Did you know Earth is about to get a second moon? Well, it’s true—kind of! Starting at the end of September, a small asteroid named 2024 PT5 will be temporarily caught in Earth’s gravity, making it a “mini-moon.” Unlike our permanent moon, these mini-moons are small asteroids that only stay in Earth’s orbit for a brief time before they drift back into space.
2024 PT5 is a near-Earth asteroid that was discovered on August 7, 2024, using NASA’s Asteroid Terrestrial-Impact Last Alert System (ATLAS). This asteroid is about 33 feet (10 meters) wide, so it’s not huge, but it’s still big enough to be fascinating. From September 29, 2024, until November 25, 2024, Earth’s gravity will pull it in for a brief visit. It won’t complete a full orbit around our planet but will follow a kind of horseshoe-shaped path before breaking free and continuing its journey around the sun.
Scientists think 2024 PT5 comes from the Arjuna asteroid group, a collection of near-Earth objects with orbits closely aligned to Earth’s orbit. This group consists of asteroids that have orbits very similar to Earth’s orbit, making them more likely to be temporarily captured by Earth’s gravity. Although 2024 PT5 will leave Earth’s orbit in November, it’s expected to return for another close flyby in January 2025, and possibly again in 2055. These future visits will give scientists additional opportunities to study its trajectory and behavior, improving our understanding of near-Earth objects and how their orbits evolve over time.
As cool as it sounds, this isn’t the first time Earth has temporarily captured an asteroid. In fact, Earth occasionally snags small asteroids that pass nearby, holding them in orbit for a short time before they drift away again. This happened as recently as 2022 with an asteroid named 2022 NX1, which behaved similarly to 2024 PT5. Another well-known example is 2006 RH120, a small asteroid that orbited Earth for about a year between 2006 and 2007 before escaping our planet’s gravity. These temporary satellites offer scientists valuable opportunities to study the gravitational effects between Earth and near-Earth objects, helping us better understand the dynamics of small celestial bodies.
Even though 2024 PT5 is small and won’t be visible to the naked eye, it’s more than just a fun fact for space enthusiasts. Scientists are excited because mini-moons like this might hold valuable minerals or even water, which could be crucial for future space missions. These resources could potentially be harvested to provide fuel or life support for long-term missions. Studying these temporary moons helps advance asteroid mining technologies, which could play a key role in sustaining human exploration beyond Earth.
2024 PT5’s brief capture by Earth’s gravity shows how dynamic and ever-changing our solar system is. Earth doesn’t just have one permanent moon; it occasionally temporarily captures “hitchhikers” like 2024 PT5. These temporary moons offer unique opportunities to study how celestial bodies interact with Earth’s gravity, refine our understanding of near-Earth objects, and potentially unlock secrets about the early solar system. Each of these visitors provides new insights and opens doors for future space exploration, giving us a chance to better understand our cosmic neighborhood.