The moon may have had an atmosphere 3 to 4 billion years ago, when giant clouds of gas above the lunar surface were spewed by volcanic eruptions.
The moon’s surface is covered in dead volcanoes and dark maria, or plains that consist of hardened lava. Technically, the lunar atmosphere is not considered an atmosphere rather an exosphere, due to the fact that it is so thin with molecules that are bound to the moon’s gravity but are too sparse to behave like a gas.
A new study, published in Earth and Planetary Science Letters, suggests that the ancient volcanoes on the moon produced a temporary atmosphere that persisted for 70 million years before escaping into space. Lunar and Planetary Institute officials said in a statement, that samples of volcanic glasses collected by Apollo astronauts in the 1970s showed that magma beneath the lunar surface “carried gas components billions of years ago, such as carbon monoxide, the ingredients for water, sulfur and other volatile species.”
The study was carried by scientists at NASA’s Marshall Space Flight Center in Huntsville, Alabama and the Lunar and Planetary Institute (LPI). After calculating how much gas rose from the lava that flowed from the lunar volcanoes, researchers ruled that enough gases concentrated around the moon to form an atmosphere, and that it grew faster than it could dissipate into space.
LPI officials said that the findings may have big implications for future exploration of the moon, because it “quantifies a source of volatile(s) that may have been trapped from the atmosphere into cold, permanently shadowed regions near the lunar poles and, thus, may provide a source of ice suitable for a sustained lunar exploration program.”