Physicist-Defying Asteroid Spins Itself Into Oblivion — But Doesn't

When reality tears up the textbooks and rewrites the laws of physics

Meet asteroid 2025 MN45: a 700-meter space rock that shouldn't exist. According to every physics textbook ever written, this thing should have torn itself apart long ago. Yet there it spins, completing a full rotation in under two minutes—roughly 70 times faster than the theoretical speed limit for its size.

The discovery, presented at the Lunar and Planetary Science Conference on March 17, has sent astrophysicists scrambling back to their calculators. Objects larger than 150 meters simply cannot spin faster than once every 2.2 hours without centrifugal forces overcoming their own gravity. At higher speeds, they fragment or eject material into space. It's not theory—it's observed physics. Until now.

Dmitrii Vavilov from the University of Washington, who presented the findings, didn't mince words: "The speed of rotation we observed was almost unbelievable. We thought that was crazy that they could rotate any faster."

Key Evidence

• Confirmed rotation period: under 2 minutes (theoretical maximum: 2.2 hours)
• Size: 700+ meters diameter (well above 150m limit)
• Discovery: Vera C. Rubin Observatory, Chile (April-May 2025 observations)
• Publication: The Astrophysical Journal Letters (peer-reviewed)
• Academic presentation: Lunar and Planetary Science Conference, Texas, March 17, 2026

The Rational Explanation

The asteroid must possess genuine structural integrity—solid rock or possibly metal—rather than being a "rubble pile" of loosely bound debris as previously assumed for most asteroids. This would allow it to withstand the extreme rotational forces without disintegrating.

What We Don't Know

Why this asteroid is so fundamentally different from what we thought we knew about asteroid composition. The discovery forces a complete reassessment of how these ancient objects form and evolve. If one asteroid can defy the rules, how many more are out there challenging our understanding of planetary physics?

The Rabbit Hole

This connects to broader questions about early solar system formation. Were asteroids originally much more solid than we believed? Does this explain other anomalous observations? The implications ripple through planetary science—if we're wrong about asteroid structure, what else needs rewriting?