Vera C. Rubin Observatory discovers ultra-fast rotating asteroid

Astronomers using data from the Vera C. Rubin Observatory have identified a large asteroid, cataloged as 2025 MN45, that rotates at a speed defying current structural models. Located in the main asteroid belt between Mars and Jupiter, the object is estimated to be approximately 710 meters in diameter and completes a full rotation in roughly 1.88 to 4 minutes.

According to established scientific theories, asteroids of this size should fragment if their rotation period falls below approximately 2.2 hours, as they are typically viewed as loosely bound ‘rubble piles’ held together by weak gravity. However, 2025 MN45 shows no signs of disintegration, suggesting it possesses much higher internal cohesion or a denser composition than previously expected.

The research, involving a team led by Dmitrii Vavilov and including researchers like Sarah Greenstreet, analyzed a subset of data from a massive census of the sky. Out of the asteroids examined, 19 were found to have rotation periods below the theoretical safety limit, indicating that high-density asteroid populations may be more common than current models suggest.