ABSTRACT

Understanding how the simple molecules present on the early Earth may have set a path for complex biological molecules, the building blocks of life, represents one of greatest unsolved questions. Another great challenge is to understand how Earth supported liquid surface water under the young sun, which was 25% fainter. I will present our new concept of how these two problems can be reconciled if we look at space weather from the young Sun at the time when life started on Earth. We propose that energetic protons accelerated in shock waves driven by frequent and powerful coronal mass ejection events penetrate into the nitrogen-rich weakly reducing atmosphere and initiate the reactive chemistry by breaking molecular nitrogen, carbon dioxide, and methane, producing nitrous oxide, the potent greenhouse gas, and hydrogen cyanide, an essential compound for life. This picture may have implications on how we search for the signatures of life in the Universe.

About the Speaker:

Dr. Vladimir Airapetian is an astrophysicist in GSFC’s Heliophysics Division, Code 671 and Research Professor at Catholic University of America. Dr. Airapetian is also a PI of the NExSS team “Mission to the Young Earth 2.0” at NASA's Astrobiology Institute. He has over 20 years of experience in theoretical astrophysics, heliophysics and astrobiology. Dr. Airapetian specializes in the MHD modeling of solar and stellar winds, extreme coronal mass ejection events from the current and early Sun and their effects on Earth’s magnetosphere and ionosphere. He is leading an interdisciplinary team of heliophysicists, astrophysicists, planetary scientists, chemists and biochemists from NASA Goddard, NASA Langley, Harvard University and Tokyo Tech to understand how extreme events from the active stars affect physics and chemistry of exoplanetary habitability. Dr. Airapetian earned a Bachelor of Science and Master of Science in Physics from the Yerevan State University, Armenia and a Ph.D. in Astrophysics from the Byurakan Astrophysical Observatory, Armenian Academy of Sciences and Atomic Energy Institute, Moscow.