UW astronomers spot record-breaking asteroid in Rubin Observatory data
Our take
The recent discovery by a team of astronomers from the University of Washington (UW) of the fastest-ever spinning asteroid, measuring over half a kilometer in diameter, is a thrilling development in the field of planetary science. This record-breaking asteroid, identified using data from the Vera C. Rubin Observatory, highlights the incredible potential of cutting-edge observational technology. The UW team’s findings not only add to our understanding of asteroids but also emphasize the growing importance of the Rubin Observatory as a hub for astronomical discoveries. This follows on the heels of earlier revelations, such as the Early data from Rubin Observatory reveals over 11,000 new asteroids, which showcased the observatory’s ability to unearth vast numbers of celestial bodies in our solar system.
At the heart of this discovery is the sheer speed at which this asteroid spins, prompting questions about its composition, structure, and the forces that govern its behavior. Asteroids are often considered remnants from the early solar system, and understanding their dynamics can provide critical insights into the processes that shaped our planetary neighborhood. The implications of this particular asteroid's rapid rotation could extend beyond mere curiosity; it may influence how we think about asteroid impacts and the potential threats they pose to Earth. Fast-spinning asteroids could have unique physical characteristics that affect their trajectories and collision risks, making this discovery particularly relevant for ongoing discussions about planetary defense.
Moreover, the broader context of this finding cannot be overlooked. As the UW astronomers continue to harness the capabilities of the Rubin Observatory, we are witnessing a paradigm shift in how astronomers gather and analyze data. The observatory’s advanced imaging technique allows for detailed surveys of the night sky, unveiling a wealth of information that was previously inaccessible. As seen in the early data from Rubin Observatory, the ability to detect thousands of new asteroids underscores a rapidly expanding catalog of celestial bodies, potentially reshaping our understanding of the solar system. This growing database offers a treasure trove of opportunities for research, collaboration, and education, inviting students and enthusiasts alike to engage with the wonders of the universe.
Looking ahead, the discovery of this record-breaking asteroid raises critical questions about our role in monitoring these celestial objects. As we continue to explore the cosmos, how do we balance curiosity with the responsibility of keeping our planet safe? Additionally, what other secrets await us in the depths of space as more data becomes available? The ongoing research stemming from the Rubin Observatory will not only satisfy our curiosity but will also be essential in developing strategies to mitigate potential asteroid threats in the future. As technology progresses and our understanding deepens, the possibilities for exploration and discovery seem boundless. The future of astronomy looks bright, and we can only anticipate what other groundbreaking revelations lie ahead in this fascinating field.
UPDATE (January 27, 2026): This story has been updated to highlight the role of the Simonyi Survey Telescope in the research.
A team led by University of Washington astronomers has discovered the fastest-ever spinning asteroid with a diameter over half a kilometer. The asteroid — found while analyzing data from the Simonyi Survey Telescope at the NSF–DOE Vera C. Rubin Observatory — is 0.4 miles in diameter and completes a full rotation every 1.88 minutes.
The study provides crucial information about asteroid composition and evolution. The discovery also demonstrates the potential of the observatory as it prepares for a 10-year nightly survey of the Southern Hemisphere sky, the Legacy Survey of Space and Time (LSST).
The research team published its findings January 7 in Astrophysical Journal Letters.
“It’s really exciting that in some of the very first test images taken with the Vera C. Rubin Observatory that we’re already breaking records with the discovery of the fastest-spinning large asteroid found to date,” said lead author Sarah Greenstreet, a UW affiliate assistant professor of astronomy and astronomer at NSF NOIRLab. “With millions of new asteroids expected to be found by the Rubin Observatory in the near future, this is just the beginning of many exciting discoveries yet to come.”
The study uses data collected over the course of about 10 hours across seven nights in April and May 2025, during Rubin Observatory’s early commissioning phase. That same data revealed thousands of asteroids cruising about our solar system, about 1,900 of which have been confirmed as never-before-seen. Within that flurry, Greenstreet’s team at the UW discovered 19 quickly rotating asteroids, including the record-breaking asteroid dubbed 2025 MN45.
As asteroids orbit the sun, they also rotate at a wide range of speeds. These spin rates not only offer clues about the conditions of their formation billions of years ago, but also tell us about their internal composition and evolution over their lifetimes. In particular, an asteroid spinning quickly may have been sped up by a past collision with another asteroid, suggesting that it could be a fragment of an originally larger object.
Fast rotation also requires an asteroid to have enough internal strength to not fly apart into many smaller pieces, called fragmentation. Most asteroids are “rubble piles,” which means they are made of many smaller pieces of rock held together by gravity, and thus have limits based on their densities as to how fast they can spin without breaking apart.
“Clearly, this asteroid must be made of material that has very high strength in order to keep it in one piece as it spins so rapidly,” Greenstreet said. “We calculate that it would need a cohesive strength similar to that of solid rock, which is quite unusual.”
Most fast rotators discovered so far orbit the sun just beyond Earth, known as near-Earth objects. Scientists find fewer fast-rotating main-belt asteroids, which orbit the sun between Mars and Jupiter, because their greater distance from Earth makes them fainter.
All but one of the newly identified fast-rotators, however, live in the main asteroid belt — an achievement made possible by Rubin’s enormous light-collecting power and precise measurement capabilities.
“As this study demonstrates, even in early commissioning, Rubin is successfully allowing us to study a population of relatively small, very rapidly rotating main-belt asteroids that hadn’t been reachable before,” Greenstreet said.
The discoveries of all 1,900 new asteroids, including the 19 fast rotators, were made possible by software developed by the UW Data-intensive Research in Astrophysics and Cosmology (or DiRAC) Institute. DiRAC’s software will power Rubin’s future solar system discoveries during its 10-year survey.
“These are exciting results but there’s much more to come,” said co-author Mario Jurić, a UW professor of astronomy. “In the next two years, Rubin will discover a thousand times as many asteroids as were presented here. Rubin’s data will open the window into what’s out there in our solar system, and how it all came to be.”
UW co-authors include Zhuofu (Chester) Li, a doctoral student in astronomy and astrobiology; Dmitrii E. Vavilov, a postdoctoral researcher in astronomy; Devanshi Singh, an undergraduate student of physics and astronomy at UW Bothell; Željko Ivezić, a professor of astronomy; Joachim Moeyens, a software engineer in astronomy; Eric C. Bellm, a research associate professor of astronomy; Jacob A. Kurlander, a graduate student of astronomy; Maria T Patterson and Nima Sedaghat, who worked on this study as research scientists in astronomy; Krzysztof Suberlak, a research scientist in astronomy; and Ian S. Sullivan, a senior research scientist in astronomy. A full list of co-authors is included with the paper.
This research was funded by the U.S. National Science Foundation and the U.S. Department of Energy. The DiRAC Institute is supported by the Charles and Lisa Simonyi Fund for Arts and Sciences, Janet and Lloyd Frink and the Washington Research Foundation.
For more information, contact Greenstreet at sarahjg@uw.edu.
This story was adapted from a press release by Vera C. Rubin Observatory.
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