Astronomers have spotted a massive new dwarf planet candidate hiding in the outer reaches of our solar system, far beyond the orbit of Pluto. Designated 2026 ED138, the large and bright trans-Neptunian object was discovered using the NSF–DOE Vera C. Rubin Observatory in Chile during observations leading up to its Legacy Survey of Space and Time (LSST).
The International Astronomical Union Minor Planet Center officially announced the observations. If confirmed by further analysis, 2026 ED138 would rank among the largest dwarf planets ever discovered in that distant region of the solar system.
Discovery by the Vera C. Rubin Observatory
The potential new dwarf planet was found in observational data gathered between March 4 and July 11, 2026. Matthew Holman, a Rubin Operations team member and in-kind contributor from the Center for Astrophysics | Harvard & Smithsonian, discovered the object while working to improve algorithms designed to search for distant, moving objects.
The discovery marks an early success for the Vera C. Rubin Observatory, which houses the world’s largest digital camera and has just begun its groundbreaking survey of the night sky. Researchers noted that the object had previously eluded detection because of its unique positioning. Orbiting the Sun at roughly 46 times the distance between Earth and the Sun, 2026 ED138 features a tilted orbit inclined at a 25-degree angle from the solar system plane, allowing it to effectively blend into the bright background light of the inner Milky Way.
Characteristics and Orbital Path
As a trans-Neptunian object, 2026 ED138 travels far beyond Neptune, the most distant recognized major planet in our solar system. Astronomers point out that its unusual, tilted orbital pathway strongly suggests the object was disturbed from its original orbit long ago through gravitational interactions with Neptune.
While scientists have classified 2026 ED138 as a dwarf planet candidate, formal confirmation requires additional study of its size, mass, and shape. In astronomical terms, a dwarf planet is a celestial body massive enough to have pulled itself into a round shape under its own gravity, but not large enough to clear away other objects along its orbital path—the same classification given to Pluto by the International Astronomical Union in 2006.
Researchers believe that continued observations from the Vera C. Rubin Observatory could soon reveal many more hidden objects in the distant outskirts of the solar system, shedding new light on its formation and evolutionary history.
