Astronomers using the Vera C. Rubin Observatory in Chile have identified a massive icy object located beyond Pluto, which could potentially claim the title of the Solar System’s sixth official dwarf planet. Provisionally designated as 2026 ED138, the newly discovered body orbits the Sun at a distance of approximately 46 astronomical units, comfortably surpassing Pluto’s average distance of 40 units.
Marking the largest trans-Neptunian discovery in roughly two decades, researchers estimate the object’s diameter ranges between 600 and 1,500 kilometers, putting it on par with Ceres, the smallest currently recognized dwarf planet. Mario Jurić, head of the project’s solar system sector, estimates its size at around 1,000 kilometers, describing the finding as a rare astronomical event.
The celestial body remained hidden for years because its orbit aligns closely with the plane of the Milky Way when viewed from Earth, blending into a dense backdrop of millions of stars. However, the Rubin Observatory’s cutting-edge digital camera—the largest ever built for astronomy—scans the southern sky every few nights, capturing the movement of the object across multiple frames. On October 13, astrophysicist Matthew Holman spotted the anomaly in early-year data using a specialized search algorithm, noting that its extreme brightness for such a distant object immediately caught his attention.
Further investigation through the observatory’s catalog confirmed the object’s presence across 30 separate images spanning 20 nights between March and July, with archival data tracing its orbital path back to 2016. While scientists are optimistic, official classification as a dwarf planet requires further infrared observations to determine its mass, density, and precise shape. If confirmed, it will join a select group of celestial bodies, though formal recognition by the International Astronomical Union may take considerable time.
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