The Moon is not the only natural object travelling through space alongside Earth. Several small asteroids travel around the Sun in near lockstep with our planet. And just like Earth, these space rocks also take a year to complete a full orbit. Today, we know of eight such “quasi-moons” or quasi-satellites.

One of them may, in fact, be a fragment of the Moon itself.

This intriguing quasi-satellite is known as 469219 Kamo'oalewa or “oscillating celestial object” in Hawaiian, a nod to its apparent path across the sky. Measuring between 30 and 60 metres across, it follows a remarkably stable Earth-like orbit around the Sun.

But scientists are keen to explore the asteroid in detail for other reasons than its unusual orbit. A Chinese spacecraft is about to fetch a sample so we can learn more.

Heavily debated origin

Based on the way it absorbs and reflects light, Kamo'oalewa was thought to be a chunk of lunar material that a meteor impact ejected from the Moon’s surface long ago.

However, more recent analysis suggests it may simply be a common type of stony asteroid, a so-called LL chondrite, whose surface has been severely weathered by the harsh space environment.

To shed light on this confounding mystery, in May 2025 the China National Space Administration launched a scientific probe, Tianwen-2, an ambitious mission to study the asteroid at........

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