Volcano in moon

Earth's moon doesn't have much of an atmosphere today. However, it may have had a more prominent atmosphere 3 billion to 4 billion years ago, when vocanic eruptions spewed giant clouds of gas above the lunar surface, a new study has found. 

Today's moon is covered in dead volcanoes and dark maria, or plains that consist of hardened lava. The Lunar atmosphere  is so thin it's not even technically an atmosphere — instead, it's considered an "exosphere," with molecules that are gravitationally bound to the moon but are too sparse to behave like a gas.