Astronomers have identified a fascinating asteroid named 2025 MN45 using early data from the Legacy Space-Time Survey (LSST) Camera, the largest digital camera in the world, at the NSF-DOE Vera C. Rubin Observatory.
Artist’s impression of asteroid 2025 MN45. Image credit: NSF-DOE Vera C. Rubin Observatory / NOIRLab / SLAC / AURA / P. Marenfeld.
Asteroids orbiting the sun rotate at varying speeds, providing critical insights into their formation conditions billions of years ago, as well as their internal structure and evolutionary history.
Fast-spinning asteroids may have been propelled by prior collisions with other space rocks, suggesting they could be remnants of larger parent bodies.
To withstand such rapid spinning, these asteroids must possess enough internal strength to prevent fragmentation, a process where an object breaks apart due to its rotation speed.
Most asteroids consist of aggregates of debris, with their construction limiting how swiftly they can spin without disintegrating based on their density.
In the main asteroid belt, the threshold for stable fast rotation is approximately 2.2 hours. Asteroids exceeding this rotation period must be exceptionally strong to remain intact.
The faster an asteroid spins and the larger it is, the more durable its material must be.
A recent study published in the Astrophysical Journal Letters reveals important insights into asteroid composition and evolution, showcasing how the NSF-DOE Vera C. Rubin Observatory is redefining our understanding of solar system discoveries.
This research presents data on 76 asteroids with verified rotation rates.
It includes 16 ultra-fast rotators with periods ranging from approximately 13 minutes to 2.2 hours, along with three extreme rotators completing a full rotation in under 5 minutes.
All 19 newly identified high-rotation objects exceed the length of an American football field (around 90 meters).
Notably, the fastest-spinning known main-belt asteroid, 2025 MN45, has a diameter of 710 meters and completes a rotation every 1.88 minutes.
This combination establishes it as the fastest rotating asteroid discovered, surpassing 500 meters in diameter.
“Clearly, this asteroid must be composed of exceptionally strong material to maintain its structure at such high rotation speeds,” commented Dr. Sarah Greenstreet, an astronomer at NSF’s NOIRLab and the University of Washington.
“Our calculations suggest it requires cohesive forces comparable to solid rock.”
“This is intriguing because most asteroids are believed to be ‘rubble heap’ structures, composed of numerous small rocks and debris that coalesced through gravitational forces during solar system formation and collisions.”
“Discoveries like this incredibly fast-rotating asteroid result from the observatory’s unmatched ability to deliver high-resolution time-domain astronomical data, thus expanding the limits of what we can observe,” stated Regina Lameika, DOE associate director for high-energy physics.
In addition to 2025 MN45, other significant asteroids researched by the team include 2025 MJ71 (rotation period of 1.9 minutes), 2025 MK41 (rotation period of 3.8 minutes), 2025 MV71 (rotation period of 13 minutes), and 2025 MG56 (rotation period of 16 minutes).
All five of these ultra-fast rotators are several hundred meters in diameter, categorizing them as the fastest-rotating subkilometer asteroids known to date, including several near-Earth objects.
“As this study illustrates, even during its initial commissioning stages, Rubin allows us to investigate populations of relatively small, very fast-rotating main-belt asteroids that were previously unattainable,” Dr. Greenstreet concluded.
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Sarah Greenstreet et al. 2026. Light curve, rotation period, and color of the first asteroid discovered by the Vera C. Rubin Observatory. APJL 996, L33; doi: 10.3847/2041-8213/ae2a30
Source: www.sci.news
