Eruptions from Young Solar-like Stars and Impact of Habitable Environments of Rocky Exoplanets

Vladimir Airapetian
NASA Goddard Space Flight Center and American University

Is life unique to Earth or a common phenomenon in the Solar System and the Universe? This fundamental question is one of the greatest puzzles of modern science. Earth's evident long-term habitability makes it a key data point for understanding the formation of habitable worlds in the Universe. To address this fundamental question, we need to know how the basic requirements for life as we know it such as liquid water, organic compounds and persistent external energy fluxes promoted the emergence and complexification of biological systems on early Earth and how they were impacted by planetary and solar properties. The early Solar System was a chaotic place, likely subject to frequent large impacts as well as the violently changing space weather (energetic ionizing radiation flux from the solar corona, wind and transient events) from the infant (< 100 Myr) and toddler (400-600 Myr) Sun. Understanding the conditions that allowed for the emergence of life on early Earth, and whether other inner planets in our Solar System possibly also supported habitable conditions early in their histories is a promising way to address these questions. Thus, the knowledge of the heliospheric environments surrounding the early Venus, Earth and Mars is critical for evaluation of the basic requirements for life as we know it including liquid water and organic compounds. Here, I will describe recent observations of young solar-like stars and the Sun as inputs for our 3D MHD models of the corona, the wind and transient events (flares, coronal mass ejections and solar energetic particle events) and discuss their impact on atmospheric erosion and chemistry of early Earth. I will use these constrained energy fluxes to describe our recent atmospheric chemistry models impacted by energetic particles from the young solar-like stars and formation and precipitation of biologically relevant molecules on rocky exoplanets. I will then highlight our results of laboratory experiments of proton irradiation of mildly reduced gas mixtures and their implications to the climate, prebiotic chemistry and the rise of habitability in exoplanetary systems.

A 2F Conf. room（1236） / 研究管理棟２階会議場（1236号室）、Via Zoom / Zoom 開催