 41, convective zones of, 82–3 null results of, 18 43–4 dead neutron, 235 optical (OSETI), 293, 294–5, small bodies: dwarf, 16 297 future exploration of, exoplanets and, 250–1, 256, projected response to ET 219–22 259, 263–4, 263, 256 contact through, 300–2 geophysical evolution of, formation of, 73–4, 77, 289, signals in, 292–3, 302–3 210 290 world involvement in, habitability of, 201–22 low-mass, 236–7, 244 298–9 habitable, 209–19 number in Milky Way, 296

Index 321

planets vs., 250–1 super-Earths (telluric planets), telluric planets, see Sun-like, 16, 237, 238, 243, 15, 91, 158, 196–7, 236–7, super-Earths 244, 267, 286, 289 243, 253, 259, 261, 278 temperature: star spots, 237 close to habitable zone, 262 in Archean Eon, 116, Star Trek: The Next Generation, as common in other 117–22, 125 27–8 systems, 269 condensation, 76 Star Wars, 76 definition of, 234 effect of greenhouse gases Strelley Pool Formation, 53–4, detection of, 260–3, 264, on, 120–1 108 265, 278, 290 extreme, 6, 38 Streptomyces coelicolor, 60 discovery of, 234 as a function of pressure, stromatolites, 53–4, 55, 67, simulated spectrum of, 244 274–5 100, 107–8, 109, 132, 142, supernovas, 73, 290 and global respiration, 138 159 superoxide free radical, 127 heat from Sun, 206, 207 strontium, weathering synchrotron radiation, 103 of low-mass stars, 236 measured in, 140 synthesis: on Mars, 165–7, 166, 170 subduction, 52, 133 of life from scratch, 41–5 ocean, 96, 138 sublimation, 184, 214 in life theory formation, 29 plate tectonics and, 91 subsiding basins, 52 of new life forms, 29, 30 in Proterozoic, 139–41 sulfate, 134, 136, 138, 140, synthetic biology, 41–5 radioisotopic decay and, 157n 206, 207 sulfide, 56, 63–4, 125, 136, talc, 64 on small bodies, 205–8, 209, 140–1, 142, 145 Tarter, Jill, 286–303, 296 212 oxidation, 138–9 TED prize of, 299 for sustaining life, 205–8 sulfur, 13, 14, 121n, 135, 141, Tatel radio telescope, 286 10 Hygeia, 203 168 Tau Ceti, 286 terrestrial life: isotopes, 10, 143, 159 technology: as analog for ET life, 14, in microbial metabolism, advances in, 30, 252–3, 30–1, 233, 291 54–5, 56 254–6, 263–4, 267–8, astrobiological questions sulfur cycle, on Mars, 277–80 about, 6, 9 169–70 limits of, 17, 18, 29–30 carbon-based, 9 Summons, Roger, 48–67 in search for ET, 17–18, 288, Earth as appropriate setting Sun, 219 291–8, 301–3 for, 89–110, 93 age of, 286 see also specific technologies ET life radically different energy production of, 119 tectonism, 51–2, 133, 136, from, 6, 7, 9–10, 14–15, Faint Young, 170 145, 159 19, 175, 189–90, 266–8 heat from, 206, 207 on small bodies, 209, 210, as limited to one form, 32 sunlight: 212 metabolism in, 48–67 as energy source, 107, 125 telescopes, 8, 16, 17, 74, 182, molecular level of, 31 increased, 140 184, 202, 220, 221, 233, non-standard, 37–9 in oxydation, 55, 99 234, 238, 242–5, 250, origins of, 5, 9, 40–1, 109, suppression of, 245 254–6, 264, 267, 270–1, 179 supercontinents, breakup of, 277, 298 reconstruction of primitive, 135, 140 of SETI, 293–8 32

