Using preliminary data from the Simonyi Survey Telescope at the NSF–DOE Vera C. Rubin Observatory, scientists have discovered over 11,000 new asteroids in our solar system. The findings were confirmed by the International Astronomical Union’s Minor Planet Center (MPC), and include hundreds of distant worlds beyond Neptune as well as 33 previously unknown near-Earth objects.
The discoveries — Rubin Observatory’s largest asteroid haul yet — were made using data from the observatory’s early optimization surveys and processed with software developed at the University of Washington’s Data-Intensive Research in Astrophysics and Cosmology (DiRAC) Institute. The new findings are a powerful preview of the observatory’s transformative impact on solar system science.
“This first large submission after Rubin First Look is just the tip of the iceberg and shows that the observatory is ready,” said Mario Jurić, a UW professor of astronomy and leader of Rubin’s solar system team, which is located at the UW. “What used to take years or decades to discover, Rubin will unearth in months. We are beginning to deliver on Rubin’s promise to fundamentally reshape our inventory of the solar system and open the door to discoveries we haven’t yet imagined.”
The submission to MPC comprises approximately 1 million observations, taken over the span of a month and a half, of over 11,000 new asteroids and more than 80,000 already known asteroids, including some that had previously been observed but were later “lost” because their orbits were too uncertain to predict their future locations. The new batch adds to roughly 1,500 asteroids previously discovered by Rubin as part of its First Look project.
The newly discovered near-Earth objects, or NEOs, are small asteroids and comets whose closest approach to the sun is less than 1.3 times the distance between Earth and the sun. None of the new NEOs pose a threat to Earth. Once in full operation, Rubin is expected to reveal an additional nearly 90,000 new NEOs, some of which may be potentially hazardous. By enabling early detection and continuous monitoring of these objects, Rubin will be a powerful tool for planetary defense.
The dataset also contains roughly 380 trans-Neptunian objects (TNOs) — icy bodies orbiting beyond Neptune. Two of the newly discovered TNOs — provisionally named 2025 LS2 and 2025 MX348 — have been found to be on extremely large and elongated orbits. At their most distant points, these two objects reach roughly 1,000 times farther away from the sun than the Earth is, placing them among the 30 most distant known asteroids.
A total of 12,700 asteroids discovered with Rubin are shown here during the 1.6 years of observation. The discoveries come in three bursts: 73 were discovered during the first early test observations using Rubin’s Commissioning Camera in late 2024; 1,514 were discovered during First Look observations in April and May 2025; and the recent 11,000 asteroids were discovered in Rubin’s early optimization surveys in Summer 2025.
The discoveries were enabled by Rubin Observatory’s unique combination of a large mirror, the world’s most powerful astronomical digital camera, and highly sophisticated, software-driven pipelines developed at the UW that can detect faint, fast-moving objects against a crowded sky. These capabilities will allow Rubin to build the most detailed census of our solar system ever, and the resulting discoveries will help scientists work out the story of the solar system’s history.
“Rubin’s unique observing cadence required a whole new software architecture for asteroid discovery,” said Ari Heinze, a UW research scientist of astronomy who, together with UW astronomy graduate student Jacob Kurlander, built the software that detected them. “We built it, and it works. It seems pretty clear this observatory will revolutionize our knowledge of the asteroid belt.”
Particularly striking is the rapid growth of the TNO population. The 380 candidates discovered by Rubin in less than two months adds to the 5,000 discovered over the past three decades. As with less distant asteroids, finding the TNOs depended critically on developing new sophisticated algorithms.
“Searching for a TNO is like searching for a needle in a field of haystacks — out of millions of flickering sources in the sky, teaching a computer to sift through billions of combinations and identify those that are likely to be distant worlds in our solar system required novel algorithmic approaches,” said Matthew Holman, a senior astrophysicist at the Harvard & Smithsonian Center for Astrophysics and former director of the Minor Planet Center, who spearheaded the work on the TNO discovery pipeline.
“Objects like these offer a tantalizing probe of the solar system’s outermost reaches, from telling us how the planets moved early on in the solar system’s history, to whether a hitherto undiscovered ninth large planet may still be out there,” said Kevin Napier, a research scientist at the Harvard-Smithsonian Center for Astrophysics who, with Holman, developed the algorithms to detect distant solar system objects with Rubin data.
The verification of this large group of discoveries enables the entire global community to access the data, refine orbits and begin analysis immediately. And these 11,000-some asteroids are just the start. Once the decade-long Legacy Survey of Space and Time (LSST) begins later this year, scientists expect Rubin to discover this many asteroids every two to three nights during the early years of the survey. This will ultimately triple the number of known asteroids and increase the number of known TNOs by nearly an order of magnitude.
Rubin Observatory is jointly operated by NSF NOIRLab and SLAC.
For more information, contact Jurić at mjuric@uw.edu.
This story was adapted from a press release by NOIRLab.
Operations of the Vera C. Rubin Observatory are funded by the U.S. National Science Foundation and the U.S. Department of Energy’s Office of Science.
Other team members include Pedro Bernardinelli, a former DiRAC postdoctoral fellow at the UW, now at the Institute for Astronomy, Geophysics and Atmospheric Sciences of the University of São Paulo; Joachim Moeyens, a UW research software engineer and B612 Asteroid Institute team member who earned his doctorate in astronomy at the UW; Siegfried Eggl, a former UW postdoctoral researcher in astronomy, now at the University of Illinois Urbana-Champagne; and Erfan Nourbakhsh at Princeton University.