Earth’s moon will soon be joined by a “mini moon,” an asteroid measuring approximately 10 meters, roughly the size of a school bus. This mini moon, designated 2024 PT5, will swing by Earth on Sunday and be temporarily captured by our planet’s gravity, orbiting for about two months.
Astronomers at Complutense University of Madrid first identified the space rock in August using a powerful telescope situated in Sutherland, South Africa.
According to Richard Binzel, an astronomer at the Massachusetts Institute of Technology, these fleeting mini moons are likely more prevalent than we realize. The last known mini moon was detected in 2020. “This happens with some frequency, but we rarely see them because they’re very small and very hard to detect,” he noted. “Only recently has our survey capability reached the point of spotting them routinely.”
The discovery, made by Carlos de la Fuente Marcos and Raúl de la Fuente Marcos, was published by the American Astronomical Society. While this mini moon won’t be visible to the naked eye or through amateur telescopes, it “can be observed with relatively large, research-grade telescopes,” Carlos de la Fuente Marcos explained in an email.
Binzel, who was not part of the research team, mentioned that it remains unclear whether the space rock originated as an asteroid or was “a chunk of the moon that got blasted out.”
The mini moon is expected to circle Earth for nearly 57 days but will not complete a full orbit. It will depart on November 25, continuing its journey through space, with a predicted return in 2055.