Earth has gained a new “mini-moon” after an asteroid, named 2024 PT5, entered its orbit.
The asteroid has been trailing Earth for years but has recently come close enough to be captured by our planet’s gravity. It will remain in Earth’s orbit until November, after which it will break free and continue its journey around the Sun.
Mini-moons form when an asteroid approaches Earth in such a way that our planet’s gravity temporarily overpowers the Sun’s pull. These objects are usually natural, like asteroids or space debris, but sometimes human-made space junk can also be caught in Earth’s gravity.
2024 PT5, discovered last month by the Asteroid Terrestrial-Impact Last Alert System, is not considered a threat to Earth. The system is designed to detect near-Earth objects that could pose a danger, but this mini-moon is harmless. The discovery was detailed in a paper published in Research Notes of the AAS titled “A Two-month Mini-moon,” where researchers predicted the asteroid would follow a horseshoe-shaped path before leaving Earth’s orbit around November 25. It is expected to depart from Earth’s vicinity in January and may return in 2055.
Although it can be observed with specialized telescopes, 2024 PT5 is too small and faint to be seen with the naked eye. Like many asteroids that pass by Earth, it likely originated from the Arjuna belt, known for its smaller objects.
While it’s not unusual for Earth to attract small objects, it’s relatively rare for them to become mini-moons like 2024 PT5. A similar event occurred with 2022 NX1, which was briefly a mini-moon in 1981 and returned in 2022.
Other planets, like Jupiter, also have mini-moons due to their larger mass and stronger gravitational pull. Some planets can even have quasi-moons that orbit the Sun along similar paths to their host planets, which can attract mini-moons of their own.