A model of the primordial lunar atmosphere

• Published in: Earth and planetary science letters Vol. 474; pp. 198 - 205
• Main Authors: Saxena, Prabal, Elkins-Tanton, Lindy, Petro, Noah, Mandell, Avi
• Format: Journal Article
• Language: English
• Published: Goddard Space Flight Center Elsevier B.V 15.09.2017; Elsevier
• Subjects: asymmetry; atmosphere; Lunar And Planetary Science And Exploration; magma ocean; Moon; Oceanography; wave generation; atmosphere; asymmetry; magma ocean; Moon; wave generation; Moo
• ISSN: 0012-821X; 1385-013X
• DOI: 10.1016/j.epsl.2017.06.031

We create the first quantitative model for the early lunar atmosphere, coupled with a magma ocean crystallization model. Immediately after formation, the moon's surface was subject to a radiative environment that included contributions from the early Sun, a post-impact Earth that radiated like a mid-type M dwarf star, and a cooling global magma ocean. This radiative environment resulted in a largely Earth-side atmosphere on the Moon, ranging from ∼104 to ∼102 pascals, composed of heavy volatiles (Na and SiO). This atmosphere persisted through lid formation and was additionally characterized by supersonic winds that transported significant quantities of moderate volatiles and likely generated magma ocean waves. The existence of this atmosphere may have influenced the distribution of some moderate volatiles and created temperature asymmetries which influenced ocean flow and cooling. Such asymmetries may characterize young, tidally locked rocky bodies with global magma oceans and subject to intense irradiation. •We present the first spatially resolved model of the primordial lunar atmosphere.•The Moon likely possessed a moderate collapsing metal atmosphere until lid formation.•The atmosphere included supersonic winds that generated waves in the magma ocean.•Distribution/depletion of moderate volatiles may have been influenced by the atmosphere.•Extant evidence of these abundance asymmetries may provide a clue to moon formation.