This autumn, Earth will temporarily gain a “mini-moon” as a small asteroid, 2024 PT5, is captured by Earth’s gravity from September 29 to November 25. Discovered by NASA’s ATLAS on August 7, the asteroid hails from the Arjuna asteroid belt and will be too small and dim to see without a professional telescope. Moving at around 2,200 mph, it will not complete a full orbit but will have its path slightly altered before escaping Earth’s gravity. The asteroid is about 32ft long, much smaller than Earth’s moon.