Detection of radon emission at the edges of lunar maria with the apollo alpha-particle spectrometer

Science. 1974 Feb 1;183(4123):411-3. doi: 10.1126/science.183.4123.411.

Abstract

The distribution of radioactive polonium-210, a decay product of radon-222, shows enhanced concentrations at the edges of lunar maria. Enhancements are seen at the edges of Mare Fecunditatis, Mare Crisium, Mare Smythii. Mare Tranquillitatis, Mare Nubium, Mare Cognitum, and Oceanus Procellarum. The observation is indicative of the transient emission of radon gas from the perimeters of lunar maria.