Earth To Get New 'Mini-Moon': All About Asteroid 2024 PT5 Set To Join Orbit For 2 Months

The asteroid 2024 PT5 was spotted using the Asteroid Terrestrial-Impact Last Alert System (ATLAS) on August 7, 2024. It will stay in the Earth's orbit for almost two months.

Earth will have a new 'mini-moon' named 2024 PT5 for almost two months between September 29 and November 25 this year.

Source : Pixabay

In a rare event, Earth will soon have two moons for a brief period of nearly two months as our planet's moon will be accompanied by a new "mini-moon" between September 29 to November 25 this year. 

This junior companion, named 2024 PT5, was discovered using the Asteroid Terrestrial-Impact Last Alert System (ATLAS) on August 7, 2024. The ATLAS is a NASA-funded asteroid impact early warning system. However, this mini-moon is not a permanent natural satellite like the moon but is rather a temporarily captured flyby.

There are several Near-Earth Objects (NEOs) that approach our planet at a close range with a low relative velocity. These NEOs undergo mini-moon events wherein their own geocentric energy is lost for days, and sometimes months as it becomes negative. During this period, these objects orbit around the planet, following horseshoe paths, without completing one revolution while they are Earth-bound.

Similarly, the recently discovered 2024 PT5 will follow a horseshoe path and will become a mini-moon from September 29 until November 5. After 53 days, the asteroid will return to its regular heliocentric trajectory.

According to a report published in the Research Notes of the American Astronomical Society, the asteroid has a diametre of just 10 metre (33 feet). The report, authored by Carlos de la Fuente Marcos and Raul de la Fuente Marcos also noted the Earth's tendency to capture asteroids from the NEOs population regularly, pulling them into their orbit, and turning them into mini-moons.

While temporarily captured flybys do not get to complete even a single revolution, there are other temporarily captured orbiters that are able to complete one or more. 

Previous NEOs Captured By Earth

In July 2006, a temporarily captured orbiter named 2006  RH120  remained bound to Earth for a year till July 2007. Another 2020 CD3 escaped early in May 2020 after being bound to Earth for several years.   

Earth has also been accompanied by temporarily captured flybys in the past. A 1991 VG was captured in February 1992. Thereafter, a 2022 NX1, which was a short-lived mini-moon in 1981 and 2022. It revolved around the Earth but never completed an orbit. The report states that it is likely to return to the Earth in 2051 to take another semi-round.

About 2024 PT5

The recently discovered Apollo-class NEO 2024 PT5 is following the path that resembles the one followed by the 2022 NX1. It is larger than all the previous NEOs-- 2020 CD3, 2006 RH120, 1991 VG, and 2022 NX1. 

2024 PT5 is unlikely to be artificial as "its short-term dynamical evolution closely resembles that of 2022 NX1, a confirmed natural object". The object's orbital characteristics also resemble that of the asteroids that come towards the Earth from the Arjuna asteroid belt, the RNASS report noted.