Near-Earth Object May Be a Broken Piece of Our Moon

A space object that orbits near Earth may actually be part of our moon that broke off in ancient times when an asteroid collided with it. Known as Kamo'oalewa, this mysterious space object was first noticed back in 2016.

Kamo'oalewa, which measures 40 meters in width (130 feet), is referred to as Earth’s quasi-satellite. It orbits the sun in a very similar pattern to our planet so it is always located fairly close to us. Its closest distance to us is approximately 40 times further than the moon. It is believed that it has been accompanying our planet for at least a century which is very odd as other quasi-satellites normally stay around for several months to a couple of years.

Vishnu Reddy, who is an associate professor in cosmochemistry and planetary astronomy at the University of Arizona, as well as PhD student Benjamin Sharkey have been studying the object and recently made a very interesting discovery. In an interview with Space.com, Reddy explained what they found, “We couldn't believe the way it was looking because it was unlike anything we've seen before,” adding that the object was very different from the other 2,000 near-Earth asteroids that have previously been studied.

By using the Large Binocular Telescope (this is one of the biggest optical telescopes in the United States) as well as the infrared Lowell Discovery Telescope, they were able to analyze how the space rock reflected light. They realized that the light spectra on Kamo'oalewa had a lot of common with samples collected from the moon in the 1960s and 1970s during the Apollo missions. In fact, 382 kilograms (842 pounds) of lunar samples were collected and brought back to Earth during six Apollo missions between 1969 and 1972.

Sharkey reiterated this by telling Space.com, “The spectral properties of this object look very similar to that of the moon.” “It's not that there couldn't be other asteroids [with such spectra], but we haven't found anything so far that looks similar to it.”

But considering its close proximity to our planet and our lunar companion, it’s very possible that Kamo'oalewa was once part of the moon. “If you look at the moon through a telescope, you see thousands of craters,” Reddy explained, “The material ejected during these impact events should be all over the place. But nobody has found it so far.”

China is planning to launch a mission in 2024 that will collect a sample from Kamo'oalewa and return it to Earth, so we may definitively find out in a few years if Reddy and Sharkey’s theory is correct. Their study was published in the journal Communications Earth & Environment where it can be read in full.

An artist’s impression of Kamo'oalewa can be seen here.