Earth May Have At Least Six "Minimoons" At Any Given Time: Study

Scientists estimate that Earth may have at least six "minimoons" at any given time. Notably, this number is uncertain, and the researchers have called for further observations to confirm. As per the study published in the journal Icarus, the minimoon is a colloquial term for natural objects that complete an orbit around the Earth within a geocentric distance of three Earth Hill radii while being temporarily bound in the Earth-Moon system (EMS).

Also Read | Soil On The Moon Could Potentially Support Life, Study Claims

Scientists said minimoons are small, rocky fragments that temporarily orbit Earth before eventually moving on to circle the sun. They're usually less than 6.5 feet (2 metres) in size and can originate from various areas in the solar system, the study revealed.

Robert Jedicke, a researcher at the University of Hawaii and lead author of the study, told Space.com that it's "kind of like a square dance, where partners change regularly and sometimes leave the dance floor for a while."

The research suggests that minimoons may come from the Moon rather than the asteroid belt, as previously thought. This theory is supported by the discovery of minimoons with lunar-like compositions, such as 2024 PT5.

Also Read | New Study Reveals Uranus Generates Its Own Internal Heat

It's difficult to detect minimoons because of their small size and high speeds. As per the research, they can complete one rotation in under an hour and may showcase unique orbital patterns.

"Detecting objects in that size range means they have to be close so they are bright, but if they are close, it means they also appear to be moving quickly across the sky," Jedicke said. "It is incredible that modern telescopic surveys have the ability to detect such small objects up to millions of kilometres away."

Studying minimoons can provide insights into the Moon's history and crater formation process. They could also have commercial applications, such as resource extraction. Minimoons "may help reveal how the solar system formed and continues to evolve," Jedicke said