# Rubin Observatory Has Already Found 11,000 Asteroids Before Its Real Survey Starts
META: The Vera C. Rubin Observatory found over 11,000 new asteroids in early test data, including 33 near-Earth objects and a rock that spins in under two minutes. Here is what the numbers actually mean.
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The Vera C. Rubin Observatory in Chile was built to spend ten years repeatedly photographing the entire southern sky. That project, the Legacy Survey of Space and Time, or LSST, has not formally started yet. Even so, the observatory has already submitted detections of more than 11,000 new asteroids to the International Astronomical Union’s Minor Planet Center, and the MPC has confirmed them. It is the largest single batch of asteroid discoveries submitted anywhere in the past year, and it came out of engineering-grade test data.
The numbers behind that headline are worth slowing down for, because they explain why astronomers keep calling this machine transformative rather than merely big.
# Where the 11,000 came from
The discoveries came from roughly one million individual observations taken over about a month and a half during early optimization surveys in mid-2025. Those observations covered the 11,000-plus new asteroids and more than 80,000 already known ones, including some that had been observed decades ago and then effectively lost because their orbits were too uncertain to predict where they would appear next.
The batch adds to earlier Rubin finds: 73 asteroids from initial tests with the smaller Commissioning Camera in late 2024, and 1,514 during the “First Look” observations in April and May 2025 that also produced the first public images from the LSST Camera. Total across every phase so far: about 12,700 asteroids in roughly a year and a half of part-time, commissioning-grade work.
Among the new objects are 33 previously unknown near-Earth asteroids and hundreds of worlds orbiting beyond Neptune, in the transneptunian region.
# Why Rubin finds things other telescopes miss
Most existing asteroid searches work by staring at relatively narrow patches of sky night after night. Rubin does the opposite. Its Simonyi Survey Telescope pairs an 8.4-meter primary mirror with the largest digital camera ever built, a 3,200-megapixel instrument the size of a small car, and sweeps enormous patches of sky per exposure. The observatory can survey the southern sky at roughly six times the sensitivity of most current asteroid searches, which means it picks up smaller and more distant objects than its predecessors could see.
The software side matters just as much. Each night’s images are differenced against reference skies, and candidate moving objects are strung into “tracklets” that must be linked across at least three visits within a 15-night window. The linking software, built around the Heliolinc algorithm, reconstructs heliocentric orbits from those scattered observations. Ari Heinze at the University of Washington, with graduate student Jacob Kurlander, built the discovery pipeline that processed this batch. Rubin’s cadence required a genuinely new software architecture for asteroid discovery, and the 11,000-asteroid haul is the proof it works even on engineering-quality data.
# The two-minute rotators
The First Look sample of 2,103 asteroids produced the first peer-reviewed science from Rubin’s solar system program, published in the Astrophysical Journal Letters. Because Rubin revisits fields so densely, the median asteroid in that sample had 132 individual observations, enough to reconstruct lightcurves, rotation periods and colors for about 2,000 objects.
The standout result was how many small asteroids spin absurdly fast. Of the 76 objects with rock-solid rotation periods, roughly a quarter turn faster than 2.2 hours, which is roughly the limit a loosely-piled rubble asteroid can endure before it flings itself apart. Five of them rotate in under about 15 minutes. One main-belt asteroid, 2025 MN45, completes a rotation in 1.9 minutes, making it the fastest-spinning asteroid larger than half a kilometer that anyone knows of. A loose gravel pile cannot survive that, so these bodies must have real cohesive strength, consistent with solid rock or even the kind of clays found on carbonaceous asteroids.
That finding matters beyond trivia. Sub-kilometer asteroids with fast spins are almost absent from existing catalogs because older surveys lacked the cadence to catch them. Rubin is opening an entire, previously sparse corner of the size-versus-spin-rate map, which feeds directly into models of how asteroids are built and how they break apart.
# What happens when LSST actually begins
Once the decade-long LSST survey starts in earnest, the expectation is that Rubin will match this entire 11,000-asteroid batch every two to three nights during the early years. Over the full survey, scientists project the known asteroid count will roughly triple, and the number of catalogued transneptunian objects should grow nearly tenfold.
For planetary defense the stakes are concrete. Rubin is expected to add close to 90,000 new near-Earth objects, and to push the fraction of known NEOs larger than 140 meters, the size class Congress asked NASA to catalogue, toward around 70 percent. Every one of those is an object that cannot surprise us later.
# The honest caveats
Three things temper the enthusiasm. First, discovery is not characterization: an MPC listing gives an orbit, and often little else. Follow-up needs other telescopes. Second, the flood creates its own workload, because the MPC and the community’s follow-up resources now process in days what they used to process in months. Third, commissioning results always carry some uncertainty; the final LSST cadence was still being tuned as these numbers came out.
Still, the direction is unambiguous. A machine built to watch the sky change has, before its main survey even begins, rewritten the discovery record for a single year. Mario Juric, Rubin’s solar system lead scientist at the University of Washington, called the batch “the tip of the iceberg.” On this evidence, that is not launch-spin.
For more evidence-driven coverage of what trial data and real numbers actually show, see our pieces on [what the statin trials actually demonstrated](https://truza.com/statins-for-primary-prevention-what-the-trials-showed/) and [whether the four-day work week trials held up](https://truza.com/does-the-four-day-work-week-actually-work-what-the-trials-really-showed/). Read more about what we cover on our [about page](https://truza.com/about-us/).