Astrobiology

Index

Acasta gneiss, 212–13
accretion, 49, 70, 76–85, 98, 270, 325, 330
Acidithiobacillus ferrooxidans, 251
acidophiles, 251, 254, 264–65
Adamala, Katarzyna, 169
Adams, Douglas, viii
adenine, 101, 117–19, 185
adenosine diphosphate, 122
adenosine triphosphate. See ATP
ADP, 122
aerobic metabolism: mitochondria, 237, 239
- origins, 228–30
AFP, 256–57
Akilia rock, 213–17
alanine, 106, 112, 133, 189, 192, 346
aldehydes, 108–10, 113–16, 120, 124, 133, 145, 310, 323
aldol condensation, 115
aldotetrose, 115
Aldrin, Buzz, 276–77
algae, 238, 242, 257–58
- lichen-forming, 257
ALH84001 (meteorite), 360–65
aliens, vii, 16, 178–79, 372–78
alkaliphiles, 264–66
alkenes, 131
alkynes, 131
Allen, Paul, 376
Allen Telescope Array, 376
alpha helix, 182, 256
α-particle and x-ray spectrometer, 291–92
Alphaproteobacteria, 235
Alpher, Ralph, 26–28, 61–62
Altman, Sidney, 160
Alvin (submarine), 246–47, 250–52
amino acids: assigned in genetic code, 191–96
- basics, 101–2
- chirality, 171–74
- in meteorites, 133
- peptide bonds, 101–2, 187
- prebiotic synthesis, 98–100, 106–12, 117, 128, 138, 147
- in proteins, 101–2, 180–82, 202
- in RNA world, 188–90
ammonia (NH₃): condensation in Solar nebula, 69–73, 77
- Darwin’s “warm little pond,” 142
- extraterrestrial sources, 131
- in outer Solar System, 302, 304, 314, 322–24
- prebiotic synthesis of amino acids, 98–104, 107–12
- prebiotic synthesis of nucleic acids, 117–21
- primordial atmosphere, 102–4
- properties, 18–20
- radical reactions, 108–9
- reducing environments
- volatile inventory, 66, 103–4
ammonium cyanide, 118–19
Andromeda galaxy, 27
animals: origins, 238–42
anisotropy, 36, 40
Antarctica, 257–60, 360–62, 367
anthropic principle, 47–51, 128, 170, 173, 374, 380
antifreeze, 256–57
antifreeze proteins, 256–57
antimatter, 30–32
anus, 238, 241
Apollo missions, 81, 276–77, 337
APXS, 291–92
Aquifex pyrophilus, 254–55
archaea: acidophilic, 264
- discovery of new domain, 209–11, 243
- fatty acid synthesis, 205–7
- genome sequence, 211
- halophilic, 222–23, 263–64
- histones, 231–32
- membranes, 205–7
- methanogenic, 357
- origin of eukaryotes, 180, 231–38
- relation to LUCA, 180, 203, 234
- rock-eating, 273–74
- in subglacial lake, 259
- thermophilic, 255, 269
- tRNA synthetases, 195
- used in mining, 251
Archaean eon, 212–13
archaebacteria. See archaea
Arecibo radio telescope, 371
argon (Ar), 79, 361
Aristotle, 140
Armstrong, Neil, 276–77
aromatic amino acids, 111–12, 202
Arrhenius, Gustaf, 213
Arrhenius, Svante, 142–44, 213, 279
Asgard archaea, 236
asparagine, 111, 192, 195
aspartic acid (aspartate), 100, 106, 112, 133, 192–95
asteroids, 23, 63, 66, 74–76, 80, 131, 216, 303–4, 359
Atacama Desert, 262
Athiorhodaceae, 223
ATP: produced in Krebs cycle, 229
- produced in photosynthesis, 225
- synthesis by ATPase, 223, 229, 265–66
- vestige of RNA world, 185, 203
ATPase, 223, 229, 265–66
autocatalysis, 145–46, 160
axial tilt, 95, 280

Bacillus alcalophilus, 266
Bacillus subtilis, 143, 201, 248
Backus, Peter, 376
bacteria: in clouds, 341
- compared to eukaryotes, 180, 231–38
- domain of life, 209–11
- drought-resistant, 260–64
- fossils, 217–21
- magnetotactic, 363–65
- membrane, 205–7
- minimal set of genes, 201
- nanobacteria, 364
- photosynthesis, 221–26
- relation to LUCA, 180, 203, 234
- ribonucleotide reductase, 199
- ribosome, 180, 186–87
- rock-eating, 366
- spores, 142, 277
- stromatolites, 219–21
- thermophilic, 255, 269
- tRNA synthetases, 195. See also cyanobacteria
bacteriorhodopsin, 222–23
Bada, Jeffrey, 107, 134, 138, 244
Banavar, Jayanth, 182
banded iron formations, 227
Bangiomorpha pubescens, 238
barite, 218
Barnard’s star, 57
barophiles, 266–68
Bartel, David, 163–65, 170
baryonic matter, 36–37
basalt, 217, 246–47, 271
Bean, Alan, 277
Becker, Luanne, 134–35
Benner, Steve, 116, 181–82, 199, 201–2, 364–65
Beresheet (spacecraft), 262
Bethe, Hans, 26, 46
“big bang” hypothesis, 28–41
Billingham, John, 372
biochemistry basics, 101–2
biodiversity, 180, 273
bioleaching (mining), 251
biomineralization, 241
blackbody radiation, 28–29, 38
Blackmond, Donna, 175
black smokers. See hydrothermal vents
Bogdanov, Alexander, 281
Boltzmann constant, 128
borates, 116
Bowyer, Stuart, 372
Brasier, Martin, 218
Breakthrough Listen, 376–77
Brock, Thomas, 250
Brook, Jim, 84
Brown, Mike, 78
Brownian motion, 3–4
buckyballs, 134–35
Budin, Itay, 169
Burroughs, Edgar Rice, 281
Butlerov, Alexander, 113–14

