(not at all good for life) It's very very thin with pressure as low as 3×10^−15. As for why, there are two broad reasons: the moon loses its atmosphere fast because of its low gravity, and its atmosphere is not topped up by vapour from free water (and other volatiles) and emission from volcanoes. Detectors left by Apollo astronauts have detected argon-40, helium-4, oxygen, methane, … Since 6 x 0.5 = 3.0 kilometers per second, and this is higher than the lunar escape velocity of 2.4 kilometers/sec, any atoms lighter than oxygen would have escaped the lunar atmosphere. In short, our atmosphere is here because of gravity. The moon's gravitational field was not strong enough to hold many gases when it was being formed.

6 years ago. Several elements have been detected in the lunar atmosphere. Why Doesn’t the Moon have an atmosphere? The moon does not have any liquid water because of the extreme temperatures. When Earth formed, about 4.5 billion years ago, the molten planet barely had an atmosphere. Our Moon doesn't have an atmosphere because it is too small and doesn't have a strong magnetic field. What makes Earth have an atmosphere and not the moon. The first, and probably more obvious one, is that Mars has less surface gravity than Earth, so it doesn't hold the gas to the surface as tightly. The moon has an atmosphere, it is just very very thin. The moon doesn't have enough mass and gravity to hold onto an atmosphere.

The moon is very much lighter than earth, and has so much less gravity that all the gas in the atmosphere escaped.

On the Moon, the average temperature of the atmosphere there would be about 240 Kelvins or so, and the typical speed of heavy oxygen atoms would be about 0.5 kilometers per second.
Trivia. Your instinct might be that this is a linear process- that since Mars has 1/3 the surface gravity as Earth, it should have 1/3 of the atmosphere as Earth, but it … Since the most widely accepted explanation of why Mars has such a thin atmosphere is it losing its magnetosphere as its core cooled and does not contain nearly as much metallic iron has the Earth’s, it would make sense that Titan would follow the same pattern since it … The gravity at the surface is 1,35 m/s² for Titan and 1,62 m/s² for the the Moon. It has gravity, it's made from the same material as the earth (because of that infamous collision with a lost 'flying' thing - that could be a fallow up question: how can something so big 'fly across our solar system without either being in orbit around our sun or having hit something before hitting earth.

Venus's current atmosphere is no exception either. and a mass of 7.35 X 10 to the 22 pwr. Any liquid water exposed to sunlight on the moon evaporates instantly and escapes into space.

While the common wisdom that the moon lacks an atmosphere has been part of general knowledge for years, a NASA document released in January 2014 indicates that the moon does have an atmosphere with gases like potassium and sodium which do not appear in the atmosphere of Venus, Mars or Earth. Relevance. 5 Answers.
Earth's primitive atmosphere had large amounts of carbon dioxide, as did the ancient Martian atmosphere. Answer Save. This is the best I can come up with. Why doesn't Mercury have an atmosphere?