QUESTION:
Does it snow on Mars?

ANSWER:
(from Mike Mellon on March 31, 1997)
Probably, but we have not observed it. We do know that each winter carbon dioxide
(the primary gas in the atmosphere) condenses on the polar caps to form a thick layer
of carbon dioxide frost. This frost may fall from the sky as snow, landing on the polar
surface where it accumulates in a layer that can be as much as a couple of meters thick.

Snow as we know it on Earth (made from water) is unlikely. Although it is certainly cold
enough on Mars, there simply isn't enough evaporated water in the atmosphere to
form any significant amount of snow to fall to the ground. In other words, air on Mars is
too dry. There is, however, lots of water ice in the polar caps, but this water is probably
more like glacial ice than snow.


go bd