This article has been updated with new details.

Earth is about to gain a mini-moon for a short time.

Researchers recently published a study in the AAS Research Notes discussing the mini-moon and its expected orbit around Earth.

The small asteroid, initially spotted on August 7 by the Asteroid Terrestrial-impact Last Alert System (ATLAS), a NASA-funded project, is now referred to as asteroid 2024 PT5. It is projected to enter Earth’s gravitational field from September 29 to November 25. Subsequently, it will break free from Earth’s orbit and head toward the sun, continuing its journey through our solar system.

Asteroid 2024 PT5’s Expected Path

Asteroid 2024 PT5 is estimated to follow a horseshoe-shaped path during its 56-day orbit before it departs from Earth’s gravitational influence.

However, it may be challenging to catch a sight of the tiny moon as it approaches Earth. According to the NASA JPL Small-Body Database, 2024 PT5 will be too faint for most amateur astronomers to observe, with an absolute magnitude of 22, making it too dim for standard backyard binoculars or telescopes.

The Origin of 2024 PT5

Asteroids can sometimes be drawn into Earth’s orbit due to the gravitational forces exerted by nearby planets. These celestial objects, like 2024 PT5, are classified as Near-Earth Objects (NEOs) by NASA. The Center for Near Earth Object Studies (CNEOS) at NASA’s Jet Propulsion Laboratory (JPL) estimates there are over 35,000 NEOs, with 99% being comprised of asteroids.

Researchers believe that 2024 PT5 originated from the Arjuna asteroid belt, which contains numerous small asteroids that follow stable, Earth-like orbits, as noted by Astronomy & Astrophysics.

Size of the Mini-Moon 2024 PT5

In contrast to Earth’s moon, which has a diameter of 2,159 miles, asteroid 2024 PT5 is merely about 33 feet across—roughly the length of a city bus.

This is not the first time Earth has had a mini-moon. 2024 PT5 shares a similar trajectory with asteroid 2022 NX1, also around 33 feet wide, which momentarily orbited Earth in 1981 and 2022. The asteroid 2022 NX1 is expected to return as a transient mini-moon in 2051, according to EarthSky.org.

We will see 2024 PT5 again, as it is projected to reappear in 2055, based on information from UniverseToday.com.

CONTRIBUTOR: Jim Sergent

SOURCES: NASA, Asteroid Terrestrial-impact Last Alert System, EarthSky.org, UniverseToday.com, Astronomy & Astrophysics, and the European Space Agency