time-line for global planetary events
DESCRIPTION
NASA’s search for life in the galaxy: Information from exoplanets and the ancient Earth. - PowerPoint PPT PresentationTRANSCRIPT
NASA’s search for life in the galaxy: NASA’s search for life in the galaxy: Information from exoplanets and the ancient EarthInformation from exoplanets and the ancient Earth
NASA’s search for life in the galaxy: NASA’s search for life in the galaxy: Information from exoplanets and the ancient EarthInformation from exoplanets and the ancient Earth
John W. Delano, Ph.D. John W. Delano, Ph.D. Associate Director, New York Center for Astrobiology (NASA) Associate Director, New York Center for Astrobiology (NASA)
Distinguished Teaching Professor Distinguished Teaching Professor Dept. of Atmospheric and Environmental Sciences Dept. of Atmospheric and Environmental Sciences
The University at Albany (SUNY) The University at Albany (SUNY) [email protected] [email protected]
http://www.origins.rpi.eduhttp://www.origins.rpi.edu
John W. Delano, Ph.D. John W. Delano, Ph.D. Associate Director, New York Center for Astrobiology (NASA) Associate Director, New York Center for Astrobiology (NASA)
Distinguished Teaching Professor Distinguished Teaching Professor Dept. of Atmospheric and Environmental Sciences Dept. of Atmospheric and Environmental Sciences
The University at Albany (SUNY) The University at Albany (SUNY) [email protected] [email protected]
http://www.origins.rpi.eduhttp://www.origins.rpi.edu
Goal 4: Understand how past life on Earth developed and evolved by integrating evidence from both geologic and
biomolecular records
Goal 4: Understand how past life on Earth developed and evolved by integrating evidence from both geologic and
biomolecular records
Time-line for global planetary eventsTime-line for global planetary events
00 45674567Myr (106 yr) in pastMyr (106 yr) in past
When did the major geochemical/geophysical reservoirs form on the Earth and Mars?
When did the major geochemical/geophysical reservoirs form on the Earth and Mars?
Atmosphere
Crust
Mantle
Core
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).
The major geochemical/geophysical reservoirs on Mars, Earth, and
probably differentiated asteroids were formed within this time-
interval (green; ~50 My).
Chemically neutral volcanic gases released from Earth’s interior impacts?Chemically neutral volcanic gases released from Earth’s interior impacts?
Moonrise on the Hadean EarthMoonrise on the Hadean EarthMoonrise on the Hadean EarthMoonrise on the Hadean Earth
S. Blair Hedges and Sudhir Kumar (2009) The Timetree of Life. Oxford University Press, 551 pp. New York.
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.”
“Life on Earth arose from a single source, ~4400-4200 million years ago (Ma), and quickly achieved a
prokaryotic complexity.”
http://www.timetree.orghttp://www.timetree.org
Woese Woese et al.et al. (1990) Proc. National Acad. Sci. USA, 87, p. 4576-4579. (1990) Proc. National Acad. Sci. USA, 87, p. 4576-4579.Woese Woese et al.et al. (1990) Proc. National Acad. Sci. USA, 87, p. 4576-4579. (1990) Proc. National Acad. Sci. USA, 87, p. 4576-4579.
Bold lines at base of the tree Bold lines at base of the tree of life are … of life are …
hyperthermophilic hyperthermophilic chemolithoautotrophic chemolithoautotrophic
organismsorganisms
Bold lines at base of the tree Bold lines at base of the tree of life are … of life are …
hyperthermophilic hyperthermophilic chemolithoautotrophic chemolithoautotrophic
organismsorganisms
Why is Earth’s phylogenetic tree of
life rooted in hyperthermophilic
organisms?
Why is Earth’s phylogenetic tree of
life rooted in hyperthermophilic
organisms?
Modified after … Miller S. L. and Lazcano A. (1995) Modified after … Miller S. L. and Lazcano A. (1995) The origin of life – The origin of life – did it occur at high temperatures?did it occur at high temperatures? J. Molecular Evol., 41, p. 689-692. J. Molecular Evol., 41, p. 689-692.
Modified after … Miller S. L. and Lazcano A. (1995) Modified after … Miller S. L. and Lazcano A. (1995) The origin of life – The origin of life – did it occur at high temperatures?did it occur at high temperatures? J. Molecular Evol., 41, p. 689-692. J. Molecular Evol., 41, p. 689-692.
~4400 ~3800Time in the past (Ma)Time in the past (Ma)
Late heavy bombardment
Gomes et al. (2005) Nature, 435, p. 466-469.Gomes et al. (2005) Nature, 435, p. 466-469.
Ast
ron
omic
al u
nit
s (A
U)
Astronomical units (AU)
NeptuneNeptune
UranusUranus
How diverse is life on Earth?How diverse is life on Earth?How diverse is life on Earth?How diverse is life on Earth? Green plants:Green plants: >10>1055 species species
Animals:Animals: >10>1066 species species Bacteria:Bacteria: >6 x 10>6 x 1033 species species
Fungus:Fungus: >10>1066 species species Viruses:Viruses: >3.6 x 10>3.6 x 1033
Green plants:Green plants: >10>1055 species species Animals:Animals: >10>1066 species species
Bacteria:Bacteria: >6 x 10>6 x 1033 species species Fungus:Fungus: >10>1066 species species Viruses:Viruses: >3.6 x 10>3.6 x 1033
Goal 1: Understand the nature and distribution of habitable environments in the Universe.
Goal 1: Understand the nature and distribution of habitable environments in the Universe.