Scientists Identify New Dwarf Planet Candidate Beyond Pluto Using Chilean Observatory

Scientists utilizing a telescope in Chile have identified an icy object orbiting beyond Pluto that may join the solar system's small roster of dwarf planets. The candidate, designated 2026 ED138, has an estimated diameter ranging between roughly 370 and 930 miles, or 600 to 1,500 kilometers.

The object orbits about 46 times farther from the sun than Earth. By comparison, Pluto orbits at an average distance of approximately 40 times Earth's distance from the sun. The discovery was spotted using the new Vera C. Rubin Observatory, located on the summit of Cerro Pachón mountain in central Chile. The telescope operates as a joint initiative of the US National Science Foundation and the US Department of Energy.

Further observations are required to confirm the classification of 2026 ED138 as a dwarf planet. If confirmed, it would join five other dwarf planets recognized by the International Astronomical Union, which serves as the global authority on classifying celestial bodies. The currently recognized dwarf planets are Pluto, Eris, Haumea, and Makemake—all located beyond Neptune—alongside Ceres, which is situated in the main asteroid belt between Mars and Jupiter. Based on current data, 2026 ED138 would rank among the largest of these bodies.

Astrophysicist Matt Holman of the Center for Astrophysics, Harvard & Smithsonian, who first spotted the object, noted that the finding highlights the potential for future discoveries with the Rubin Observatory and other telescopes. The discovery itself was announced during a scientific meeting held in Spokane, Washington.

To officially qualify as a dwarf planet, an object must possess sufficient mass for its own gravity to pull it into a round shape. While 2026 ED138 appears to meet this mass requirement, scientists still have questions regarding its precise size and composition. Establishing the physical size remains the primary next step.

Because observations with the Rubin Observatory measure sunlight reflected off the object, distinguishing between a smaller, highly reflective object and a larger, less reflective one requires additional data. Researchers plan to utilize longer wavelengths with observatories such as the Atacama Large Millimeter/submillimeter Array (ALMA), another powerful telescope based in Chile, to detect the light emitted directly by the object and accurately measure its dimensions.

"This discovery highlights the continuous advancement of scientific instrumentation and observational infrastructure, such as the Vera C. Rubin Observatory. In high-technology and capital-intensive sectors, cutting-edge infrastructure often serves as the foundational catalyst for new data, research breakthroughs, and future technological applications. While this development is purely scientific rather than commercial, it underscores the broader impact of sustained investment in advanced research tools." — Dr. Shishir Gupta, Founder & CEO, StartupLanes