Rubin Observatory Discovers Fastest-Spinning Large Asteroid Ever Seen

Astronomers using the Vera C. Rubin Observatory have discovered asteroid 2025 MN45, the fastest-spinning large asteroid ever recorded. About 710 metres wide, the object completes one full rotation every 1.88 minutes—far quicker than any asteroid of similar size. The finding emerged from an early survey that detected nearly 2,000 new asteroids, including several rare “superfast rotators.” Such an extreme spin implies MN45 is unusually strong, likely composed of solid rock rather than a loose rubble pile. The result offers new insights into asteroid formation and internal structure.