Earth Might Host Six ‘Minimoons’ Orbiting Simultaneously

Recent studies indicate that at any moment, Earth could temporarily capture up to six fragments from the Moon, referred to as “minimoons,” before they return to their orbits around the sun.

However, their small size and swift velocity make these objects challenging to identify, according to a report from Space.com.

When meteoroids collide with the Moon, they can eject debris into space. While some larger fragments may be projected outward, the majority are relatively small—typically under 6.5 feet (2 meters) in diameter—and move at high speeds. Most of this lunar debris eventually settles into solar orbits, but occasionally, some pieces are briefly caught in Earth’s gravitational field before continuing their journey around the sun. This is detailed in a study published in the journal Icarus.

“It’s a bit like a square dance where partners frequently change and sometimes step off the dance floor for a while,” explained Robert Jedicke, a University of Hawaii researcher and the lead author of the study, in an email to Space.com.

While the International Astronomical Union hasn’t established a formal definition for “minimoons,” previous research suggests it refers to any object that is temporarily gravitationally bound to Earth, completes at least one orbit, and comes within approximately four times the average distance between the Earth and the Moon.

Minimoons can originate from various locations within the solar system. However, a study from 2018 proposed that most of them come from the asteroid belt situated between Mars and Jupiter. Recent discoveries of minimoons with apparent origins from the Moon are starting to challenge this assumption.

In 2016, the Pan-STARRS1 telescope in Hawaii identified a near-Earth object named Kamo’oalewa (or 469219 Kamo’oalewa), which measures between 131 and 328 feet (40 to 100 meters) in width.

Though it shares an orbit with Earth, further investigations have suggested that it likely originated from the Moon, possibly having been ejected during the impact that formed the Giordano Bruno crater 1 to 10 million years ago.

More recently, astronomers reported the discovery of another temporary Earth satellite, designated 2024 PT5, which was found last year. Its composition appears to be more similar to the Moon rather than that of an asteroid, lending further support to the idea that some minimoons may be fragments of lunar material.