A mysterious rock orbiting Earth appears to be a chunk of the moon that was blasted away by a meteorite

• A space rock with a peculiar orbit may be a floating piece of the moon.
• Scientists had thought moon rocks weren't able to stay in orbit after a meteorite blast.

A chunk of the moon that may have broken away from the lunar surface millions of years ago appears to be orbiting our planet.

The 'quasi-satellite,' named Kamo`oalewa, has baffled scientists for decades due, in part, to its peculiar orbit.

The rock, which is between 120 and 300 feet wide, technically orbits the sun every year. But on its travels, it also keeps the Earth company, slowly spiraling around our planet as it barrels through space.

Now, researchers at the University of Arizona believe they have evidence that it was likely created by an ancient lunar collision.

The discovery could rewrite what we know about potentially dangerous space rocks and help better protect our planet from a future a impact.

Kamoʻoalewa has been Earth's companion for at least a century

"This small asteroid is caught in a little dance with Earth," Paul Chodas, a NASA Near-Earth Object scientist at the Jet Propulsion Laboratory, previously said in a blog post.

The space rock "has been a stable quasi-satellite of Earth for almost a century, and it will continue to follow this pattern as Earth's companion for centuries to come," he added

This mesmerizing orbit, which poses no threat to Earth, means Kamoʻoalewa qualifies as a rare "quasi-satellite."

A study in 2021, which analyzed the light bouncing off the rock, found it was made of components that were remarkably similar to the stuff that makes up the moon's surface.

But physicists tend to think moon objects shouldn't find stable orbits — rocks that have enough energy to escape the moon's pull should be grabbed by Earth's gravity and plummet to their doom, per a press release by the University of Arizona.

Now, a new study, published in the peer-reviewed journal Communications Earth & Environment, seems to have cracked the mystery.

An advanced computer simulation, taking into account the properties of the sun, the moon, the Earth, and all other planets in the solar system, found that some lucky moon rocks could survive being blasted away from the lunar surface, provided they follow very specific rules.

Being blasted from the moon at about 1.5 miles per second is one of these rules, lending credence to the idea that this satellite was created by the impact of a meteorite.

The finding could change where we think potentially dangerous space rocks come from

Scientists are constantly monitoring the skies for potentially dangerous space rocks — but they are very aware of their limitations.

Some of the smaller rocks, for instance, can fly under the radar. Others can be occluded by the sun, which blinds the equipment we use to scan the universe for potential threats.

So to predict where the rocks may appear, scientists calculate how these rocks move through space from their most likely origin. These are usually thought to be the asteroid belt between Mars and Jupiter or in the Kuiper belt in the outer solar system.

"This brings up the need to consider other origin scenarios, in particular, that it may have originated as a lunar fragment from a meteoroid impact on the moon," said study author Jose Daniel Castro-Cisneros, a PhD student at the University of Arizona, in a blog post.

Space rocks like these also provide rare snapshots into the past of our solar system.

Because of its stable orbit around the Earth, it may be worth thinking about sending a mission to Kamoʻoalewa to understand more about our longtime neighbor, said Castro Cisneros.