Asteroid 2024 PT5 Study Says Earth’s ‘Mini-Moon’ Might Be a Lost Piece of the Big Moon

A temporary ‘mini-moon’, a tiny celestial body orbiting near Earth, might not be an ordinary space rock. A recent study suggests Asteroid 2024 PT5 could be a fragment of our Moon, likely ejected during an ancient impact. Nicknamed a “mini-moon,” 2024 PT5 occasionally gets captured by Earth’s gravity before continuing its journey.

Earth’s Mini-Moon Might Be a Lost Lunar Fragment, Asteroid 2024 PT5 Study Finds

New research suggests this “mini-moon” orbiting near Earth could actually be a fragment of our Moon, ejected during a violent impact in the distant past. The team of researchers says the mini-moon is something in between an S-type asteroid, made of silicates and metal, and a V-type like Vesta, the second-largest object in the main asteroid belt.

Measuring just 10 meters in diameter, 2024 PT5 occasionally becomes gravitationally “trapped” by Earth, briefly orbiting our planet before continuing its cosmic journey. Observations using the Gran Telescopio Canarias and the Two-meter Twin Telescope reveal that its surface is basaltic, a volcanic rock commonly found on the Moon. This indicates 2024 PT5 might be a piece of the Moon ejected during a major impact.

Asteroid 2024 PT5 has flown partially around Earth since 29 September and will make its departure on 25 November.

Scientific value

This tiny object rotates quickly, completing a spin in less than an hour. Its behaviour as a temporary Earth companion — what scientists call a “co-orbital object” — is rare, making it an ideal candidate for future research.

Such mini-moons offer valuable opportunities for exploration, particularly for testing new space technologies or studying objects up close without venturing far from Earth. If indeed a lunar fragment, 2024 PT5 provides an extraordinary chance to learn more about the Moon’s violent past and the forces shaping our celestial neighbourhood.

While 2024 PT5 will soon leave Earth’s vicinity, its discovery highlights the fascinating and complex dynamics of near-Earth objects. Future missions could unlock more secrets about these fleeting visitors—and perhaps even uncover more fragments of the Moon wandering through space.

Read the full research findings here.