What is the humidity on Mars?

Answer 1

As near to absolute zero as can be, without actually BEING perfectly zero. In space, we can't measure the "pressure" of gasses or water vapor, because there are too few atoms, so we calculate (and if need be, count) the number of atoms or molecules per cubic meter.

Near the Earth, at the altitude that the ISS or Space Shuttle flies, there are still thousands of atoms per cubic meter, and some of them are water molecules. And sometimes a photon from the Sun will break apart a water molecule into a hydrogen ion and a hydroxyl ion. Further away from the Sun, the solar system is filled with the "solar wind", hydrogen and helium atoms pushed out from the Sun by light pressure. (Some of the Apollo astronauts have calculated that the lunar dust must be saturated with Helium-3 atoms, and that mining the He3 from the dust could be an incredible power source for the Earth; if we could build a series of space trucks capable of bringing it home! Think of running a Helium3 Mine on the Moon, and shipping the fuel back to Earth, to be fused in the Mr. Fusion reactors!

Further out in space, we believe that the number of gas particles per cubic meter will continue to decrease. but never reach zero, not even in the voids between the stars.

Answer 2

The humidity on Mars is extremely low, typically less than 1%. Mars has a very thin atmosphere that is mostly carbon dioxide, which cannot hold much moisture. This low humidity contributes to the planet's overall dry and arid conditions.

Answer 3

The humidity on mars is 1%. I am a professor at Duke university