Cairns-Smith, A. G., 154–57
calcium (Ca), 16, 79, 154–55, 293
- borate, 116
- carbonate (limestone), 89, 107, 221
- hydroxide, 114, 116, 145
- sulfate, 291
Caldicellulosiruptor saccharolyticus, 251
Callisto, 302, 312–14, 324–25
- compared to Pluto, 324–25
- discovery, 302
- ocean, 313–14
- properties, 313–14
- topography, 313–14
Calvin, Melvin, 97–98, 225, 228, 373
Calvin cycle, 225
Cambrian, 215, 240
Cambrian explosion, 238–41
Campbell, William, 281–82
Canfield, Donald, 218
carbohydrates. See sugars
carbon (C): basis for life, 7–17
- buckyballs, 134–35
- carbon monoxide (CO), 5, 116, 147, 346–48
- fusion reactions, 45
- graphite, 213–17
- isotope ratio, 213
- nuclear resonance, 46–50
- properties, 7–17
- radicals, 108, 130. See also carbon dioxide (CO₂)
- methane (CH₄)
carbonaceous chondrites (meteorites), 78, 84, 132–33, 181, 364
carbonate globules, 362–63
carbonate rocks, 88–92
carbon dioxide (CO₂), 12–13, 21, 73, 107, 115–16, 145–47, 203–204, 218, 228, 256, 268–71
- Earth’s carbon cycle, 89–92
- on Mars, 286–88, 295, 345–53, 356–57
- role in photosynthesis, 223–25
- structure, 15
- on Venus, 88–89
carbon-14 (¹⁴C) labeling, 345–48
Cassen, Pat, 304, 307
Cassini mission, 317–24, 367
catalysis, 115, 160–62, 166–69, 172, 251
Cech, Thomas, 159–60, 183–84, 188
Ceres, 75–76
ceviche, 254–55
chalcopyrite (CuFeS₂), 251
champagne, 203
chaperones, 248–49
Charbonneau, David, 328
Charon, 30, 96
Chelyabinsk, 63
CHEOPS mission, 336
chert, 217–19, 227
chirality, 171–76, 206–7
Chivian, Dylan, 271–72
Chlorobiaceae, 223
Chloroflexaceae, 223
chlorophyll, 224–25
chloroplasts, 237
cholesterol, 149, 237
chondritic meteorites, 78, 84, 132–33, 181, 364
chromosomes, 199, 231, 239
67P/Churyumov-Gerasimenko (comet), 131–32, 303
Chyba, Chris, 310
circularly polarized light, 174
citric acid cycle, 146, 203, 228–29
- discovery, 228
Civis, Svatopluk, 119–20
clay minerals, 154–57
climatic fluctuations, 95
closed universe, 35–40
Cloud, Preston, 244
clouds (as habitats), 279, 341
coacervates, 144
codons, 191–96
cold adaptation, 255–60
cold shock proteins, 248
Collins, Michael, 276–77
comets, 63–66, 131–35
complex organisms: probability, 244
condensation processes: aldol condensation, 115
- planet formation, 69–80, 83
- purine nucleobases, 118
Conrad, Pete, 277
continental drift, 246
continuously habitable zone, 91, 336
convergent evolution, 232
Copernican principle, 49–50
Copernicus, Nicolaus, 27, 49–50
copper (Cu), 230, 251
Corliss, John B. “Jack,” 246–47
coronaviruses, 101, 159
Cosmic Background Explorer (COBE) satellite, 40
COSMIC-LOPER, 181–82
cosmic microwave background (CMB), 29–32, 36
cosmic rays, 106, 131, 292, 361
COVID-19, 101
Crick, Francis, 51, 158, 178–79, 208
critical density (of the Universe), 36–37
crystallin, 248
crystallization, 4, 79, 216, 256
CspB, 248
Curiosity (Mars rover), 291–95, 356–58
cyanimide, 124–26
cyanoacetaldehyde, 120
cyanoacetylene, 120–21, 126
cyanobacteria: early fossils, 218–21
- in extreme environments, 262
- inventing photosynthesis, 222–26
- lichen-forming, 238
- stromatolites, 219–21
cyanonitrile, 110, 124
cytosine, 198

