"The Planetary Battery for the Origins of Life: The Example of Mars"

Speaker: 
Vlada Stamenkovic, NASA Jet Propulsion Laboratory, CalTech
Date: 
Friday, February 2, 2018 - 4:00pm to 5:00pm
Location: 
E25-605

A rocky planet can act as a battery fueling the origins and the evolution of life by locally providing redox gradients that can drive simple metabolic activity. In this talk, I will use Mars as an example to show first results on two very different planetary processes that generate oxygen- and hydrogen-rich surface and subsurface aqueous environments in an evolving planet.

On one hand of the redox spectrum (reducing), I will show how novel and fast geodynamic interior evolution models can be used to compute the local production of hydrogen and methane through processes like serpentinization and radiolysis of water in the Martian lithosphere across the last 4.5 billion years. We will see that specific zones on Mars had and still have the capability to generate hydrogen fluxes likely large enough to support microbial communities — with the availability of subsurface water being the greatest uncertainty. On the other hand of the redox spectrum (oxidizing), I explore how atmosphere-brine interactions governed by climate and low-temperature surface chemistry suggest the existence of shallow oxygen-rich briny environments on Mars today and in its past. I will show that oxygen concentrations in such brines (especially in perchlorates) can be large enough to sustain aerobic metabolic activity and that the availability of such aerobic environments likely varied with obliquity cycles on timescales of thousands of years.

I will show time-dependent spatial maps of such hydrogen- and oxygen-rich oases on Mars, explain what controls their formation and temporal evolution, and discuss what our results imply for the origins of life on Mars and beyond — from a planetary and exploration-driven perspective.

About the Speaker

Vlada Stamenkovic is a postdoctoral Simons Collaboration on the Origins of Life fellow at Caltech and JPL. He is a global geophysicist and theoretical physicist who explores the fundamental principles of geophysics and the co-evolution of planets and life on Earth and beyond - from their origins to modern time. MORE


This lecture is part of IAP 2018: Origin of Life Seminar Series
12.091/ 12.S593 | Instructor: Greg Fournier

A series of hosted lectures from leaders in the Origin of Life community, focusing on various dimensions of one of the most challenging problems in the biological and planetary sciences.  Topics will include the origin of cells, metabolism, replication and proteins, as well as the geochemical conditions on the Early Earth that led to prebiotic and early biotic systems.  Enrolled students will attend 4-5 seminars during IAP, actively engage in Q & A sessions with invited speakers in a panel format, and collaborate on creating an Origins of Life online blog resource highlighting the work of invited speakers.