Rare Earth: Why Complex Life is Uncommon in the UniverseSpringer Science & Business Media, 10 dec. 2003 - 338 sidor n November 12, 2002, Dr. John Chambers of the NASA Ames - search Center gave a seminar to the Astrobiology Group at the OUniversity of Washington. The audience of about 100 listened with rapt attention as Chambers described results from a computer study of how planetary systems form. The goal of his research was to answer a dec- tively simple question: How often would newly forming planetary systems produce Earth-like planets, given a star the size of our own sun? By “Ear- like” Chambers meant a rocky planet with water on its surface, orbiting within a star’s “habitable zone. ” This not-too-hot and not-too-cold inner - gion, relatively close to the star, supports the presence of liquid water on a planet surface for hundreds of million of years—the time-span probably n- essary for the evolution of life. To answer the question of just how many Earth-like planets might be spawned in such a planetary system, Chambers had spent thousands of hours running highly sophisticated modeling p- grams through arrays of powerful computers. x Preface to the Paperback Edition The results presented at the meeting were startling. The simulations showed that rocky planets orbiting at the “right” distances from the central star are easily formed, but they can end up with a wide range of water c- tent. |
Innehåll
Why Life Might Be Widespread in the Universe | 1 |
Habitable Zones of the Universe | 15 |
Building a Habitable Earth | 35 |
Lifes First Appearance on Earth | 55 |
How to Build Animals | 83 |
Snowball Earth | 113 |
The Enigma of the Cambrian Explosion | 125 |
Mass Extinctions and the Rare Earth Hypothesis | 157 |
The Surprising Importance of Plate Tectonics | 191 |
The Moon Jupiter and Life on Earth | 221 |
Testing the Rare Earth Hypotheses | 243 |
Assessing the Odds | 257 |
Messengers from the Stars | 277 |
References | 289 |
319 | |
Andra upplagor - Visa alla
Rare Earth: Why Complex Life is Uncommon in the Universe Peter D. Ward,Donald Brownlee Begränsad förhandsgranskning - 2000 |
Rare Earth: Why Complex Life is Uncommon in the Universe Peter D. Ward,Donald Brownlee Begränsad förhandsgranskning - 2007 |
Rare Earth: Why Complex Life is Uncommon in the Universe Peter D. Ward,Donald Brownlee Ingen förhandsgranskning - 2003 |
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abundance accretion acids appear archaeans asteroid Astrobiology astronomers atmosphere bacteria billion years ago biological body plans Burgess Shale Cambrian Explosion carbon dioxide cause cell changes chapter chemical collision comets complex metazoans continental continents Conway Morris crust discovery diversification diversity early Earth Earth history Earth today Earth-like planets Earth’s surface Ediacarans ejected elements energy environmental environments Eucarya eukaryotic evolution evolutionary evolved exist extremophiles formation fossil record galaxy genes giant global greenhouse habitable zone habitats heat hydrothermal vents impact Jupiter Kasting kilometers Kirschvink land large moon life’s liquid water living lunar major mantle Mars Martian mass extinction metazoans meteorites microbes molecules multicellular nebula occurred oceans orbit organisms origin outer oxygen perhaps phyla planetary systems plate tectonics produce prokaryotic proteins radiation Rare Earth Hypothesis regions rocks Science scientists Snowball Earth solar system space stars subduction telescopes terrestrial planets tion Universe volcanic