Starting on September 29, 2024, Earth will temporarily gain a new companion in the form of a mini-moon named 2024 PT5. This small asteroid, measuring around 33 meters in length, will be caught in a unique horseshoe orbit around Earth until November 5, after which it will return to its solar orbit. While its temporary status means it won’t make a full revolution around our planet, its close proximity will place it under Earth’s gravitational influence, making it a rare celestial event.
The phenomenon of a mini-moon isn’t entirely new. Earth occasionally captures small asteroids in temporary orbits. These events are often brief and fleeting, lasting anywhere from a few weeks to a couple of months. In fact, 2024 PT5 is part of a group of space rocks called Arjuna asteroids, which have orbits similar to Earth’s, allowing for close approaches. Objects from this group, like 2024 PT5, sometimes get temporarily captured by Earth’s gravity due to their slow speed of around 2,200 miles per hour (3,540 km/h) and their close approach of 2.8 million miles (4.5 million kilometers) from Earth.
What makes 2024 PT5 intriguing is that it might be ejecta from a previous impact on Earth’s moon, though this is still under investigation. Interestingly, despite its close passage, the asteroid won’t be visible to the naked eye, as it is too small and dim. Only powerful telescopes, equipped with specific detectors, will be able to observe it, making this event more of a spectacle for astronomers than for amateur stargazers.
Temporary mini-moons like 2024 PT5 are not unprecedented but are relatively rare. The Earth has previously captured similar objects such as 2006 RH120 and 2020 CD3. The sun’s gravitational pull ultimately ejects these objects, sending them back into solar orbits. Despite its brief stay, 2024 PT5 will make another close pass by Earth on January 9, 2025, and is expected to return in about 30 years.
The discovery of 2024 PT5 highlights the dynamic and ever-changing nature of Earth’s cosmic neighborhood. With more than 35,000 known near-Earth objects, including asteroids, the potential for future temporary moons is likely, and these events are of great interest to the scientific community, especially those involved in planetary defense and asteroid mining.
In the coming decades, space mining could turn asteroids like 2024 PT5 into valuable resources due to their potential to contain precious metals. For now, though, 2024 PT5 is a reminder of the fascinating interactions happening in our solar system and the role Earth plays in occasionally capturing these wandering space rocks. Scientists will continue studying 2024 PT5, and although most of us won’t be able to see it, its presence offers valuable insights into asteroid behavior and near-Earth dynamics.
Image Credit Getty Images JUAN GARTNER
