Rubin Observatory Discovers Fastest-Spinning Large Asteroid Ever Seen

In early 2026, the Vera C. Rubin Observatory spotted an asteroid breaking an extremely fast spin record. Dubbed 2025 MN45, this roughly 0.4-mile-wide rock in the main asteroid belt spins once every 1.88 minutes, making it the fastest-spinning known asteroid over 500 meters across. At 710 meters wide, MN45 is about the size of eight football fields. This record was found in a survey of nearly 2,000 newly discovered asteroids using Rubin’s powerful new telescope.

Record-breaking Discovery

According to the new study, astronomers found 2025 MN45 in survey data from the Vera Rubin Observatory. It orbits in the main asteroid belt between Mars and Jupiter, and is about 0.4 miles (710 meters) across. This early survey spotted nearly 2,000 new asteroids; 19 of them proved to be “superfast rotators” (spinning in under 2.2 hours). MN45 finishes a full spin in just 113 seconds (1.88 minutes)—far faster than any other asteroid this large.

Clues from the Spin

Such a high spin rate suggests that MN45 is unusually tough. Scientists have calculated that it needs the strength of solid rock to hold together at 113 seconds per rotation. This is surprising because most asteroids of this size are “rubble piles” of loose debris that would break apart much earlier. In general, very rapid spins often hint that an asteroid was blasted off a larger body in a collision. Rubin Observatory will spend the next 10 years surveying the sky with its 3.2-billion-pixel camera, imaging every 40 seconds. It is expected to find thousands of new asteroids during that time.