Presentation on theme: "Laurie Barge Caltech Postdoctoral Scholar Jet Propulsion Laboratory / NASA Astrobiology Institute (Icy Worlds)"— Presentation transcript:
Laurie Barge Caltech Postdoctoral Scholar Jet Propulsion Laboratory / NASA Astrobiology Institute (Icy Worlds)
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?
Navajo Sandstone, UT, USA Analog for “blueberries” at Meridiani Planum, Mars – self-organizing precipitates formed in an aqueous environment Utah Mars
Chan et al. 2007, Geofluids Barge et al. 2011, Geofluids Liesegang bands form in the presence of organic impurities (Barge et al. 2010, Chem. Phys. Lett.)
Prebiotic Earth and Early Mars Credit: Daniel Smith Higher geothermal gradients CO 2 -rich atmosphere No atmospheric O 2 No land Oceans contained dissolved metals (Fe, Ni) Credit: Minik Rosing
Emergence of life at alkaline hydrothermal vents Russell and Hall 2006; GSA Memoir 198, 1-32. Kelley, D. S. et al; Nature 412, 145-149 (12 July 2001)
Emergence of life at alkaline hydrothermal vents
Photo credit: Kirt Robinson, Shawn McGlynn Hadean ocean: CO 2, Fe +2, PO 4 3- pH ~ 5 Hydrothermal fluid: HS -, H 2, pH ~ 11 pH gradient Emergence of life at alkaline hydrothermal vents
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
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: Ivria Doloboff
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. 31 P NMR spectroscopy Pyrophosphate forms in membrane experiments Iron sulfide stabilizes pyrophosphate in hydrothermal systems
NASA/Nordic Astrobiology Summer school, Iceland Astrobiology Graduate Conference, Tällberg, Sweden São Paulo Advanced School of Astrobiology Astrobiology Graduate Conference, Seattle International Summer School, Santander, Spain “Origins: From the Big Bang to Life” 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 NASA Academy
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?
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
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)