Earth to Have Two Moons Soon—But Not How You Expect

Earth is about to gain a temporary second moon, though it will only last for a few weeks and might not be visible. Starting in late September, a small asteroid, named 2024 PT5, will be captured by Earth’s gravity and briefly orbit our planet for less than two months.

Discovered on August 7 by the Asteroid Terrestrial-Impact Last Alert System (ATLAS), 2024 PT5 is on a path that will cause it to be caught by Earth’s gravitational pull. According to researchers Carlos and Raúl de la Fuente Marcos from Spain’s Universidad Complutense de Madrid, the asteroid will begin orbiting Earth from September 29 until November 25, after which it will break free and continue its journey through space.

This isn’t the first time Earth has experienced a temporary second moon. As noted by Carlos and Marcos in a paper published in the Research Notes of the AAS, similar events have occurred before, though they are rare.

 

Has Earth had two moons before?

Yes, Earth has temporarily had two moons on at least two occasions. One instance was in July 2006, when a mini-moon orbited the planet for about a year. Another object was caught by Earth’s gravity and stayed until 2020. Such occurrences happen when objects from space get temporarily captured by Earth’s gravitational field.

In 2020, scientists detected what they believed was a mini-moon, but conclusive data was never found. The researchers are confident that 2024 PT5 is a natural celestial object, not an artificial one. They noted that its movement is similar to a previous mini-moon, 2022 NX1, which was also briefly captured by Earth in both 1981 and 2022.

Asteroid 2024 PT5 is thought to have originated from the Arjuna asteroid belt, a region where near-Earth objects with orbits similar to Earth’s are found. Amateur astronomer Tony Dunn shared a simulation on X, showing how the asteroid will approach and leave Earth’s orbit.

The asteroid will return close to Earth on January 9, 2025, but after that, it won’t come back until 2055.