Earth's temporary 'mini-moon' might be lost fragment of the Moon
What's the story
A small asteroid, referred to as Earth's temporary "mini-moon," could actually be a piece of the Moon that broke away thousands of years ago.
The celestial object, called 2024 PT5, is about 10-meter wide and poses no threat of collision with Earth now or in the near future, thanks to its trajectory.
After closely approaching Earth, it is moving away on a new, more distant orbit.
Orbital similarity
The asteroid's orbit mirrors Earth's
Interestingly, 2024 PT5's orbit around the Sun closely resembles that of Earth, prompting researchers to believe that it came from our part of the solar system.
The asteroid was first detected on August 7 2024, using the South Africa-based observatory of NASA-funded Asteroid Terrestrial-impact Last Alert System (ATLAS).
Despite initial predictions of it becoming a temporary mini-moon, it maintained a horseshoe orbit bringing it close without actually entering into an orbit around our planet.
Unique path
2024 PT5's unique trajectory
Dr. Teddy Kareta, a postdoctoral associate at Lowell Observatory in Arizona, explained that the object never really orbited Earth but had its path slightly altered by a very close approach with the Earth-Moon system.
He further stated that this kind of orbit is fundamentally rare and doesn't have a generic term yet due to its uniqueness.
The team's observations indicated that as sunlight reflected off 2024 PT5's surface, it appeared very similar to rocks collected from the lunar surface.
Lunar link
Its composition supports lunar origin theory
The team found the asteroid to be rich in silicate minerals, which are not usually seen on asteroids but are present in lunar rock samples.
Kareta said, "It looks like it hasn't been in space for very long, maybe just a few thousand years or so."
This supports the theory of its lunar origin and helps us understand a rare but growing population of lunar asteroids.
Confirmation
2024 PT5 confirmed as space rock, not debris
To ensure 2024 PT5 wasn't space junk like an old rocket, the team studied the object's movement.
NASA's Center for Near Earth Object Studies (CNEOS) scientists calculated the movement of 2024 PT5 and confirmed it was a space rock.
"That 2024 PT5 doesn't move this way indicates it is much denser than space debris," said study co-author Oscar Fuentes-Munoz, a postdoctoral fellow at NASA's Jet Propulsion Laboratory who worked with CNEOS researchers.
Expert consensus
Experts support lunar origin theory for 2024 PT5
Robert Jedicke, who is a specialist emeritus on solar system bodies at the University of Hawaii's Institute for Astronomy, finds the argument that 2024 PT5 is of lunar origin convincing.
This is because the study authors "have performed an exhaustive analysis of all reasonable options."
He stated in an email, "It is expected that some objects launched off the moon by an asteroid or comet impact would evolve into these kinds of orbits."