Astronomers discover a possible new dwarf planet in Solar System
The Vera Rubin Observatory has detected a possible new dwarf planet orbiting the Sun beyond Neptune, marking a potentially significant discovery in the outer Solar System, Qazinform News Agency reports, citing Space.com.
The icy object, designated as 2026 ED138, is estimated to measure between 600 and 1,500 kilometers in diameter. According to scientists, it may be large enough for its own gravity to be sculpted into a nearly spherical body, one of the key criteria for classifying an object as a dwarf planet.
If confirmed, 2026 ED138 would join the five officially recognized dwarf planets in the Solar System: Pluto, Ceres, Eris, Haumea and Makemake.
The object was discovered by Matthew Holman of the Center for Astrophysics | Harvard & Smithsonian (CfA). On October 13, he identified it while analyzing previously collected data from the Vera Rubin Observatory using a search code developed with his CfA colleague Kevin Napier.
The search revealed an object beyond Neptune’s orbit that appeared unusually bright despite its great distance from the Sun. This suggested that it could be larger than the average trans-Neptunian object.
“My first reaction was one of excited disbelief,” Holman said in a statement released on October 27, when the discovery was announced. "Objects like this are very rare, so I immediately started checking whether I or the code had done something wrong."
Located atop Cerro Pachón in northern Chile at an altitude of 2,682 meters, the Vera Rubin Observatory is equipped with an 8.4-meter primary mirror. The observatory achieved first light in April 2025 and began its main scientific program, the 10-year Legacy Survey of Space and Time (LSST), in June 2026.
Earlier, it was reported that samples returned from the Moon’s far side suggest that uneven heating caused by Earth’s gravity helped shape its contrasting hemispheres billions of years ago.
