Imagine an asteroid the size of eight football fields spinning so fast it completes a full rotation every two minutes. Sounds like science fiction, right? But it’s real, and it’s just one of the mind-boggling discoveries made by the NSF–DOE Vera C. Rubin Observatory during its pre-survey observations. This groundbreaking find, detailed in the first peer-reviewed paper using data from the LSST Camera, isn’t just a record-breaker—it’s a window into the mysterious world of asteroid composition and evolution. And this is the part most people miss: it’s also a testament to how Rubin is revolutionizing our ability to explore the Solar System.
Published on January 7, 2026, the study reveals that Rubin has already observed thousands of asteroids, with about 1,900 being entirely new discoveries. Among these, 19 are super- and ultra-fast rotators, including the fastest-spinning asteroid larger than 500 meters ever recorded. Led by Sarah Greenstreet, an NSF NOIRLab assistant astronomer, the research team presented their findings in The Astrophysical Journal Letters and at the 247th meeting of the American Astronomical Society in Phoenix, Arizona.
But here’s where it gets controversial: How can an asteroid spin so fast without breaking apart? Most asteroids are ‘rubble piles’—loose collections of rock held together by gravity. Yet, this newly discovered asteroid, named 2025 MN45, must be made of material with the strength of solid rock to withstand such rapid rotation. This challenges our understanding of asteroid structures and raises questions about their formation and history.
The Rubin Observatory, a joint program of NSF NOIRLab and the DOE’s SLAC National Accelerator Laboratory, is equipped with the world’s largest digital camera. Its Legacy Survey of Space and Time (LSST) will scan the Southern Hemisphere night sky for ten years, creating an unprecedented time-lapse record of the Universe. Luca Rizzi, an NSF program director, aptly notes, ‘Rubin will find things that no one even knew to look for.’
The LSST Camera’s data, collected during Rubin’s early commissioning phase in April/May 2025, has already proven invaluable. Regina Rameika, DOE Associate Director for High Energy Physics, emphasizes, ‘Discoveries like this are a direct result of the observatory’s unique capability to provide high-resolution, time-domain data.’
Aaron Roodman, Deputy Head of LSST, highlights Rubin’s speed and efficiency: ‘Together, Rubin can take an image every 40 seconds.’ This rapid imaging has allowed astronomers to identify thousands of new asteroids in a short period, offering a glimpse of what the full 10-year survey will uncover.
Asteroids spin at various speeds, which provide clues about their formation, internal composition, and evolutionary history. Fast rotation often suggests a past collision, implying the asteroid could be a fragment of a larger object. However, to spin rapidly without fragmenting, an asteroid must have significant internal strength—a trait rarely seen in rubble-pile asteroids.
The study identifies 76 asteroids with reliable rotation periods, including 16 super-fast rotators and three ultra-fast rotators. All 19 newly identified fast-rotators are larger than an American football field, with 2025 MN45 completing a rotation every 1.88 minutes. This makes it the fastest-spinning asteroid of its size ever found.
Greenstreet explains, ‘This asteroid must be made of material with very high strength to remain intact.’ Its cohesive strength is comparable to solid rock, which is surprising given that most asteroids are rubble piles. This discovery challenges conventional wisdom and invites further exploration.
Interestingly, most fast-rotating asteroids are near-Earth objects (NEOs), but Rubin has found these rapid spinners in the main asteroid belt—a region where they’re harder to detect due to greater distance. This achievement is a testament to Rubin’s light-collecting power and precision.
Other notable discoveries include asteroids 2025 MJ71, 2025 MK41, 2025 MV71, and 2025 MG56, all of which spin at astonishing speeds. These findings expand our understanding of fast-rotating asteroids and their properties.
As Rubin begins its 10-year LSST survey, scientists expect to uncover even more fast rotators. Unlike the dense, rapid observations of the First Look event, LSST’s regular scans will gradually reveal these objects, providing critical insights into their strengths, compositions, and collision histories.
Thought-provoking question: If these fast-spinning asteroids are stronger than we thought, could they be remnants of a larger, more cohesive body that broke apart billions of years ago? Share your thoughts in the comments—let’s spark a discussion!
For more details, read the full paper, ‘Lightcurves, rotation periods, and colors for Vera C. Rubin Observatory’s first asteroid discoveries,’ in The Astrophysical Journal Letters. And stay tuned as Rubin continues to push the boundaries of what we know about our Universe.
