Rubin Observatory Finds Large Dwarf-Planet Candidate

The Vera C. Rubin Observatory has identified 2026 ED138, a bright trans-Neptunian object about 46 astronomical units from the Sun that may be one of the largest dwarf-planet candidates found beyond Neptune. Its estimated diameter is about 600 to 1,500 kilometers; further observations must confirm its size and nearly spherical shape before it could become the sixth officially recognized dwarf planet. The object likely escaped detection because it appears against the crowded Milky Way, while Rubin’s early survey has already found more than 1,000 objects beyond Neptune. ED138’s orbit is tilted nearly 25 degrees from the solar system’s plane, and studying it could offer clues about the solar system’s formation and evolution.