Cometary Impactors on the TRAPPIST-1 Planets Can Destroy All Planetary Atmospheres and Rebuild Secondary Atmospheres on Planets F, G, H
Mon. Not. R. Astron. Soc. 000, 1{28 (2002) Printed 4 July 2018 (MN LATEX style file v2.2) Cometary impactors on the TRAPPIST-1 planets can destroy all planetary atmospheres and rebuild secondary atmospheres on planets f, g, h Quentin Kral,1? Mark C. Wyatt,1 Amaury H.M.J. Triaud,1;2 Sebastian Marino, 1 Philippe Th´ebault, 3 Oliver Shorttle, 1;4 1Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK 2School of Physics & Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK 3LESIA-Observatoire de Paris, UPMC Univ. Paris 06, Univ. Paris-Diderot, France 4Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK Accepted 1928 December 15. Received 1928 December 14; in original form 1928 October 11 ABSTRACT The TRAPPIST-1 system is unique in that it has a chain of seven terrestrial Earth-like planets located close to or in its habitable zone. In this paper, we study the effect of potential cometary impacts on the TRAPPIST-1 planets and how they would affect the primordial atmospheres of these planets. We consider both atmospheric mass loss and volatile delivery with a view to assessing whether any sort of life has a chance to develop. We ran N-body simulations to investigate the orbital evolution of potential impacting comets, to determine which planets are more likely to be impacted and the distributions of impact velocities. We consider three scenarios that could potentially throw comets into the inner region (i.e within 0.1au where the seven planets are located) from an (as yet undetected) outer belt similar to the Kuiper belt or an Oort cloud: Planet scattering, the Kozai-Lidov mechanism and Galactic tides.
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