Daniel, Isabelle, 273
dark energy, 37
dark matter, 37
dark reaction (of photosynthesis), 225
Darwin, Charles, 141–42, 241
dating methods, 79
Dawn mission, 76
Dead Sea, 263–64
Deamer, David, 133–34, 149–51, 188–89
Deep Carbon Observatory, 272–73
deep sea: pressure, 266–68
- temperature, 252. See hydrothermal vents
DegP (heat shock protein), 248
dehydration reactions, 121–22, 127–28
Deinococcus radiodurans, 260–61
density of the Universe, 34–37
deoxyribonucleic acid. See DNA (deoxyribonucleic acid)
deoxyribose, 101, 121–22, 196
desert, 237, 260–63, 344, 352
Desulforudis audaxviator, 272
deuterium (²H), 32–35, 44, 46, 89, 282, 295
deuterostomes, 241
diacylglyceride, 205–6
diaminomaleonitrile, 118
Dicke, Bob, 26–28
dihydroxyacetone, 115
dinosaurs, 198, 215
Dione: orbital resonance, 323
- properties, 314, 322
- tectonic activity, 322
Discovery missions, 355
diving, 266–68
division of labor, 205
DNA (deoxyribonucleic acid): advantages, 196–97
- ancient, 197
- basics, 101
- before or after proteins, 198–99
- chirality, 172
- circular, 239
- difference from RNA, 196–97
- genetic code, 192–94
- histones, 231–32
- linear chromosomes, 239
- origins, 196–99
- polymerase, 164, 202, 250
- repair, 260–61
- stability, 197
DnaJ, 248
DnaK, 248
domains of life, 209–11, 243
Doppler, Christian, 27
Doppler shifts, 27, 36–37, 327–30, 334
Drake, Frank, 371–74, 377
Drake equation, 373–74
Driessen, Arnold, 207
drought, 260–64

Earth: abundance of elements, 8–9
- center of the Universe, 49
- energy balance, 221–22
- engulfed by Sun, 45
- geological timeline (table), 214–15
- history of life, 209–43
- location within Milky Way, 59
- magnetic field, 365
- origins, 69–86
- primeval conditions, 97–107
- search for life, 339–40, 378
- tides, 57–58
Echo (communications satellite), 25
ecological niche, 228, 241
ecosystems: origins, 219–21
Edmond, John, 246–47
Einstein, Albert, 49
Einstein equation (E = mc²), 30
electric discharge, 106–8
electron, 32, 43, 46, 79. See also radical reactions
elements: formation processes, 32–35, 43–48
- life-forming elements, 6–17
- nuclear binding energy, 35
- relative abundances, 8–9
enantiomers, 172–75
Enceladus, 322–24, 367
- geysers, 322–23
- orbital resonance, 323
- reflective surface, 322
- temperature, 323
endolithic organisms, 258, 263, 268–74
energy (needed for life), 20–22. See also metabolism
entropy, 21
enzyme: DNA polymerase, 164, 202, 250
- DNA repair, 198–99, 260–61
- efficiency, 181, 185
- metabolic, 199–204
- origins, 199–204
- tRNA synthetase, 179
equilibrium condensation model, 71–80
equilibrium/disequilibrium, 21, 41, 44, 247
Eris, 78
erosion, 85, 212, 216, 289, 297, 339
Eschenmoser, Albert, 126, 175–76
Escherichia coli, 160, 207, 248–49
Eukaryotes (eukarya): definition, 209
- origins, 231–38
- structure of cell, 231–33
Europa, 302–14
- density, 307
- discovery, 302
- habitability, 310
- ice rafts, 309
- life, 367
- magnetic field, 307–8
- ocean, 307–14, 367
- orbital resonance, 304–5
- properties, 305
- smooth surface, 307–11
- tidal energy, 305, 307, 310
evolution, 4, 209–43
- convergent, 232
exceptionalism, 49
exoplanets. See extrasolar planets
extinctions, 215
extrasolar planets, 326–37
- atmospheres, 368–70
- direct imaging, 330
- first discovery, 327
- habitability, 335–36
- life, 368–70
- methane, 368–69
- transit observation, 327–30, 368
extraterrestrial life (search for), 339–79
- on Mars, 343–58
- in Martian meteorites, 358–67
- on Venus, 342–43
extreme conditions, 246–75
- Mars, 343–58
- Venus, 342–43
extremophiles, 246–75
- commercial use, 207
- Mars, 286
eyes, 222

galactic habitable zone (GHZ), 59–60
galaxy formation, 41–56
Gale Crater (Mars), 291–95
Galilean satellites, 302–14
- table of, 305. See also Callisto
- Europa
- Ganymede
- Io
Galilei, Galileo, 302, 314
Galileo mission, 65, 302–303, 307–12
Gamow, George, 26–28, 46, 61–62
Ganymede, 304–5, 311–12
- discovery, 302
- magnetic field, 311
- ocean, 311–12
- orbital resonance, 304–5
- properties, 311–12
- topography, 311–12
gas chromatography and mass spectrometry, 344, 352–54
gas giants: extrasolar, 331–36, 368
- moons, 302–14, 367
- origins, 71–72, 74–77. See also Jupiter
- Saturn
GCMS, 344, 352–54
gel electrophoresis, 210
gene expression, control, 232, 248
genes-first theories, 153–58
genetic code: codon assignment (table), 192
- evolution, 191–96
- exceptions, 191
- frozen accident, 191–92
- robustness, 192–93
genome: archaeal, 211
- bacterial, 200–203
- minimal, 200–201
- mitochondrial, 191
- organized in chromosomes, 239
- RNA vs. DNA, 196–98
genomics, 200–201, 233–36
Geogemma barossii, 254
geological processes, 90–91, 357. See also plate tectonics
- volcanism
geological timescale (table), 214
geysers, 323–24
Ghadiri, Reza, 157–58
Gilbert, Walter, 162–63
Gladman, Brett, 360
Gliese 581 (star), 328
Gloeomargarita lithophora, 237
glucose, 112–13, 200, 203, 226, 229
glutamic acid (glutamate), 189
glyceraldehyde, 115, 225
glycerol, 205–7, 256
glycine, 106, 112, 131–33, 192–94, 346
glycolic acid, 106
glycolysis, 203
gold (Au): mining, 251
Gold, Thomas, 270
Golden, D. C., 365
Gould, Stephen Jay, 240
graphite, 213
gravitational forces: dark matter, 37
- early Universe, 39–42
- Jupiter, 304, 321
- measurements, 312–13
- Moon, 80–81
- planet formation, 70
- inside stars, 44–48
- the Sun, 48, 57–58, 66, 143
gravitational waves, 54–55
greenhouse effect, 89, 279
GroEL/GroES, 248
guanine, 101, 117, 119–20
guanosine, 137, 210
guanosine triphosphate (GTP), 165
Guth, Alan, 31

