Free Astronomy Magazine July-August 2026

50 JULY-AUGUST 2026 ASTRO PUBLISHING damage if they impact, yet scientists estimate that only about 40% of these mid-sized NEOs have been identified so far. Once operating fully in survey mode, Rubin is expected to reveal an additional nearly 90,000 new NEOs, some of which may be poten- tially hazardous, and to nearly double the num- ber of known NEOs larger than 140 meters to around 70%. By en- abling early detection and continuous moni- toring of these objects, Rubin will be a power- ful tool for planetary defense. The dataset also contains roughly 380 trans-Neptunian objects (TNOs) — icy bodies orbiting beyond Nep- tune. Two of the newly discovered TNOs — provisionally named 2025 LS 2 and 2025 MX 348 — have been found to be on extremely large and elongated, or stretched out, 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 minor planets known. The discoveries were enabled by Rubin Observatory’s unique combi- nation of a large mirror, the world’s most powerful astronomical digital camera, and highly sophisticated, software-driven pipelines designed to detect faint, fast-moving objects against a crowded sky. Rubin can survey the southern sky at roughly six times the sensitivity of most cur- rent asteroid searches, allowing it to detect smaller and more distant ob- jects than ever before. These capa- bilities will allow Rubin to build the most detailed census of our Solar ing 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 i- dentify those that are likely to be distant worlds in our Solar System required novel algorithmic approach- es,” says Matthew Holman, a Senior As- trophysicist at the Center for Astro- physics | Harvard & Smithsonian and for- mer Director of the Minor Planet Center, who spearheaded the work on the TNO dis- covery 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 undis- covered 9 th large planet may still be out there,” says Kevin Napier, a re- search scientist at the Harvard- Smithsonian Center for Astrophysics who, with Holman, developed the algorithms to detect distant Solar System objects with Rubin data. The MPC’s verification of this large group of discoveries enables the en- tire global community to access the data, refine orbits, and begin analy- sis immediately. And these ~11,000 asteroids are just the start. Once the decade-long Legacy Survey of Space and Time (LSST) begins later this year, scientists expect Rubin to dis- cover this many asteroids every two to three nights during the early years of the survey. This will ulti- mately triple the number of known asteroids and increase the number of known TNOs by nearly an order of magnitude. https://noirlab.edu/public/videos/noirlab2608a/ T his animation shows the inner Solar System populated with known asteroids in dark blue and asteroids discovered by Rubin in light teal. [NSF–DOE Vera C. Rubin Observatory/NOIRLab/SLAC/AURA/R. Proctor. Star map: NASA/Goddard Space Flight Center Scientific Visu- alization Studio. Gaia DR2: ESA/Gaia/DPAC. Image Processing: M. Za- mani (NSF NOIRLab)] System ever, and all of the discover- ies will help scientists work out the story of the Solar System’s history. “Rubin’s unique observing cadence required a whole new software ar- chitecture for asteroid discovery,” says Ari Heinze, University of Wash- ington, who, together with Jacob Kurlander, a graduate student at the University of Washington, built the software that detected them. “We built it, and it works. Even with just early, engineering-quality data, Rubin discovered 11,000 asteroids and measured more precise orbits for tens of thousands more. It seems pretty clear this observatory will rev- olutionize our knowledge of the as- teroid belt.” Particularly striking is the rapid growth of the TNO population. The 380 candidates discovered by Rubin in less than two months add to the 5,000 discovered over the past three decades. As with less distant aster- oids, finding the TNOs depended critically on developing new sophis- ticated algorithms. “Searching for a TNO is like search- !