Life in the Universe: The Science of Astrobiology Carl B. Pilcher - - PowerPoint PPT Presentation

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Life in the Universe: The Science of Astrobiology Carl B. Pilcher - - PowerPoint PPT Presentation

May 26, 2023 44 likes •437 views

Solar System Ambassadors+ August 22, 2016 Life in the Universe: The Science of Astrobiology Carl B. Pilcher Former Director, NASA Astrobiology Institute NASA Ames Research Center Moffett Field, CA 1 What is Astrobiology? Study of the

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Life in the Universe: The Science of Astrobiology

Carl B. Pilcher

Former Director, NASA Astrobiology Institute NASA Ames Research Center Moffett Field, CA Solar System Ambassadors+ August 22, 2016

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What is Astrobiology? Study of the potential

  • f the Universe to

harbor life beyond Earth

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This has been pondered by philosophers...

“There are infinite worlds both like and unlike this world of ours...We must believe that in all worlds there are living creatures and plants and other things we see in this world.”

Epicurus (c. 300 B.C.)

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  • St. Thomas Aquinas (13th Cent.)

“When it is said…that many worlds are better than

  • ne, … this sort of better…does not belong to the

intention of God…because for the same reason it could be said that if he made two, it would be better that there were three; and thus ad infinitum.”

…and theologians

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Today astrobiology addresses three fundamental scientific questions

  • What is the future of life
  • n Earth and beyond?
  • How does life

begin and evolve?

  • Does life exist

elsewhere in the universe?

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Five Interconnected Areas of Science

  • 1. Diversity of life on modern Earth
  • 2. The co-evolution of life and our planet
  • 3. Diversity of Solar System environments
  • 4. Planetary environments around other stars
  • 5. The origin of life
  • a. Where and how the raw ingredients for life are

made

  • b. How a world may transform from non-living to

living

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  • 1. The Diversity of Life on Earth
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  • 1. The Diversity of Life on Earth

You are here

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Most Energy (chocolate!) Least Energy (celery!) Worst Oxidant Best Oxidant

Metabolic Diversity

Reductants

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  • 2. Co-evolution of life and the Earth

Stromatolites: Ancient and modern

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Cyanobacteria

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History of Oxygen

Time before Present (billion yrs) PO2(atm)

1 0.1 0.01 0.001 0.0001 0.00001 4.5 4 3.5 3 2.5 2 1.5 1 0.5

Multi-cellular Life

  • Prokaryotic

Life

  • First
  • Eukaryotic
  • Life
  • “Modern” O2

levels

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Europa Lakes on Titan Mars

  • 3. The Diversity of

Solar System Environments

Jets on Enceladus

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Mars – Juventae Chasma

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Enormous dry river systems indicate that large volumes of water flowed across Mars billions of years ago

Mangala Valles region ESA/DLR/FU Berlin (G. Neukum)

50 km

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Opportunity Rover Lands on Mars (2004)

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“Blueberry Bowl” (enhanced color)

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Ice under Phoenix Lander

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Liquid (saline) droplets on Phoenix lander strut

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Curiosity “Selfie” (2016)

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Streambed Deposits

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  • Mt. Sharp Foothills
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Europa (moon of Jupiter)

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Europa

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Titan Titan (moon of Saturn)

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A Hidden World

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Jets of H2O (+salts, organics) on Enceladus

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  • 4. Planets Around Other Stars

Doppler Method Keck Observatory Mauna Kea, Hawai’i

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  • 4. Planets Around Other Stars

Transit Method Kepler Planet Candidates

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The Habitable Zone

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  • 5. Origin of Life

Raw materials from space?

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Could Life Have Arisen at a Hydrothermal Vent?

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Or in a tide pool?

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Slide courtesy C. McKay

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Abiotic distributions are smooth Biotic distributions are spiked

McKay 2004 PLoS Biol 2(9)1260-12623

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McKay 2004 PLoS Biol 2(9)1260-12623

alien

Abiotic distributions are smooth Biotic distributions are spiked

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Questions?

QUESTIONS?