habitability, 91, 270, 310, 333
- Europa, 310–11
- extrasolar planets, 332–36
- Mars, 279–301
- Titan, 321
habitable worlds, 276–338
Hadean eon, 212
Haemophilus influenzae, 201
Hafnium (Hf), 82
Haldane, J. B. S., 98, 144, 381
Haloarcula marismortui, 186
Halobacterium, 222–23
halophiles, 222–23, 263–64
halotolerance, 263–64
handedness, 171–76, 206–7
Hawking, Stephen, 377
heat adaptation, 249–55
heat shock, 248–49
heavy elements, 43–56
Heimdallarchaeota, 236
helium (He), 6, 32–35, 41, 71, 76–78, 94, 135, 331,
Helmholtz, Hermann von, 142
hematite, 290
hemoglobin, 162, 189
hexose. See sugars
histidine, 111, 192
Hodges, Elizabeth Ann, 63
homochirality, 172–76
Hooker, Joseph, 141–42
Horikoshi, Koki, 254
horizontal gene transfer, 192–3
Horning, David, 165–66
Horowitz, Norman, 346
Hoyle, Fred, 22, 28, 46–50, 144
Hsp31/Hsp90/Hsp104, 248
Hubble, Edwin, 27–28
Hubble Space Telescope, vii, 43, 65, 310, 355, 369
Huber, Claudia, 147
Hud, Nick, 126
Huygens (Titan lander), 317–20
Huygens, Christiaan, 314–15
hydrogen (H): abundance in Universe, 32–35
- chemical life systems, 6
- fusion reactions, 41–56
- hydrogen bonds, 19, 182, 197
- hydrogen to deuterium ratios, 89, 94
- isotopes, 32
- Jupiter, 71–72
- loss from atmosphere, 89–94
- nuclear binding energies, 32–35
- primordial planetary conditions, 97–99
- properties, 6
- radical, 5
- volatile inventory, 83–94
hydrogen cyanide (HCN), 108–10, 117–20
hydrogen fluoride (HF), 18, 20
hydrogen sulfide (H₂S), 111, 130, 138, 145–47
hydrolysis, 110, 121, 197–98
hydrophobic effect, 19–20
hydrothermal vents, 145, 252–53
- discovery, 252
- ecology, 252–53
- structure, 253
Hyperion: properties, 314
hypoxanthine, 122–24,

LACROSS mission, 96
Lagrange point, 369
Lake, James, 234–35
lakes: under-ice, 258–60
Lake Vostok, 258–59, 274
Lake Whillans, 259–60
Lancet, Doron, 149–51
laser altimeter, 292
Laser Interferometer Gravitational-Wave Observatory, 55
Laskar, Jacques, 95–96
last universal common ancestor. See LUCA
late heavy bombardment, 85, 212
lead (Pb), 79, 88
leucine, 112, 189, 192–94
Levin, Gilbert, 345, 353
Levy, David, 63–65
lichen, 143, 257
life: anthropic principle, 49–50
- definition, 2–6
- detection, 339–42
- formation requirements, 6–17
- galactic location, 59–60
- history, 209–45
- Jupiter, 22
- limits, 246–75
- Mars, 280–81
- multicellular
- origins, 140–77
- primordial planetary conditions, 140–42
- probabilities, 244
- ring of, 234–35
- search for, 339–79
- timeline (table), 214–15
- tree of, 234–35. See also intelligent life
life-forming elements, 6–17
light harvesting, 222
lightning, 98–99, 106–7, 113, 319, 371
light reaction (of photosynthesis), 225–26
LIGO, 55
limestone, 88–89, 221, 288
Linde, 31
Lindquist, Susan, 248
lipids, 129–31, 149–51, 168–69, 205, 207, 257
lipid world, 149–51
lithium (Li), 33–35
Lohse, Peter, 184
Lokiarchaeota, 235–36
Lowell, Percival, 280–84
LUCA, 180–83, 210–11
- dating, 230
- genes, 167
- genetic code, 195
- linked to thermophiles, 255
- membranes, 205
- metabolism, 201–4
Lunar Prospector, 94–96

