It’s small, blurry, and shaped like a Corn Flake, but the image taken of Earth’s tiny “quasi” moon, Kamo'oalewa, is one for the family album.
China’s Tianwen-2 probe snapped the picture of the rock on July 2 from a distance of around 20 kilometers (about 12 miles), after completing a landmark 1 billion-km journey that began last year.
After spending the next nine months studying Kamo'oalewa from afar, the probe will attempt a first for China, swooping in close to suck up a sample of the asteroid’s dust to send back to Earth for closer study.
Also known as asteroid 2016HO3, Kamo'oalewa is little bigger than a suburban home at around 20 to 30 meters (no more than 65 feet) across. It’s so small, it was only spotted ten years ago by the PAN-STARRS1 survey telescope in Hawaii.
The unassuming chunk of rock orbits the Sun on a path that keeps it close to our planet, making it one of seven known quasi-satellites currently in our proximity.
“Close to our planet” is, of course, relative. Even at its closest approach a century ago, the asteroid was a touch over 12 million kilometers away – around 40 times further away than the Moon. It’s been gradually slipping out of our grip ever since.
But just where did this tiny companion come from?
In their 2024 Nature Astronomy article, a team of researchers suggested the asteroid is a chunk of the Moon thrown into orbit by the same impact that left the Giordano Bruno crater on the lunar far side.
While the way Kamo'oalewa reflects light makes it suspiciously Moon-like, recent experiments suggest the same spectrum could be explained by highly-weathered chondrite powder, suggesting it’s just a worn-down sibling of the other quasi-satellites in Earth’s family.
Whatever its origins, a close-up analysis of its material will almost certainly reveal more details about its past.
China’s retrieval of pristine asteroid dust will add to the growing library of space material collected by NASA’s OSIRIS-REx and Japan’s Hayabusa-2 missions. The samples returned by both of these missions continue to contribute valuable knowledge on the chemistry of our ancient Solar System.
Now that Tianwen-2 has arrived at its destination, it will commence its own study program, capturing critical data and maybe even sending back a few more snapshots of Earth’s tiny, if temporary, companion.
Source: Xinhua
Fact-checked by Bronwyn Thompson
