Fastest-spinning asteroid discovered by Rubin Observatory stuns scientists

Six months after starting operations, the Vera C. Rubin Observatory in Chile has released its first set of images. Among the findings is asteroid 2025 MN45, a fast-spinning space rock that completes a full rotation every 113 seconds. The observatory's advanced technology has also uncovered thousands of previously unknown objects in the solar system and beyond.

The observatory, equipped with an 8.4-metre primary mirror and a 3,200-megapixel digital camera—the largest in the world—began scanning the night sky in late 2025. Its initial survey covered around 10 million galaxies, capturing everything from distant nebulae to transient events like supernovae. The data collected will help researchers study dark matter and dark energy in greater detail.

One of the most striking discoveries so far is asteroid 2025 MN45. Measuring about 710 metres across, it is the fastest-spinning asteroid larger than half a kilometre ever observed. Most asteroids in the belt are loose 'rubble piles' that rotate slowly to avoid breaking apart. This one, however, spins at an unusually high rate, suggesting it may be a solid fragment from a past collision.

The asteroid's rapid rotation also points to strong internal cohesion, with a structure more akin to solid rock than a loose collection of debris. Its extreme speed and size make it a rare find in the asteroid belt.

Beyond 2025 MN45, the observatory's first images revealed nearly 2,000 new asteroids, along with objects of varying brightness and detailed views of Milky Way nebulae. The ability to scan vast areas of the sky quickly allows scientists to track fleeting cosmic events with unprecedented precision.

The Vera C. Rubin Observatory's early results highlight its potential to transform astronomy. With its powerful instruments, it will continue mapping the universe, uncovering hidden objects, and providing deeper insights into cosmic phenomena. The discovery of asteroid 2025 MN45 is just one example of how its technology is already expanding our understanding of the solar system.