Planet Earth is bidding farewell to a celestial visitor, asteroid 2024 PT5, which has been following a “mini moon” trajectory for the past two months. The asteroid, measuring about 33 feet (10 meters) in diameter, will break away from Earth’s gravitational influence on Monday, drawn by the stronger pull of the sun.
Although not technically a moon—NASA clarifies it was never fully captured by Earth’s gravity—the asteroid has intrigued scientists.It first came under Earth’s influence in late September, moving in a horseshoe-shaped path. Spotted in August, it currently lies more than 2 million miles (3.5 million kilometers) away, too small and faint to be visible without powerful telescopes.
Astrophysicists Raul and Carlos de la Fuente Marcos of Complutense University of Madrid have closely tracked 2024 PT5, collaborating with Canary Islands telescopes for hundreds of observations. They believe the asteroid might be a lunar boulder ejected by an ancient impact event.
The asteroid will make a brief return in January, zipping past Earth at a safe distance of 1.1 million miles (1.8 million kilometers)—almost five times farther than the moon. By then, it will be traveling more than double its September speed, ensuring it doesn’t linger. NASA plans to use the Goldstone solar system radar antenna in California to study the object in detail during its weeklong visit.
After its close approach in January, 2024 PT5 will continue orbiting the sun, not to return until 2055, when it may once again perform a partial lap around Earth. Scientists are eager to gather more data during its upcoming encounter to better understand this intriguing interloper.