A newly discovered asteroid, designated 2025 MN45, is shattering previous records for rotational speed. The space rock completes a full spin in just 112 seconds – faster than any asteroid of its size previously observed. This discovery, made possible by the Vera C. Rubin Observatory in Chile, provides critical new insights into asteroid composition and the early history of our solar system.
Unprecedented Rotational Velocity
The asteroid’s rapid rotation period is remarkable. Previous record holders rotated in approximately 30 minutes to an hour. 2025 MN45 spins more than 30 times faster than these, making it a standout among known asteroids wider than 500 meters. Astronomers believe its structural integrity depends on being solid rock, otherwise, it would disintegrate under such extreme centrifugal forces.
The Vera C. Rubin Observatory’s Role
This breakthrough is largely attributed to the Rubin Observatory, which systematically images the entire southern sky every few nights over a 10-year period. This unprecedented observation capability allowed scientists to identify and measure the rotational periods of thousands of previously unseen asteroids. The initial dataset released in June contained over 2,100 solar system objects, with 90% being entirely new discoveries.
Why Rotation Speed Matters
Measuring asteroid rotation isn’t just about speed; it reveals crucial information about their internal structure. Faster rotation implies greater structural cohesion. Most large asteroids are loosely bound “rubble piles” that would break apart if spun too quickly. The fact that 2025 MN45 and others like it can maintain integrity at high speeds suggests they’re made of dense, solid material, such as rock or clay.
Implications for Solar System History
Sixteen of the asteroids discovered by Rubin exhibit unexpectedly high rotation rates, including three that rotate faster than once every five minutes. This suggests a potentially large population of such “speedy spinners” exists within the asteroid belt between Mars and Jupiter. These asteroids may be fragments of larger parent bodies shattered in ancient collisions, preserving pristine material from the early solar system.
“Rotation speeds are one of the only ways we can learn about the internal strengths, compositions and collisional histories of asteroids,” explains astronomer Sarah Greenstreet, highlighting the value of this research.
Ultimately, understanding the diversity of asteroids like 2025 MN45 will help astronomers reconstruct the chaotic events that shaped our solar system billions of years ago. The Rubin Observatory’s continued observations will undoubtedly uncover more of these fascinating objects, deepening our understanding of the celestial bodies that orbit our sun.
