The Atmosphere of the Moon

Abstract

The possible existence of a lunar atmosphere has both fascinated and challenged astronomers for hundreds of years. Galileo searched for evidence of clouds, and Kepler imagined an Earth-like climate. Landings during the Apollo era brought instruments that measured a weak atmospheric pressure. Decades later, new spectrographic and imaging instruments detected sodium and potassium gas that extended to surprisingly large distances, making the Moon’s gaseous environment appear as comet-like. The sources of the lunar atmosphere involve the impact of sunlight, solar wind plasma and meteors upon the surface to release atoms and perhaps molecules. Solar radiation and the gravitational influence of the Earth play dramatic roles in the subsequent evolution of the lunar atmosphere.