New study suggests Earth’s recent minimoon originated from the moon

Near-Earth asteroid 2024 PT5 is in an Earth-like orbit and remained very close to Earth for several months at the end of 2024.

2024 PT was first detected on August 7, 2024 by the NASA-funded Asteroid Terrestrial Last Alert System (ATLAS) telescope at the University of Hawaii in Sutherland, South Africa.

This asteroid poses no danger to Earth, but its orbit around the sun closely matches that of our planet.

The object, which is about 10 meters (33 feet) wide, appears to be composed of rock that broke off from the moon’s surface and was ejected into space after a major impact.

“There was a general idea that this asteroid might have come from the moon, but when we discovered that this asteroid is rich in silicate minerals, it became conclusive proof. The silicate minerals are not the kind found on asteroids, but rather the ones found in the moon’s rocks. Dr. Teddy Kaleta Astronomer at Lowell Observatory.

“It doesn’t seem to have been in space very long, perhaps only a few thousand years, because there was no cosmic weathering to cause its spectrum to turn red.”

Using observations from the Lowell Discovery Telescope and NASA’s Infrared Telescope Facility (IRTF) at Mauna Kea Observatory in Hawaii, Dr. Kaleta and his colleagues show that the spectrum of sunlight reflected from the surface of 2024 PT does not match its spectrum. showed. A known asteroid type. Instead, the reflected light more closely matched the moon’s rocks.

This discovery doubles the number of known asteroids thought to originate from the Moon.

“Asteroid 469219 Kamooarewa was discovered in 2016 in an Earth-like orbit around the sun, indicating that this asteroid may also have been ejected from the lunar surface after a major impact,” the astronomers said. said.

“As telescopes become more sensitive to smaller asteroids, more potential lunar boulders will be discovered, and scientists studying the moon as well as scientists studying rare asteroid populations will It creates exciting opportunities for everyone.”

“If a lunar asteroid could be directly related to a specific impact crater on the Moon, studying it could provide insight into the cratering process on the pockmarked lunar surface.”

“Also, material collected from deep on the moon’s surface in the form of asteroids passing close to Earth could be available to future scientists for study.”

“This is a story about the moon told by asteroid scientists,” Dr. Kaleta said.

“It’s an unusual situation where we go out to study asteroids and end up wandering into new territory in terms of the questions we can ask for PT5 in 2024.”

of findings On January 14, 2025, Astrophysics Journal Letter.

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Theodore Caleta others. 2025. On the origin of the near-Earth asteroid moon2024 PT5. APJL 979, L8; doi: 10.3847/2041-8213/ad9ea8