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Time-line for global planetary events

NASA’s search for life in the galaxy: Information from exoplanets and the ancient Earth.

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Time-line for global planetary events

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  1. NASA’s search for life in the galaxy: Information from exoplanets and the ancient Earth John W. Delano, Ph.D. Associate Director, New York Center for Astrobiology (NASA) Distinguished Teaching Professor Dept. of Atmospheric and Environmental Sciences The University at Albany (SUNY) jdelano@csc.albany.edu http://www.origins.rpi.edu

  2. Goal 4: Understand how past life on Earth developed and evolved by integrating evidence from both geologic and biomolecular records

  3. When did the major geochemical/geophysical reservoirs form on the Earth and Mars? Atmosphere Crust Mantle Core The major geochemical/geophysical reservoirs on Mars, Earth, and probably differentiated asteroids were formed within this time-interval (green; ~50 My). Time-line for global planetary events Chemically neutral volcanic gases released from Earth’s interior impacts? 0 Myr (106 yr) in past 4567

  4. Moonrise on the Hadean Earth

  5. S. Blair Hedges and Sudhir Kumar (2009) The Timetree of Life. Oxford University Press, 551 pp. New York. “Life on Earth arose from a single source, ~4400-4200 million years ago (Ma), and quickly achieved a prokaryotic complexity.” http://www.timetree.org

  6. Why is Earth’s phylogenetic tree of life rooted in hyperthermophilic organisms? Bold lines at base of the tree of life are … hyperthermophilic chemolithoautotrophic organisms Woese et al. (1990) Proc. National Acad. Sci. USA, 87, p. 4576-4579.

  7. Late heavy bombardment ~4400 ~3800 Time in the past (Ma) Modified after … Miller S. L. and Lazcano A. (1995) The origin of life – did it occur at high temperatures? J. Molecular Evol., 41, p. 689-692.

  8. Neptune Uranus Astronomical units (AU) Astronomical units (AU) Gomes et al. (2005) Nature, 435, p. 466-469.

  9. How diverse is life on Earth? • Green plants:>105 species • Animals:>106 species • Bacteria:>6 x 103 species • Fungus:>106 species • Viruses:>3.6 x 103

  10. Goal 1: Understand the nature and distribution of habitable environments in the Universe.

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