The identification of asteroid 2025 MN45 is a historic milestone in the modern era of space exploration, and it bears out just how much surprise the Universe still has in store for us. Employing the largest digital camera in the world, scientists have found an enormous asteroid that is spinning at an alarming rate, at least for an object so massive, and significantly, it outpaced all expectations for what asteroids like it would be capable of maintaining their shape under. While it certainly breaks numerous records, it actually points to an interesting observation regarding asteroid material, the history of the solar system, and what a new era of telescopes could hold in store for all of us in the lead-up to the decade-long survey that the Vera C. Rubin Observatory will launch.
Asteroid 2025 MN45 sets new spin record in early Rubin Observatory observations
The NSF identified asteroid 2025 MN45–DOE Vera C. Rubin Observatory during its early commissioning phase. The object immediately stood out due to its extraordinary rotation speed, completing one full spin every 1.88 minutes. What makes this particularly significant is its size. While small asteroids are known to rotate rapidly, objects larger than 500 metres were thought to have a natural speed limit. MN45 has shattered that assumption, becoming the fastest-spinning asteroid of its scale ever detected.The discovery was announced during the Rubin Observatory’s First Look event in June 2025 and later detailed in a peer-reviewed study published in The Astrophysical Journal Letters. It was among nearly 1,900 new asteroids detected in a short observational window, highlighting the observatory’s unprecedented surveying power.
How the world’s largest digital camera made it possible
Behind this achievement is the LSST Camera of the Rubin Observatory, the world’s largest digital camera for astronomy. This camera boasts an incredible 3,200 megapixels that are attached to an 8.4-meter mirror system, allowing it to take high-resolution images of the night sky rapidly. For an entire seven nights of its observation period, which occurred from April to May, scientists were able to note the changes of MN45’s brightness, enabling them to compute its rate of rotation.This marks the inaugural peer-reviewed scientific investigation to date that utilizes the data from the LSST Camera, showcasing the ability to achieve high resolution in the time domain, which was not feasible before. As cited, this is a critical function for the detection of objects that would potentially fly under the radar of more legacy architectures.
Asteroid 2025 MN45: Mystery of extreme rotation
Asteroid 2025 MN45 is estimated to be around 710 metres in diameter, yet it spins so quickly that centrifugal forces should tear it apart. Most asteroids of this size are believed to be “rubble piles”, loosely bound collections of rocks and debris held together mainly by gravity. At MN45’s rotation speed, such a structure would simply disintegrate.Instead, scientists believe that this asteroid must have a cohesive strength similar to that of solid rock. This defies conventional models of asteroid formation and implies that some large asteroids may be structurally far stronger than previously believed. The finding opens up new questions about how such objects form, evolve, and endure extreme physical conditions over billions of years.
What fast-spinning asteroids reveal about the solar system
The rotational period of an asteroid can serve as a kind of historical record. Fast-rotating bodies may have been formed by old clashes, gravitational interaction, or breakup from a parent body. Analysing bodies such as 2025 MN45 can provide a valuable window into violent events in our young solar system.
