Newly Found Asteroid 2025 MN45 Spins Faster Than Any Known Object Its Size

A newly discovered asteroid, 2025 MN45, is spinning faster than any other of its size, completing a full rotation every 113 seconds. The find comes from the Vera C. Rubin Observatory, which has been scanning the skies for just six months. The observatory, perched 2,647 meters above sea level on Cerro Pachón in Chile, began operations earlier this year. Its 8.4-meter mirror and 3,200-megapixel camera allow it to survey huge areas of the night sky in record time. Within months, it had already detected nearly 2,000 previously unknown asteroids and countless objects with shifting brightness. Asteroid 2025 MN45 stands out among these discoveries. Measuring roughly 710 meters across, it is the fastest-spinning asteroid larger than half a kilometre ever recorded. Most asteroids in the belt rotate slowly to avoid breaking apart, but this one's rapid spin suggests an unusually strong internal structure, akin to solid rock. Researchers believe it may be a fragment of a much larger body. Until now, astronomers had only found around 30–40 asteroids with rotation periods under two minutes. These were typically small, under 200 meters, and identified through lightcurve analysis by projects like Pan-STARRS and the Zwicky Transient Facility. The discovery of 2025 MN45 challenges previous assumptions about how quickly large asteroids can spin without disintegrating. The Vera C. Rubin Observatory's early findings demonstrate its ability to uncover rare and extreme objects in space. With 2025 MN45, scientists now have a unique case to study the limits of asteroid strength and formation. Further observations will help determine whether similar fast-spinning asteroids exist elsewhere in the solar system.