Space Physics of Habitability: Systems Science Approach
Discovery of over 5500 exoplanets with Kepler mission, TESS, the Hubble Space Telescope, and JWST suggests that rocky exoplanets in the habitable zones around G, K, and M dwarfs are common in our Galaxy. These detections open a new era in the characterization of the planetary atmospheric environments, the critical step in the search for conditions suitable for life and signatures of their biospheres. Are biospheres of terrestrial-type exoplanets a common phenomenon? How can we detect a (pre)biosphere from a rocky exoplanet? Can we search for Earth twins? Critical examination of the heliophysical and physico-chemical conditions that supported the emergence of life on the early Earth and other inner planets in our Solar System is a promising way to address these fundamental questions. Understanding the conditions for habitability requires the characterization and assessment of several factors: retention of a relatively thick atmosphere, presence of basic molecular compounds, and availability of persistent external energy fluxes. The consistent characterization of space environments and their impact on exoplanetary upper atmosphere and climate requires a new system science approach to characterize habitability as the evolving physico-chemical phase of an exoplanetary system. In this talk, I suggest that while we have no consistent ideas about forms of exoplanetary life other than our own, pre-life conditions that required the formation of prebiotic chemistry are well specified under laboratory conditions. These factors could have promoted the emergence and complexification of biological systems on early Earth and possibly Mars. First, I will describe our recent observational campaigns of young solar-like analogs, and data-constrained state-of-the-art MHD and kinetic models of stellar coronae, transient events (CMEs and SEPs) and discuss the impact of solar/stellar eruptive events on atmospheric escape. Second, I will discuss how the extreme space weather in the form of flares, coronal mass ejections, and energetic particle events (like 775AD event) from the recent past of our Sun provides critical insights into the atmospheric chemistry of early Earth and terrestrial-type exoplanets and assessment of their role in the formation of biologically relevant molecules. Third, I will present the recent results of laboratory experiments that reproduce the energy fluxes of particles from the young Sun and study the expected formation of amino acids and carboxylic acids, the chemical precursors of life. I will also introduce the design of our recently approved Exoplanetary Particle Irradiation Chemistry laboratory (EPIC Lab) at NASA GSFC.
Vladimir Airapetian is Professor at American University, Washington, DC, Senior Scientist at HSD/GSFC, and Distinguished Professor at Kyoto University, Japan. He received his BSc/MSc in Theoretical Physics from Yerevan State University and PhD in Theoretical Astrophysics under Prof. Ambartsumian at Byurakan Observatory in Armenia. Since 1994, Vladimir held a post-doc position at Los Alamos National Laboratory & NSO/Sunspot, and he one year later joined NASA GSFC as ASD/HST support scientist. In 2010, he is affiliated with HSD to complement his stellar research with Sun-as-a-Star studies. Since 2015, Vladimir Airapetian is one of the founding members of Sellers Exoplanetary Environments Collaboration (SEEC) at GSFC, a member of NASA’S Steering Committee of NExSS and Prebiotic Chemistry and Early Earth Environments (PCE3) Networks. Vladimir Airapetian is currently leading and actively participating in four complex international interdisciplinary research projects. These projects aim to understand the astrophysical factors supporting the origin, evolution, distribution, and future of life in the Universe: 1) the international multi-observatory observing campaign “Evolving Magnetic Lives of Young Suns” including HST/COS, NuSTAR, TESS, NICER complemented with two radio facilities, MWA, ATCA and Anglo-Australian ground based telescope; 2) Project to develop and apply a sophisticated tool PLANET-ITTR to model atmospheric escape from rocky and giant planets funded by SEEC; 3) MHD modeling of coronae, winds, superflares and CMEs from young solar-like planet hosts and to study the impact on prebiotic chemistry and climates of rocky exoplanets funded by SEEC, NASA/Exobiology, XRP, NICER, TESS, HST and HST-XMM Newton programs; 4) Laboratory experiments of proton irradiation of gas mixtures resembling the current, early Earth, Mars, Venus and exoplanetary atmospheres at Tokyo Tech/YNU, Japan, NASA GSFC & American University (EPIC Lab at GSFC).