The Moon has no breathable air, but it does have a thin atmosphere. which would be the result of the impact of micrometeorites over billions of years, in a process explained by a study published in Science Advances.
A team from the Massachusetts Institute of Technology (MIT) and the University of Chicago in the United States claims that The process that formed the atmosphere of our satellite and still maintains it is mainly vaporization by contact during the impact of meteorites..
The researchers studied samples of lunar soil taken by astronauts on the Apollo missions and data from NASA’s LADEE lunar orbiter, the latter designed to determine the origins of the satellite’s atmosphere.
The Moon, bombarded by meteorites
Analysis suggests that, Throughout the Moon’s 4.5 billion-year history, its surface has been continually bombardedfirst by massive meteorites and, more recently, by smaller, dust-sized micrometeorites.
These impacts lift the lunar soil, vaporizing certain atoms on contact and launching the particles into the air. While some are ejected into space, others remain suspended, forming a thin atmosphere that is constantly renewed as the meteorites continue to hit the surface.
“We provide a definitive answer that vaporization by meteorite impact is the dominant process creating the lunar atmosphere,” said lead author Nicole Nie of MIT in a statement.
Vaporization and spraying
Data from the LADEE mission, launched in 2013, indicate that Two processes play a role in the creation of the lunar atmosphere: impact vaporization and ion sputtering..
Sputtering is a phenomenon related to the solar wind, which carries energetic particles from the Sun through space. When these particles hit the lunar surface, they can transfer their energy to atoms on the ground and send them flying.
To more precisely determine the origins of the lunar atmosphere, The team used ten samples of lunar soil to first try to isolate two elements from each sample: potassium and rubidium.Both elements are “volatile,” meaning they are easily vaporized by impact and ion spray.
The team analyzed the presence of potassium and rubidium isotopes. Each element exists in the form of several isotopes, which are variations of the same element, with the same number of protons, but slightly different neutrons.
The scientists analyzed the theory that impact vaporization and ion sputtering should result in very different isotopic ratios in the soil.
The specific ratio of light to heavy isotopes remaining in the soil, for both potassium and rubidium, should reveal the main process contributing to the origins of the lunar atmosphere.
Analysis of lunar soil samples showed that the surface contained mainly heavy isotopes of potassium and rubidium.
Using models, the researchers quantified the ratio of heavy to light isotopes of potassium and rubidium and, by comparing the two elements, found that impact vaporization was “most likely the dominant process by which atoms vaporize and rise to form the lunar atmosphere,” the study notes.
“With impact vaporization, most atoms would remain in the lunar atmosphere, while with sputtering, many atoms would be ejected into space,” Nie said.
Finally, the team quantified the contribution of both processes and established that 70% or more of the lunar atmosphere is the product of meteorite impactswhile the remaining 30 percent is a result of the solar wind.
FEW (EFE, Science Advances)