Starting at the end of September, Earth will experience a rare phenomenon: a temporary second moon. However, this situation won’t last long—less than two months—and it’s unlikely you’ll be able to see this second moon with the naked eye.
The object in question is an asteroid named 2024 PT5, which was discovered on August 7 by the Asteroid Terrestrial-Impact Last Alert System (ATLAS). This small asteroid, about 33 feet (10 meters) wide, is on a path where it will be briefly captured by Earth’s gravitational pull. Researchers Carlos and Raúl de la Fuente Marcos from Spain’s Universidad Complutense de Madrid have calculated that 2024 PT5 will orbit Earth from September 29 until November 25, completing just one orbit before it escapes back into space.
Asteroid 2024 PT5 Is Set To Be A Mini-Moon Of Earth – But Just For Two Monthshttps://t.co/czMFPegdoP
— IFLScience (@IFLScience) September 13, 2024
Despite the exciting prospect of a second moon, don’t expect to see 2024 PT5 with the naked eye. Even with a backyard telescope, the asteroid’s dim magnitude value of 22 makes it difficult to spot. For comparison, objects typically need a magnitude of 6 or lower to be visible without assistance.
While rare, the phenomenon of Earth temporarily having a second moon is not unheard of. A similar event occurred in July 2006, when another mini-moon orbited Earth for about a year. More recently, a mini-moon was observed orbiting the planet until May 2020. Occasionally, objects like asteroids get pulled into Earth’s gravitational field but escape before completing a full orbit. In 2020, scientists thought they had discovered another mini-moon, though the data was inconclusive.
The asteroid 2024 PT5 is believed to have originated in the Arjuna asteroid belt, a region filled with near-Earth objects that share a similar orbit to our planet. The researchers noted that this object is unlikely to be artificial since its trajectory closely mirrors that of 2022 NX1, another asteroid that temporarily became a mini-moon in both 1981 and 2022.
🌙😱 Mini-moon for two months: Our planet will have a temporary companion
At the end of September, the Earth will gain a temporary mini-moon. It will be asteroid 2024 PT5, which will be captured by the gravity of our planet for two months.
Learn more 👇https://t.co/QQJytfDYBw pic.twitter.com/2Ccl4fPZkz
— Universe Space Tech (@ust_magazine) September 13, 2024
If you miss 2024 PT5’s brief visit this year, you’ll have another chance to witness its presence—albeit indirectly—when it passes by Earth again on January 9, 2025. After that, the asteroid won’t make a close approach until 2055.
Key Points:
i. Earth will temporarily have a second “moon” from September 29 to November 25, 2024, in the form of asteroid 2024 PT5.
ii. The asteroid, only 33 feet wide, will be too small and dim to be seen with the naked eye or backyard telescopes.
iii. This rare “mini-moon” phenomenon has happened before, most recently in 2020, though it is uncommon.
iv. 2024 PT5 likely comes from the Arjuna asteroid belt and has a trajectory similar to other asteroids that have orbited Earth.
v. The asteroid will pass by Earth again in January 2025, but won’t make another close approach until 2055.
TL Holcomb – Reprinted with permission of Whatfinger News
