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What it means to be an astrobiologist

Laurie Barge Caltech Postdoctoral Scholar Jet Propulsion Laboratory / NASA Astrobiology Institute (Icy Worlds). What it means to be an astrobiologist. Astrobiology: fundamental questions. How does life begin and evolve? Does life exist elsewhere in the universe?

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What it means to be an astrobiologist

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  1. Laurie Barge Caltech Postdoctoral Scholar Jet Propulsion Laboratory / NASA Astrobiology Institute (Icy Worlds) What it means to be an astrobiologist

  2. Astrobiology: fundamental questions • How does life begin and evolve? • Does life exist elsewhere in the universe? • What is the future of life on Earth and beyond?

  3. Navajo Sandstone, UT, USA • Analog for “blueberries” at MeridianiPlanum, Mars – self-organizing precipitates formed in an aqueous environment Utah Mars

  4. Chan et al. 2007, Geofluids Liesegang bands form in the presence of organic impurities (Barge et al. 2010, Chem. Phys. Lett.) Barge et al. 2011, Geofluids

  5. Prebiotic Earth and Early Mars Credit: MinikRosing Credit: Daniel Smith Higher geothermal gradients CO2-rich atmosphere No atmospheric O2 No land Oceans contained dissolved metals (Fe, Ni)

  6. Emergence of life at alkaline hydrothermal vents Kelley, D. S. et al; Nature412, 145-149 (12 July 2001) Russell and Hall 2006; GSA Memoir 198, 1-32.

  7. Emergence of life at alkaline hydrothermal vents

  8. Emergence of life at alkaline hydrothermal vents

  9. Emergence of life at alkaline hydrothermal vents Hadean ocean: CO2, Fe+2, PO43- pH ~ 5 Hydrothermal fluid: HS-, H2, pH ~ 11 pH gradient Photo credit: Kirt Robinson, Shawn McGlynn

  10. Hydrothermal vents offer natural energy sources for emerging life • pH gradient • Ion gradients • Thermal gradients • Electrical potential • Catalytic minerals to drive organic chemistry Potential of membrane formed with Fe(II) and sulfide

  11. Laboratory studies of emerging metabolism at hydrothermal vents • Electrochemical measurements of iron sulfide membranes • (Generation of membrane potential as the hydrothermal mound forms – an energy source for proto-metabolism) Credit: IvriaDoloboff

  12. Laboratory studies of emerging metabolism at hydrothermal vents • Simulating formation of pyrophosphate (PPi), a necessary prebiotic energy storage molecule (similar to ATP) Milner-White and Russell 2010, J. Cosmol.,10, 3217-3229. 31P NMR spectroscopy Iron sulfide stabilizes pyrophosphate in hydrothermal systems Pyrophosphate forms in membrane experiments

  13. International Summer School, Santander, Spain “Origins: From the Big Bang to Life” NASA Academy Astrobiology Graduate Conference, Seattle U of Hawaii Astrobiology Winter School: “Water on Earth and in Space” Winter School, U of Arizona: “Habitable Planets: Common or Rare?” Petrophysics Internship, Marathon Oil Company Astrobiology Graduate Conference, Tällberg, Sweden NASA/Nordic Astrobiology Summer school, Iceland São Paulo Advanced School of Astrobiology

  14. What does it mean to be an astrobiologist? • Work between disciplines to answer fundamental questions • How does life begin and evolve? • Does life exist elsewhere? • What is the future of life?

  15. What does it mean to be an astrobiologist? • Work between disciplines to answer fundamental questions • How does life begin and evolve? • Does life exist elsewhere? • What is the future of life? • Collaboration - combine skills with other scientists to approach astrobiology questions in new ways • Creativity – try new things, learn new skills and generate new research ideas

  16. Acknowledgements • Isik Kanik • Michael Russell • Ivria Doloboff • Laura Zwicker • Lauren White • Richard Kidd • David VanderVelde / Caltech Liquid NMR Facility • JPL Education Office (SIRI, JVSRP, USRP Intern programs)

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