Chile's Rubin Observatory spots a possible sixth dwarf planet beyond Pluto that hid in telescope images for a DECADE
Candidate dwarf planet 2026 ED138 orbits roughly 46 times farther from the Sun than Earth and could become only the sixth dwarf planet recognised by the International Astronomical Union.
Matthew Holman, an astrophysicist at Harvard & Smithsonian's Center for Astrophysics, spotted the object on 13 October using search code he co-developed with colleague Kevin Napier to sift billions of detections from Chile's Vera C. Rubin Observatory. Designated 2026 ED138, it sits roughly 46 astronomical units from the Sun — farther out than Pluto — and is estimated to be between 600 and 1,500 kilometres wide. The International Astronomical Union's Minor Planet Center announced it as a candidate this week, though further infrared observations are needed before it can be officially classified.
'Finding an object this big — roughly 1,000 km across — is something that happens maybe once in a generation,' said University of Washington professor Mario Jurić.
ED138 had been hiding in telescope images since 2016 but blended into the crowded Milky Way backdrop until Rubin's new search techniques exposed its movement.
If confirmed, ED138 would become only the sixth officially recognised dwarf planet, joining Pluto, Ceres, Eris, Haumea and Makemake.
