Meteorite impacts identified as driver of moon's tenuous atmosphere

3/8/2024 11:23

        The NASA astronauts who became the first people to land on the moon's surface in the 1960s and 1970s also discovered a previously unknown lunar characteristic - it has an atmosphere, though quite tenuous. Soil samples they retrieved are now revealing the main physical process driving this atmosphere.
        By analyzing which forms of two elements - potassium and rubidium - were present in nine tiny soil samples from five Apollo missions, researchers determined that the lunar atmosphere was created and is sustained primarily by the effects of meteorites, large and small, striking the moon's surface.
        
        Massachusetts Institute of Technology planetary scientist and cosmochemist Nicole Nie, lead author of the study published on Friday in the journal Science Advances said, "Meteorite impacts generate high temperatures ranging from 2,000-6,000 degrees Celsius. These extreme temperatures melt and vaporize rocks on the lunar surface, similar to how heat vaporizes water, releasing atoms into the atmosphere."
        
        The lunar atmosphere is extremely thin and technically classified as an exosphere, meaning atoms do not collide with each other because their numbers are so sparse, in contrast to Earth's thick and stable atmosphere.