Magallón, Susana, 242
magnesium (Mg), 16, 52, 89, 123, 128, 137, 154–55, 160, 169, 291, 293
magnetite, 363–65
magnetotactic bacteria, 363, 365
male (uselessness of), 239
mammals, 215, 240, 268
Mariana Trench, 90, 105
Mariner missions, 72–73, 284–88
Maritan, Amos, 182
Marois, Christian, 330
Mars: “canals,” 280–84
- cattle population, 356
- color changes, 280–84
- density, 72, 74
- dust storms, 284, 286
- exploration, 278–301
- geology, 285–300
- groundwater, 297–300
- gullies, 297–99
- habitability, 278–301
- life, 343–58
- meteorites, 358–67
- methane, 356–57
- moons Phobos and Deimos, 95
- origins, 74–76
- permafrost, 295–96
- pole caps, 280, 282, 295
- sample-return mission, 301
- seismic activity, 297
- subsurface habitats, 297–300
- temperature, 286–87
- topography, 285–86
- watery past, 286–95. See also Curiosity (Mars rover)
- Opportunity (Mars rover)
- Perseverance (Mars rover)
- Phoenix (Mars lander)
- Spirit (Mars rover)
- Viking missions
Mars Express (orbiter), 296–97, 299–300, 355–57
Mars Global Surveyor, 297–98, 355
Mars missions (Mars 2, Mars 3, ...), 343–44
Mars Observer (orbiter), 355
Mars Odyssey (orbiter), 288, 295, 355
Mars Pathfinder (lander), 355
Mars Reconnaissance (orbiter), 288–89, 299
Mars Science Laboratory (Curiosity), 291–95, 356–58
Martel, Jan, 364
Martin, William, 147–48, 203
mass transport, 22
Mather, John, 40
Maus, Deborah, 357
MAVEN (spacecraft), 288
Maxwell equations, 174
Mayor, Michel, 327
McKay, Chris, 262, 354
McKay, David, 360–61, 365–67
McKinley, James, 271
McSween, Harry, 364
mechanical life systems, 3–4
meiosis, 239
membrane, 205–7
mercury (Hg), 164
Mercury (planet), 72–73, 86–87, 278
Meridiani Planum, 289–91
mesophiles, 248
MESSENGER (spacecraft), 73, 86
messenger RNA. See mRNA
metabolism: network, 199–204
- origins, 184–85
metabolism-first theories, 145–53
metagenomics, 236, 273
metals (astronomical definition), 44
meteorites, 63, 84, 358–67
- ALH84001, 360–67
- Antarctica, 361–62, 366–67
- Martian, 358–67
- Murchison, 133, 358
- Nakhla, 359, 365–67
- SNC, 358–59
- Tissint, 359
- transit Mars to Earth, 361
methane (CH₄): amino acids, 98–102
- compared to silane, 12–13
- disequilibrium, 339–40
- extrasolar planets, 368–69
- extraterrestrial sources, 131
- greenhouse gas, 13
- Mars, 356–57
- primordial planetary conditions, 98–120
- produced by microbes, 210, 271
- properties, 12–13
- radical reactions, 108–9
- Titan, 315–21
- volatile inventory, 98–102
Methanococcus jannaschii, 233
methanogens, 210–11
Methanopyrus kandleri, 210
methylglycine, 133
methyl radicals, 5, 108–9
micelles, 149, 151
microfossils, 214, 217–21, 237, 363
Miller, Stanley, 97–112, 134, 138
Miller-Urey chemistry, 97–138
Milky Way, 27, 37, 54, 56, 59–60, 373–74, 377
Milner, Yuri, 377
Mimas, properties, 314
mirror images. See chirality
mitochondrion, 228–29
Mojzsis, Stephen, 213–15
molecular chaperones, 248–49
monomers: amino acids, 100
- chirality, 172–75
- DNA, 101
- nucleobase synthesis, 117–27
- phosphorimidazolides, 157
- polymerization processes, 135–38
- prebiotic syntheses, 106–27, 147
- RNA, 136–37, 158, 167–71
montmorillonite, 136, 154–55
Moon, 80–82, 86–87, 262, 276–78
Moorbath, Stephen, 216
Moore, Peter, 186–87
Morabito, Linda, 305–6
Mossbauer spectrometer, 291
Mount Sharp (Mars), 295, 358
mRNA, 190
- editing, 231–32
- genetic code, 191–96, 198
Mullis, Kary, 251
multicellular organisms, 228, 244, 252
Murchison meteorite, 133, 358
mutation, 193
Mycoplasma genitalium, 201

