Density of the Lunar Atmosphere

The minimum possible density of the lunar atmosphere at the surface is shown to be essentially the value for the interplanetary medium. This value, when combined with the observed maximum, places the particle density between 10(3) and 10(6) per cubic centimeter, while the electron density must be about 10(3) to 10(4) per cubic centimeter. These results are markedly different from those recently obtained by Firsoff.