Harvard Astrophysicists Uncover 2026 ED138, a 600-1,500 km Dwarf Planet Candidate
Updated
Updated · GBH News · Oct 27
Harvard Astrophysicists Uncover 2026 ED138, a 600-1,500 km Dwarf Planet Candidate
3 articles · Updated · GBH News · Oct 27
Summary
2026 ED138 was announced Tuesday as a newly spotted outer-solar-system object that researchers say likely ranks among the seven largest bodies found beyond Neptune.
Harvard and Smithsonian scientists said the object escaped detection because it sits against the Milky Way’s bright background, even though it is one of the brightest solar-system finds in decades.
The Vera C. Rubin Observatory in Chile enabled the discovery with its 8-meter mirror and wide field of view, letting astronomers repeatedly scan the visible sky and track moving points of light.
Size remains uncertain because astronomers have measured only its brightness, leaving estimates at 600 to 1,500 kilometers and the dwarf-planet label still provisional pending more imaging.
The find suggests more large Kuiper Belt objects may still be hidden in crowded or distant parts of the sky, despite decades of searches.