NADH, 185, 229
NADPH, 225
Nakamura, Tomoki, 134
nanobacteria, 364
nanofossils, 361, 364
Neptune, 77–78, 324
- moons, 324
neutrinos, 37
neutrons, 30, 32–37, 52–55
neutron spectrometer, 86, 284, 292, 295, 355
neutron star, 53–55
New Horizons mission, 324–26
Newton, Isaac, 49
nickel (Ni), 16, 73, 105, 145, 147
Nielson, Peter, 176
nitrogen (N): bond strength, 8–10
- compounds, 65, 69, 103
- electronegativity, 103–4, 181
- nitrate, 272
- nucleobase, 197
- peptide bond, 102
nitrogen (N₂): Earth’s atmosphere, 282
- fixation, 204, 238, 251
- liquid, 11, 256–57
- Miller-Urey experiment, 107
- Pluto, 326
- Titan, 315, 319
- Triton, 324
- Venus, 88
nitrogenase, 204, 230
N-methylalanine, 86, 109
North Pole, Australia, 217–19
Nostoc commune, 257
nova, 52
nuclear binding energies, 33, 53
nuclear resonance, 47, 49–50
nucleic acids, 101, 117–29. See also DNA (deoxyribonucleic acid)
- RNA (ribonucleic acid)
nucleobase synthesis, prebiotic, 117–29
nucleons, 30–34, 40–41
nucleosides, 121–29,
nucleosynthesis, 32–41
nucleotides, 121–29, 135–36, 160–66, 170
- chirality, 173
- as cofactors, 184–85
- genetic code, 191–96. See also ADP
- ATP
- FADH₂
- NADH
- NADPH
- ribonucleotide reductase
nucleus (cell), 231–33, 237, 239
Nuvvuagittuq, 217

octopus eyes, 222
Oort Cloud, 72, 84
Oparin, Aleksandr, 98, 144, 149
open universe, 36–37
Opportunity (Mars rover), 289–91, 355
orbital (molecular), 11–14
orbital resonance. See resonance
order (phylogenetic group), 240
ordered/disordered states, 21
Ordovician, 240
organelles, 232
Orgel, Leslie, 118, 122–24, 129, 137, 157–58, 178–79
origin of life, 140–177
Orion nebula, 67
Oro, John “Juan,” 117–18,
Oumuamua, 84
outer Solar System: habitable worlds, 302–26
- life, 367
oxaloacetate, 228
oxic atmospheres, 104, 204, 226–27
oxidation, 21, 138, 185, 223–24, 244, 251, 345
oxidation state, 223
oxidative phosphorylation, 229
oxygen (O): abundance, 8, 20
- bond strength, 8–10
- carbohydrates, 112–13
- clay, 155
- compounds, 129
- double bonds, 15
- electronegativity, 104–5
- fire, 4–5
- fusion, 50–53
- hydrogen bonds, 182
- isotope ratio, 81, 359, 363–64
- missing from DNA, 101, 196–97
- phosphate groups, 127
- photolysis of water, 91–93
- radical reactions, 5, 116, 261
oxygen (O₂): atmosphere, 21, 214–15, 237
- diving, 266
- Europa, 310
- first environmental catastrophe, 226–27
- inhibiting nitrogenase, 204, 230
- produced by photosynthesis, 105, 224–27, 244
- required by chemosynthetic organisms, 269
- sign of life, 293, 339–40, 350–53
- volatile inventory, 65, 103. See also aerobic metabolism
- ozone layer
Oyama, Vance, 349
ozone layer, 242

Pacific Ocean, 81, 246, 276
palimpsest, 201–2
Palmer, Patrick, 372
panspermia hypothesis, 142–44, 179, 361
Papineau, Dominic, 217
Pasteur, Louis, 140–41, 171, 176
Pauli, Wolfgang, 37
Pauling, Linus, 182
PCR, 251–52
Peale, Stan, 304, 307
Peebles, Jim, 26–28, 61–62, 327
51 Pegasi (star), 327, 377
pentose. See sugars
Penzias, Arno, 25–29, 61–62
peptides, 157–58, 188–90
peptidyltransferase, 184, 187
perchlorate, 353–54
periodic table, 7–8, 11–12, 16–17
Perseverance (Mars rover), 300–301
Phanerozoic eon, 215
phenylalanine, 111, 192–93
Phoenix (Mars lander), 295–96, 353–54
phosphates, 101, 121–29, 197, 343
phosphine, 342–43
phospholipids, 149
phosphorimidazolides, 129, 135
photolysis (of water), 227, 244, 279, 340, 342
photons, 21, 28–30, 32, 38–39, 142, 226, 330, 368
photosynthesis: Calvin cycle, 225
- chloroplasts, 232, 237, 239
- dark reaction, 225, 373
- indepencence from, 269–70, 274
- light reaction, 225
- origins, 221–26
- photosystems I and II, 224–26
photosystems I and II, 224–26
pH scale, 265
pH values, 254, 266
phylogeny, 209–11
pi bond, 12
pigeon droppings, 25–26
Pioneer missions, 302–3
Pioneer Venus mission, 89
Planck (spacecraft), 36, 40
planetesimals, 70–71
planet formation, 69–80
plate tectonics, 89–92, 105, 212, 246
PLATO mission, 336
Pluto, 78, 324–26
polyalcohols. See sugars
polycyclic aromatic hydrocarbons, 362–63
polycytidine, 137
polymerase chain reaction, 251–52
polymerization processes, 102, 116, 119, 137, 147, 157–58, 162–65, 167–71, 175–76
polymers, 127–28, 135–37, 156–57, 162–76, 181–82, 188–90, 197–99
polyols. See sugars
polypeptides, 181–82, 188–90
- origins, 188–90
population I stars, 41, 55
population II stars, 41, 55–56
population III stars, 41–43, 56
porphyrins, 189
positrons, 32
potassium (K), 74
Prasiola crispa, 257
prebiotic synthesis, 97–139
predators, 241
pre-solar nebula, 8, 66, 78–79, 174
pressure, 266–68
primordial planetary conditions, 82–94, 97–139
Project Ozma, 371–72
proline, 112, 133, 192
Prometheoarchaeum, 236
propionic acid, 106
protease, 159, 172
protein biosynthesis, 178–79, 189
proteins: basics, 101–2
- before or after DNA, 198–99
- catalysts, 151, 182, 199–204
- chirality, 172
- folding, 172, 181–82, 248
- histones, 231, 233, 239
- iron-sulfur clusters, 148
- membrane pores, 222–23
- metabolic enzymes, 199–204
- origins, 181–82, 188–90, 198–204
- ribosomal, 186–87
- stability, 255
- stress proteins, 248–49
- structures, 209, 264
Proterozoic eon, 214, 221
protogalaxies, 42
protons, 30–39, 44, 53–54
protoplanets, 69–80
protostomes, 241
proto-Sun, 66–69
psychrophiles, 256–60
Ptolemaic system, 302
purine nucleobases, 117–29
purple membrane, 222–23
pyrimidine nucleobases, 117–29
pyrite (FeS₂), 146, 227, 251
Pyrolobus fumarii, 254
pyruvate, 200, 203, 229