322 Index

Terrestrial Planet Finder organic solvent lakes on, 8 triangle of habitability, 180–1, mission, 245 possible sub-surface ocean 181 TES instrument, 166 on, 191–3 tricarboxylic acid (TCA) cycle, TESS (Transiting Exoplanet as potential Class IV habitat, 49 Survey Satellite) 185 Triton, 203, 218, 219 space-based survey, 237, potential for life on, 17, tungsten, 13 244 176, 179, 185–94, 202 turbidites, 95 Tghallophyca, 142 potential for water on, 15, Turnbull, M. C., 296 Tharsis, 172 176–7, 185–6, 187, 190, 24–isopropylcholestane, Themis family, 216 191–3, 192, 195–6, 205 143 thermal emission spectrum, proposed future missions 24 Themis, 205, 214 275, 276 to, 30, 195–6 2 Pallas, 221 thioesters, 12 temperature of, 189–90, habitability potential of, Thiomicrospira, 161 191 203, 215 Thirty Meter Telescope, 264 tonalite–trondjemite gneisses type I migration, 78, 80, 81 tholins (aerosols) on Titan, (TTGs), 92 type II migration, 80, 81–2 187, 188, 190, 193, 194 Toon, O. B., 120 Tibetan Plateau, 52 top down approach, 11–12, ultramaﬁc rocks, 96 tidal stress, 207, 211 239 ultraviolet (UV) radiation, 99, tides: top-of-atmosphere erosion, 106, 120, 123, 127, 135, heating from, 206–8, 207, 171 171, 180, 184, 188, 194, 209, 210, 212, 213, 218, torques, in planetary orbits, 202, 237, 241 219, 220, 267, 288 78 Umbriel, 202, 213 in orbital excentricities, 82, Townes, C. H., 294 universe: 207 trace fossils, 132 age of, 286 Tiger Stripes, 212 transit photometry, 238, ancient views of, 291 time perturbations, 235 251 galaxies in, 231, 246, 266 timing discovery method, 235 transit spectroscopy, 270–2 humans perceived as center Tinetti, Giovanna, 266–80 transit technique, 234, 235–7, of, 5, 245, 301–2 Titan, 241 236, 253–4, 257–8, 261, origin of, 9 atmosphere of, 120, 185, 267, 270–7, 270 uniform chemical 187–9, 192, 194 transmission spectrum, 243 components of, 266 compared to Earth, 15, translation, 60, 62 University Valley, as Mars 185–6, 188–9, 190–1, trans-Neptunian objects analog, 163, 165 193–4, 196 (TNOs), 201–2, 203, 206, unknown biosphere, 9 extreme environment of, 32 209 Upper Eleonore Bay Group, hydrogen lakes on, 189 habitability potential of, 142 interior models for, 192–4 216–19, 217 Uranus, 77, 79, 202, 213, 216, lakes on, 191 position and temperature 253 as large, icy satellite, 202 of, 204 orbit of, 260 organic chemistry on, properties table for, 203 possible habitability of, 187–91, 196 transpermia 212 organic factory and habitat (lithopanspermia), 37 Urey reaction, 140 of, 185–94 tree of life, 57–9, 57 Utopia Planitia, 162, 163

Index 323

Vatican Observatory, 4 rocks in, 95–6, 105 -rock interactions, 8, 95, vegetation, as biosignature, see also cryovolcanism 209 242 Voyager missions, 267 in sediment transport, 51 Venera spacecraft, 267 transition, 76 Venus, 74, 191 Waldman, I. P., 272 see also ice; liquid water atmosphere of, 168 Walker, J. C. G., 123, 124 water vapor, 120, 242, 267, 271, Earth vs., 232 warm Neptunes, 270, 274 274 extreme environment of, Warrawoona Group, 53, 54 Watson, James D., 41, 42, 43–4 32 Watchman, The, 25 weakly reduced atmosphere, missions to, 267 water: 123 Vesta, 220 anoxic, 141–2 weathering, 121, 136–7, 140 Vicuna,˜ Rafael, 157–73 on asteroids, 83, 203–9 weird life, 6, 28, 30 Vienna Pee Dee Belemnite fog as source of, 164 RNA-based, 32 (VPDB) standard, 54 and hot basalt, 13 Westall, Frances, 89–110 Viking Mars mission (NASA), as life essential, 10, 15, 83, Whipple Telescope, 298 7, 14, 30, 162–3 89, 90, 94, 95, 115, 122, White Cliffs of Dover, 51 life-detection experiments 175–9, 180, 193, 204–5, Woese, Carl, 60–1, 62 of, 33 233, 235, 241, 244 Wolf, E. T., 120 in life theory formation, liquid organic solvents vs., Wyeth telescope, 295 33–5 6 viruses, 9 living in vs. living on, 175–6 Xanthe Terra region, 8 volatiles, in Earth’s on Mars, 8, 158–9, 160, XO-1b (hot Jupiter), 274 environment, 89–90 166–8, 169–71, 172–3 volcanism, 51, 106, 107, 109, on moons, 176–9, 177, 178, Zaitsev, Alexander, 289 121, 210–11 185–6, 190, 191–3, zeroth order (corotation) on Europa, 182, 184 195–6 resonance, 78–9 as habitat for early other liquids in place of, zinc, 13 terrestrial life, 93, 97, 98, 241 zircon crystals: 104–5, 161–2 in photosynthesis, 55, 97, as nature’s time capsules, on Mars, 158, 159, 160–2 165 52, 115 on moons, 180 for potentially habitable oldest, 92, 95 outgassing from, 123 planets, 83, 290 Zolotov, M. Yu., 213