Earth’s Temporary ‘Mini Moon’ Set to Depart on Monday

A so-called “mini moon” that has been orbiting Earth for the past few months is about to drift away and resume its journey through the solar system.

The near-Earth asteroid, officially designated 2024 PT5, was first detected in early August using the NASA-funded ATLAS (Asteroid Terrestrial-impact Last Alert System) telescope in Sutherland, South Africa, operated by the University of Hawaii. Dubbed a “mini moon” due to its diminutive size—approximately 10 meters (33 feet) in diameter—and its brief stay in Earth’s gravitational embrace, the asteroid was never destined to remain a permanent satellite.

Throughout its temporary orbit, 2024 PT5 has maintained a distance from Earth about nine times that of the moon, posing no threat to our planet.

NASA scientists at the Center for Near Earth Object Studies (CNEOS) suggest the asteroid might be a fragment of lunar rock, ejected long ago during an asteroid impact on the moon. “Given the similarity between asteroid 2024 PT5’s motion and that of our planet’s, it is likely a piece of lunar history traveling through space,” NASA noted.

The asteroid’s departure, set for Monday, November 25, is governed by complex gravitational interactions among Earth, the moon, and the sun. These forces will guide it back to its original solar orbit.

Professor Carlos de la Fuente Marcos, who contributed to the discovery of 2024 PT5, explained its temporary nature, likening it to a “window shopper” rather than a committed “customer” in Earth’s vicinity. The asteroid is part of the Arjuna asteroid group, whose members follow Earth-like orbits around the sun at an average distance of 93 million miles (150 million kilometers).

Although 2024 PT5 will make a brief close approach in January 2025, it won’t return to Earth’s neighborhood until 2055, with another pass anticipated in 2084.

The fleeting visit of this cosmic traveler serves as a reminder of the dynamic and ever-changing environment of our solar system.