radical reactions, 4, 107–8, 129, 145
radio-frequency radiation (radio waves), 25, 29, 299, 370–71, 374–75
radioisotopic dating, 78–79, 216
radiolysis, 272, 310
Ramakrishnan, Venkatraman, 186–87
Rasmussen, Birger, 219
recombination event, 38–39
red dwarf stars, 57–58, 328, 332
red giants, 45, 48
Redi, Francesco, 140
red shift, 26–29, 38, 42
reducing environments, 104–31
reduction (chemistry), 131, 145–47, 185, 225, 229, 268–69, 343
Rees, Martin, 50
refractory materials, 69–74, 94
re-ionization process, 43
reproduction: definition of life, 2–6
- sexual v. asexual, 239
resonance: carbon nucleus, 47–50
- Enceladus-Dione, 323–24
- Io-Europa, 304–6
- Mercury-Sun, 58
- Moon-Earth, 57
- planetesimals–outer planets, 83
reverse transcriptase, 164
Reynolds, Ray, 304, 307
Rhea, 322
Rhizocarpon geographicum, 143
Rhodopseudomonas viridis, 223
ribonucleic acid. See RNA (ribonucleic acid)
ribonucleotide reductase, 199
ribonucleotides, 185
- chirality, 173
- cofactor, 184–85
- 2′ hydroxyl group, 196–97. See also ADP
- ATP
- FADH₂
- NADH
- NADPH
ribose, 101, 112, 116–17, 122–28, 134, 172–75, 196–97
ribosomes, 179, 183–88, 190
- reconstitution, 186–87
- ribozyme, 160–61
- 16S RNA, 210–11
- structure, 186–87
ribozymes, 159–71, 183–88
- hammerhead, 165, 185
- ribosome, 160–61
Ricketsiales, 235
Rivera, Maria, 234–35
RNA (ribonucleic acid): autocatalytic hydrolysis, 196–97
- basics, 101–2
- catalysts, 159–71, 183–88
- genetic material, 196
- origins, 135–37
- primer, 164, 198
- ribosomal, 210–11
RNA polymerase, 164
RNA world, 158–71, 179, 183–88
robots, 3–4
rocks: half-life, 212
Rosalind Franklin (Mars rover project), 301
Rosetta mission, 131–32
Rubidium (Rb), 79
Rubin, Vera, 37
Russell, Michael, 147–48

