Author(s): , , ,
Institution(s): 1. NASA/Goddard Space Flight Center, 2. SSAI/LARC
Recent Kepler observations suggest that active G-type stars are capable of producing extremely powerful flares called superflares suggesting that the early Earth may also have been exposed to such solar superflares from the young Sun. We show that super-CME (SCME) events associated with superflares were hitting the Earth’s magnetosphere with a frequency of ~1 event per day!
What was the impact of superflares, associated SCMEs and Solar Proton Events (SEPs) on the atmospheric erosion of the young Earth and planetary habitability?
In this presentation we review the results of our 3D MHD simulations that suggest that frequent and energetic SCMEs from the early Sun continuously destroyed the sub-solar parts of early Earth's magnetosphere at heights less than 1 Earth's radius. This critical finding suggests that CME shock accelerated energetic protons are capable of breaking atmospheric molecular nitrogen, the major ingredient of the early Earth’s atmosphere, into atomic nitrogen.We use 2D GSFC atmospheric code to calcylate the rate of production of odd nitrogen in the early Earth's atmosphere. This is a major process that produces hydrogen cyanide, which is an essential molecule in prebiotic life chemistry. This raises an intriguing possibility that frequent super-CMEs could be a potential catalyst of first life forms on early Earth and Mars. Our scenario could also provide a potential answer to the “faint young Sun” paradox suggesting that the direct heating comes from the energy dissipated in collisions of protons with the Earth’s atmosphere. Our model predicts that the high isotopic ratios of 14N/15N observed in the solar wind and the Earth’s atmosphere are the result of spallation of 15N mostly occurred in the early histrory of the Solar system.