Last year, a small space rock that came near Earth was popularly termed a “mini-moon.” Interestingly, this lunar-inspired label might actually hold some truth.

The term “mini-moon” applies to objects that temporarily orbit around Earth at a certain distance or velocity, but it does not indicate their origin or composition. However, a new study suggests that this particular space rock may genuinely be a fragment of the moon.

The object garnered worldwide attention when it approached Earth closely enough between September and November to be designated a near-Earth object. Even though it didn’t pose any threat to our planet, it intrigued astronomers, who quickly set out to study it before it moved away.

Since its orbit closely resembled that of Earth, astronomers inferred that this so-called “mini-moon” likely originated from nearby in our solar system.

Recent research published in the Astrophysical Journal Letters indicates that the object, commonly referred to as a “mini-moon,” is likely made of lunar rock thrown into space by a significant impact on the moon thousands of years ago.

What was the ‘mini-moon’?

The asteroid, designated 2024 PT5, was first detected on August 7 by astronomers using the NASA-backed Asteroid Terrestrial-impact Last Alert System, or ATLAS.

With a size of approximately 33 feet, this object never truly entered Earth’s orbit and didn’t fit the criteria to be officially considered a “mini-moon.” Nevertheless, the nickname persisted.

From September 29 to November 25, it followed a horseshoe path that brought it near Earth before drifting away once again.

Study reveals 2024 PT5 may be from the moon’s surface

During this event, astronomer Teddy Kareta of Lowell Observatory in Arizona was among those trying to observe the object while they could.

Kareta and his team first spotted it on August 16 using the Lowell Discovery Telescope and the NASA Infrared Telescope Facility in Hawaii.

By analyzing its movement, the team quickly eliminated the possibility of it being man-made debris from old satellites or spacecraft.

They investigated how light reflected off the small asteroid and found that it didn’t resemble any known asteroid type. Instead, the reflection was more similar to rocks found on the moon.

This led to the conclusion that 2024 PT5 was likely ejected from the moon’s surface as a result of one of the many impacts that have created its signature craters.

“We had a general idea that this asteroid might originate from the moon, but we confirmed it when we discovered it was rich in silicate minerals—those found in lunar rock samples, rather than in asteroids,” Kareta remarked in a statement released by NASA announcing the findings.

“It appears to have recently entered space, possibly just a few thousand years ago, as it hasn’t experienced significant space weathering that would change its spectrum.”

This isn’t the first lunar-origin space rock

The discovery of 2024 PT5 marks it as the second known space rock potentially stemming from the lunar surface.

The asteroid 469219 Kamo’oalewa was discovered in 2016 and also appears to have been ejected from the moon due to a major impact.

Moreover, astronomers believe that more lunar rocks are yet to be discovered as advancements in telescope technology improve the detection of smaller asteroids.

If a lunar asteroid can be traced back to a specific impact crater on the moon, studying it may reveal new insights into the moon’s battered surface.

“This is a fascinating story told by asteroid scientists about the moon,” Kareta commented. “It’s a unique situation where our study of an asteroid unfolded into new avenues of inquiry regarding 2024 PT5.”

Eric Lagatta reports on breaking and trending stories.