The NSF–DOE Vera C. Rubin Observatory has discovered a large object in the far reaches of the Solar System. Its provisional designation is 2026 ED138, or simply ED138.
The object was found in data collected by the Simonyi Survey Telescope from 4 March to 11 July 2026. The discovery was made by astrophysicist Matthew Holman of the Center for Astrophysics | Harvard & Smithsonian.
ED138 moves in an orbit beyond Pluto. It is currently at a distance of about 46 astronomical units from the Sun, whereas Pluto is at roughly 40.
A preliminary analysis shows that the object's diameter may range from 600 to 1500 kilometres. In terms of brightness and distance, it is among the largest and brightest bodies discovered in this region.
If its status is confirmed, ED138 will join the five dwarf planets recognised by the International Astronomical Union: Pluto, Ceres, Eris, Haumea and Makemake.
The discovery was announced on 27 October 2026 through the IAU Minor Planet Center. It was made even during the preparation phase for the main LSST survey.
Scientists note that additional infrared observations are needed to determine its size precisely. Well, is this only the beginning of the new observatory's work?
Rubin is funded by the US National Science Foundation and the Department of Energy. The object became the first candidate dwarf planet identified by this instrument.