Sagan, Carl, 91, 143, 211, 315, 320–21, 370–71, 373–75, 378
- Contact, 370–71
salinity, 260–64
Saturn, 76–77, 314–24
- missions overview, 303–4
- moons, 314–24
scattered disk, 78
Schiaparelli, Giovanni, 280
Schidlowski, Manfred, 213
Schleper, Christa, 135
Schopf, William, 217–18
Schrödinger, Erwin, 1–2, 23
Schulze-Makuch, Dirk, 357
Scott, Edward, 364
sea water (salt content), 253, 256
self-replication, 3–7, 137, 145, 152–58, 162–71
sequence, complementary, 137, 157, 164
- gene, 101
- genome, 198, 233
- protein, 102
- random, 162–63
- ribozymes, 158–71
- template, 137, 157, 162
SERENDIP, 372, 376
serendipity, 372
serine, 112, 191–93
SETI, 370–78
- at home, 376
- institute, 375
- NASA program, 372, 375
sex, 239
Shoemaker, Carolyn, 63–65
Shoemaker, Eugene, 63–65, 94
Shoemaker-Levy 9, 63–66, 94
sigma bond, 12
silane, 7–8
silicates, 16, 69–74, 81–82, 104–5, 154–56, 216, 227, 305, 314, 369
silicon (Si), 7–16, 52–53
Sinton, William, 282
67P/Churyumov-Gerasimenko (comet), 131–32, 303
skeleton, 240–41
Slipher, Vesto, 26–28
Smoot, George, 40
snowball Earth, 92, 258–59
snow line, 75
Soai, Kenso, 175
sodium, 56
solar nebula, 81, 94, 66–80
Solar System: composition, 9
- habitable worlds, 278–326
- heliocentric model, 49
- origin and evolution, 56–58, 66–80
- radioisotopic dating, 79
solar winds, 67, 69, 77, 80, 288
solfatare fields, 253–54, 264
solvents, 17–20
Spallanzani, Lazzaro, 140
sperm whale, 268
sphingolipids, 149
Spirit (Mars rover), 289–91, 355
splicing reactions, 159–60, 163
spontaneous generation, 140–42
spores, 142–43, 179, 277
spreading centers, 89–90, 246
Stardust (spacecraft), 131
Starobinsky, Alexei, 31
stars: formation, 41–56, 66–67
- life supporting, 56–58
- multiple, 56–57
- red dwarf, 57
Steitz, Tom, 186–87
stellar winds, 67
sterilization methods, 249
sterols, 149, 237–38
Stetter, Karl-Otto, 211
Stevens, Todd, 271
Stewart, Potter, 2
Stolper, Edward, 364
stratosphere, 242
Strecker, Adolph, 109–10
Strecker synthesis, 109–10, 133
Strelley Pool, Australia, 219, 221
stress response, 248–49
stromatolite, 219–21
strontium (Sr), 79
subduction zones, 90, 105
subsurface habitats, 268–73
sugars, 112–17
- chirality, 171–72
- metabolism, 145, 201, 229
- photosynthesis, 225
- prebiotic synthesis, 112–17, 124, 130
sulfides: prebiotic chemistry, 147
- role in chemosynthesis, 252–54, 269
- role in photosynthesis, 223
sulfur-containing amino acids, 111, 138, 164
Sun, the, 44–45, 55, 66–69
super-Earths, 331–36, 368–70
supernovae, 52–54
superoxides, 353
supracrustal rocks, 213, 217
Sutherland, John, 124–26
symbiosis, 229, 238, 242, 252,
Szostak, Jack, 163, 168–69, 184

Tagish Lake, British Columbia, Canada, 84
tardigrades, 261–62
technology: limits, 370
temperature scale, 250
template-directed polymerization, 137, 153, 157–58, 162–71, 190, 202
terpenoid, 205–7
terrestrial planets, 9, 45, 71–72, 95, 98, 103–5, 331–33, 369
Tesla, Nikola, 371
TESS mission, 336
Tethys, 314
Tetrahymena, 159–60
Thermoanaerobacterium saccharolyticum, 251
thermodynamics, 1–2, 8, 21, 128
thermophiles, 249–55
thermostabilization, 255
Thermotoga elfii, 251
Thermotoga maritima, 254–55
Thermus aquaticus, 250–52
- Taq polymerase, 250–52
thiols, 131
Thiorhodaceae, 223
4-thioUTP, 164
third-order reactions, 34
tholins, 315–16
thorium (Th), 49, 94
threose, 175–76
thymine, 101, 117
- importance of methyl group, 198
tidal locking, 57–58, 333
time requirements, 23, 58
Titan, 314–24
- atmosphere, 315
- discovery, 314–15
- habitability, 321
- haze, 315–17
- life, 321, 367
- methane cycle, 316–19
- temperature, 316
- topography, 217–18
Tjhung, Katrina, 165–66
Totani, Tomonari, 170
Trace Gas Orbiter, 357
transit observation, 327–30, 334–36, 368–70
transmutation, 141
TRAPPIST-1 (planetary system), 332–34, 369
tree of life, 207, 210, 232–34
trehalose, 261
tricarboxylic acid cycle, 146, 203, 228–29
- discovery, 228
trinuclear fusion, 33
tritium (³H), 32–35
Triton, 324
tRNA, 160, 189–90, 195–96
tRNA synthetase: evolution, 195–96
troilite (FeS), 130–31, 146
tryptophan, 111, 191–92, 202
T-Tauri stars, 66–69
tungsten (W), 82
tun state, 261
tyrosine, 111, 192, 202

Wächtershäuser, Günter, 145–48
water (H₂O): boiling point, 10
- carbon dioxide (CO₂) regulation, 89
- Ceres, 76
- in clay, 154–55
- Enceladus, 322–23
- Europa, 308–11, 367
- extrasolar planets, 333, 368–69
- extraterrestrial sources, 83–86
- heat capacity, 18
- Jupiter, 74–75
- Jupiter’s moons, 302–14
- Mars, 279–99, 355
- Moon, 96
- photosynthesis, 222–26
- planet formation, 71–76
- Pluto, 324–25
- primordial planetary conditions, 97–102
- properties, 17–20
- radical reactions, 108, 115–16
- required for life, 17–20
- Saturn’s moons, 314–24
- snow line, 69–75
- as solvent, 17–20
- Titan, 314–21
- Venus, 88–89
- volatile inventory, 66, 83–94, 102–4
weak nuclear forces, 173
weathering processes, 89, 293
Wegener, Alfred, 246
Wells, H. G., 281
Whaling, Ward, 47
White, Harold, 184–85
white dwarf stars, 50
Wilkinson, David, 26–28, 40
Wilkinson Microwave Anisotropy Probe (WMAP), 40–41
Wilson, Robert, 25–29, 61–62
Wisdom, Jack, 95–96
Wittung, Pernilla, 176
Woese, Carl, 158, 209–11, 232–33
Wood-Ljungdahl pathway, 203–4