Lunar atmosphere

Abstract

A rarified atmosphere should be present on the moon because of contributions from the solar wind, meteoric volatilization, and internal degassing. Transient contributions to the atmosphere must be produced by rocket gases during lunar missions. These gases may obscure the ambient atmosphere in the vicinity of the landing site for a period of several months after a lunar landing. Of the three natural sources, definite predictions can be made only on the basis of solar wind input. The lunar atmosphere of solar origin is expected to consist mainly of neon, lighter gases being less prevalent because of their more rapid thermal escape and leaves gases less prevalent because of their lesser concentrations in the solar wind. Daytime néon concentrations are expected to be near 6 × 10⁴ cm⁻³, and nighttime concentrations are expected to be near 1.5 × 10⁶ cm⁻³.