A small piece of space rock that lingered near Earth last year, which was dubbed its temporary “mini-moon” may have been a chunk of our actual moon that chipped off thousands of years ago.

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The small near-Earth asteroid 2024 PT5, which is only about 33 feet across, orbits around the Sun nearly in step with our planet. Its unusual path, which remains close to Earth without actually circling it, suggests that it may have formed in our neighbourhood.

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Familiar origin

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Researchers studying 2024 PT5 have observed new data, which hints that the rock originated from the Moon. They suspect that it was knocked off the lunar surface after a massive impact several thousands of years ago. It was then ejected and hurled into a path around the Sun, near Earth.

The asteroid can help offer rare information about the processes that designed the Moon.

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“We had a general idea that this asteroid may have come from the Moon, but the smoking gun was when we found out that it was rich in silicate minerals, not the kind seen on asteroids but found in lunar rock samples,” said Teddy Kareta, an astronomer at Lowell Observatory in Arizona, who led the study.

On observing how the asteroid reflects sunlight, it was found that its materials closely resemble that of the Moon, unlike typical asteroids.

On further evaluation of its orbit, the experts at NASA’s Center for Near Earth Object Studies (CNEOS) measured solar radiation pressure, which is the slight push from sunlight.

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“That 2024 PT5 doesn’t move this way indicates it is much denser than space debris,” said Oscar Fuentes-Muñoz, a NASA postdoctoral fellow at the Jet Propulsion Laboratory. In comparison, human-made debris is usually relatively light and more affected by the pressure of sunlight

A rare asteroid

The new findings revealed by NASA scientists revealed that 2024 PT5 is natural and has a composition unique to typical asteroids, ruling out the possibility that it is human-made.

The only other near-Earth asteroid confirmed to have originated from the Moon is 469219 Kamoʻoalewa, which was first identified in 2016.

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If scientists are able to link lunar craters to these objects, it may help reveal more about how impacts shape the Moon’s surface. 

Further exploration may also illuminate the processes that shaped the Moon and influenced Earth’s early environment.

(With inputs from agencies)