why is it that the Earths moon has no atmosphere ?since it is one of the largest moons in the solar system?

Answer 1

There actually is a very thin atmosphere on the moon, not sufficient to support human life as you know. Of the known moons in the solar system, four have been found to have atmospheres: Jupiter's volcanically active moon Io (tenuous sulfur dioxide), Jupiter's ice-coated moon Europa (tenuous oxygen), Saturn's largest moon Titan (dense nitrogen and methane), and Neptune's largest moon Triton (tenuous nitrogen and methane). The ability of a moon to retain an atmosphere is related to its mass and its distance from the Sun, although tenuous atmospheres may be regenerated by a variety of processes.

Answer 2

The Moon does have an atmosphere... it is very tenuous... similar to but thinner than the Stratosphere of Earth.

The lunar missions increased the mass of the lunar atmosphere by 30%, which was enough to impact the sensitivity of some of the experiments. After several weeks the atmophere returned to normal having been swept clean by the solar wind that keeps it in relative stasis.


Here's a quote from the Apollo 17 Lunar Atmospheric Composition Experiment report:

"The Moon has an atmosphere, but it is very tenuous. Gases in the lunar atmosphere are easily lost to space. Because of the Moon's low gravity, light atoms such as helium receive enough energy from solar heating so that they escape in just a few hours. Heavier atoms take longer to escape, but are ultimately ionized by the Sun's ultraviolet radiation, after which they are carried away from the Moon by the solar wind. This process takes a few months. Because of the rate at which atoms escape from the lunar atmosphere, there must be a continuous source of particles to maintain even a tenuous atmosphere. Sources for the lunar atmosphere include capture of particles from the solar wind and of material released from the impact of comets and meteorites. For some atoms, particularly helium-4 and argon-40, outgassing from the Moon's interior may also be a source."

Answer 3

because its escape velocity isnt strong enough to hold particles on to it...therefore it cant have an atmosphere