Scientists have determined why the Moon still has an atmosphere

Due to its relatively small mass, the Moon has no breathable air, but the Earth’s satellite does have a barely noticeable atmosphere.

.in_text_content_22 { width: 300px; height: 600px; } @media(min-width: 600px) { .in_text_content_22 { width: 580px; height: 400px; } }

Since the 1980s, astronomers have been observing a very thin layer of atoms bouncing around the surface of the Moon. This wispy atmosphere — technically known as the “exosphere” — is likely the product of some kind of cosmic weathering, but its precise origins have eluded scientists, according to the Massachusetts Institute of Technology (MIT).

Previously, scientists assumed that two processes of space weathering were involved in the formation of the lunar atmosphere:

• “impact evaporation” as a result of the collision of micrometeorites with the Moon;
• “ion sputtering” is a phenomenon involving the solar wind, which carries energetic charged particles from the sun through space. When these particles hit the moon’s surface, they can transfer their energy to atoms in the soil and send those atoms flying into the air.

Now, a team of scientists from MIT and the University of Chicago say they have identified the underlying process that formed the moon’s atmosphere and continues to sustain it today.

According to the researchers, the Moon’s atmosphere is primarily a product of “impact evaporation.”

“With impact evaporation, most of the atoms will remain in the lunar atmosphere, whereas with ion sputtering, many atoms will be ejected into space,” the scientists note. “From our study, we can now quantify the role of both processes to say that the relative contribution of impact evaporation versus ion sputtering is about 70:30 or more.”

In other words, 70 percent or more of the Moon’s atmosphere is the product of meteorite impacts, while the remaining 30 percent is the result of solar wind.

In the study, scientists analyzed lunar soil samples collected by astronauts during NASA’s Apollo missions. Their analysis showed that:

• During the Moon’s 4.5 billion-year history, its surface has been continuously bombarded, first by massive meteorites and later by smaller, dust-sized “micrometeoroids”;
• These constant impacts stir up the lunar soil, vaporizing certain atoms on contact and lifting the particles into the air. Some atoms are ejected into space, while others remain suspended above the Moon, forming a constantly replenished, tenuous atmosphere as meteorites continue to fall to the surface.
• Impact evaporation is the primary process by which the Moon has created and maintained its extremely thin atmosphere over billions of years.

The Moon is about 4.5 billion years old, and during that time its surface has been continuously bombarded by meteorites. We show that the thin atmosphere is finally reaching a stable state, as it is constantly replenished by small impacts all over the Moon, the researchers note.

Source: Racurs

David

I am David Wyatt, a professional writer and journalist for Buna Times. I specialize in the world section of news coverage, where I bring to light stories and issues that affect us globally. As a graduate of Journalism, I have always had the passion to spread knowledge through writing.