LA SERENA, Chile — An international team of astrophysicists announced on Thursday, November 12, 2026, the discovery of a distant dwarf planet candidate, 2026 ED138. The frames came from early astronomical sky surveys atop Cerro Pachón in the Chilean Atacama Desert. The object orbits the Sun far beyond Pluto, with an estimated period of 280 years; its steeply inclined trajectory offers insights into gravitational forces that shaped the early solar system.
Research bulletins came from the Smithsonian Institution and NOIRLab. The newly tracked body was resolved in imaging datasets produced by the Vera C. Rubin Observatory’s 3.2-gigapixel optical camera, which can scan the entire southern visible sky every few nights. Rubin’s optical breadth resolved the faint solar reflection from 2026 ED138 across multiple survey epochs. Orbital modeling confirmed its closest approach to the Sun remains well beyond Neptune. Its orbital plane is tilted nearly 30 degrees relative to the primary ecliptic plane, indicating past dynamical scattering by migrating giant gas planets. Historically, deep astronomical surveys focused disproportionately on the northern celestial hemisphere, leaving vast swaths of the southern sky uncharted; the swift detection of 2026 ED138 during initial operations highlights Rubin’s observational speed and depth.
Dr. Megan Schwamb, a planetary scientist at Queen’s University Belfast and a lead researcher on the Rubin solar system operations team, spoke to international science correspondents on Thursday, saying the early candidate discovery demonstrated the extraordinary observational sensitivity of modern large-aperture survey instruments. Observing teams are scheduling follow-up infrared spectroscopy with the European Southern Observatory’s Very Large Telescope and the James Webb Space Telescope to constrain 2026 ED138’s physical diameter and surface albedo. Estimators will check whether the object spans between 500 and 900 kilometers across; that estimate will determine formal classification by the International Astronomical Union.
