Kamooalewa May Not Be a Piece of the Moon, New Study Says
A Chinese team in Nature Communications challenges the idea that asteroid Kamooalewa broke off the Moon and proposes a main asteroid belt origin, weeks before the probe arrives.
- A new Chinese study in Nature Communications challenges the assumption that asteroid Kamooalewa is a chunk torn from the Moon.
- The team used a laser on meteorite dust and reproduced the reddish color seen on Kamooalewa, pointing to an LL chondrite rather than lunar material.
- The proposed origin is the Flora asteroid family in the inner main belt, with a surface similar to asteroid Itokawa.
- The Tianwen-2 probe enters orbit around Kamooalewa in mid-June 2026, with sampling planned for July.
Asteroid Kamooalewa, the first target of China’s Tianwen-2 mission, may not be a piece of the Moon after all. A study led by Yang Li of the Chinese Academy of Sciences, published on June 2, 2026, in the journal Nature Communications, questions the widely held assumption that this tiny object formed from an impact that ejected material off the lunar surface. Instead, the authors propose that the body comes from the main asteroid belt between Mars and Jupiter.
The result arrives only weeks before the spacecraft is due to reach its target. The question of origin is no academic footnote, since it shapes how scientists will interpret the sample the mission plans to return to Earth in late 2027.
What exactly does the laser experiment show?
In the laboratory, the team fired a laser at meteorite dust to reproduce so-called space weathering, the process by which radiation and micrometeorites gradually alter the surface of an exposed body. After treatment, the sample took on a reddish color that matches what telescopes see on Kamooalewa.
According to the study, that color best fits an LL chondrite, a common type of stony meteorite, rather than the composition of lunar rock. Based on the spectral properties, the authors propose a specific origin:
- the Flora asteroid family in the inner part of the main belt
- a surface similar to asteroid Itokawa, which Japan’s Hayabusa probe visited in 2005
- a mineral makeup close to stony rather than lunar bodies
It is worth marking the limit of this conclusion. The authors do not claim a lunar origin is impossible, only that the observed data fit the main belt scenario better.
We do not entirely close the door on a lunar composition, the study authors state.
Why does it matter what Tianwen-2 finds?
Kamooalewa is a quasi-satellite of Earth, a body less than 100 meters across that accompanies our planet on its orbit around the Sun. It was discovered by the PanSTARRS telescope in 2016, and its estimated rotation period is about 28 minutes, placing it among the fast rotators of that size.
The Tianwen-2 mission launched in May 2025. Under the plan, the probe enters orbit around the asteroid in mid-June 2026, sampling is scheduled for July, and the return capsule is expected back on Earth in late 2027. Direct measurements on site and, later, laboratory analysis of the sample could settle a debate that for now is argued indirectly, through color and spectrum.
Until that happens, both hypotheses remain open. The laser experiment is indirect evidence, useful but not decisive, because it reproduces surface conditions rather than the asteroid material itself. Do you think the sample Tianwen-2 brings back will confirm a stony or a lunar trail?
