summary life in the universe 5th edition 2022 bennett 9780691241784

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summary life in the universe 5th edition 2022 bennett 9780691241784

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summary life in the universe 5th edition 2022 bennett 9780691241784 Chapter 1 - The Possibility of Life Beyond Earth What are we searching for?Not just looking for intelligent life, but anything we can find Difficult to define life; ie. What makes us think people, mushrooms, bacteria are alive as opposed to crystals, clouds, and fire?b/c life so difficult to define, presume a search on Earth-like life because it’s all we know Is it reasonable to imagine life beyond Earth?Life once speculated on Venus (because of clouds) and Mars (canals which =/= exist) Unlikely to find multicellular life, but rather simple life (tiny microbes) Potential life on planets that surround the universe of stars New technology gives for more possibility than years past The Scientific Context of the Search 1.2 How does astronomy help us understand the possibilities for aliens?Once though earth was center of universe – geocentric Now know Earth just a tiny part of the universe Physical laws in universe also apply to Earth How does planetary science help us understand the possibilities for aliens?Planetary science – study of planets, moons orbiting, other objects that may form in association with planets (asteroids/comets); sets the context for search for life in 2 main ways 1.Learn how planets form >> understand how common we might expect planets to be 2.Learn how planets work; ie. Why Venus so hot even though only lil closer to Sun

1995: strong evidence found for existence of extrasolar planets – planet

1 and 2 (above) help understand what to look for as we search habitable worlds – worlds containing basic necessities for life habitable =/= always mean plants/animals; could be microscopic shit planet doesn’t HAVE to harbour life, but possibility How does biology help us understand the possibilities for aliens?Physics and bio are universal, so is bio as well?Complex molecules found in meteorites means can withstand harsh conditions of space >> form readily and may be common in other worlds Early origin of life on earth makes it reasonable that life could emerge on other planets with similar conditions Understand conditions needed for life; ie. Some bacteria live in ^ temps No reason to think life is rare Places to Search 1.3 Where should we search for life in the universe?1 st = search for life on earth to learn diff places/conditions life exists then the rest of our solar system b/c looking for life somewhat earth-like, would assume they need water or something similar 3 / 4

summary life in the universe 5th edition 2022 bennett 9780691241784 ie. Mars once had flowing water so could assume life may have arisen moons are also a possibility Could aliens be searching for us?SETI (search for extraterrestrial intelligence) The New Science of Astrobiology 1.4

Astrobiology: study of universe coupled with study of

life How do we study the possibility of life beyond Earth?

NASA astrobiology institute look for the following:

1.Study conditions conductive to the origin and ongoing existence of life 2.Look for such conditions on other planets in solar system 3.Look for actual occurrence of life elsewhere Astrobio meant to connect life and places it resides

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