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© Copyright 1999, Jim Loy
In a Dick Tracy comic strip, many years ago, it was predicted that a flag on the moon would wave in the breeze. The idea was that although the moon's atmosphere may be almost nonexistent, its gravity (pulling the flag downward) is very weak as well. And these effects would tend to cancel each other out. Even back then, astronomers knew that the moon's atmosphere, if it had any at all, was very very thin, not dense enough to cause even a ripple in a flag. And astronomers knew that the moon's gravity is 1/6 that of earth's gravity. Compared to the effect of such a thin atmosphere, the moon's gravity is very strong.
Theoretically, the moon does have a very thin atmosphere, which probably varies from place to place. Seismic activity (relatively rare) probably vents gasses occasionally. And meteors probably vaporize all kinds of substances, temporarily. In the heat of the day, gasses probably leak into space (because the weak gravity is not strong enough to hold it). At the poles, there are craters and other holes which are always in the shade. Some of these may have a significantly thicker atmosphere.