A new study finds that long, long time ago volcanic activity spewed gas above the surface of the moon. Thus, remaining like that for 70 million years, giving moon atmosphere.

When we see moon today, we don’t see much of an atmosphere. But 3 to 4 billion years ago it may have had one, a study has found.

NASA’s Marshall Space Flight Center in Huntsville, Alabama, and the Lunar and Planetary Institute (LPI) in Houston suggests that the moon’s ancient volcanoes produced a temporary atmosphere.

Intense volcanic activity was pumping out massive amounts of gas as lava seas were filling the moon’s impact basins. Gas accumulated faster than they could escape to space, thus, giving rise to a lunar atmosphere.

NASA’s Solar System Exploration Research Virtual Institute supports this study.

Today, the lunar atmosphere is not technically an atmosphere because it’s extremely thin. Instead, it’s considered an “exosphere,” with molecules that remain on the moon due to gravity but are so rare to behave like a gas.

The researchers said, 3.8 and 3.5 billion years ago, lava seas once filled the moon’s Serenitatis and Imbrium basins.

Astronauts in the Apollo 15 and 17 missions explored the boundaries of these ancient lava seas. They collected samples that also tell of the eruptions that took place billions of years ago.

They revealed that magma beneath the lunar surface, billions of years ago, carried gas components, such as carbon monoxide, the ingredients for water, sulfur, and other volatile species, LPI officials said in a statement.

LPI officials said that the findings may have big implications for future exploration of the moon, because it “quantifies a possible trapped source of volatiles 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.”

So, the new findings could dramatically reshape our understanding of the moon.