Astronomers have identified a massive icy body orbiting in the distant Kuiper Belt beyond Neptune, potentially adding a sixth recognized dwarf planet to the solar system.
The distant candidate was found after astronomers analyzed automated observation data gathered by the Rubin Observatory in Chile. Originally captured across multiple years by dark energy monitoring equipment in 2017, 2018, 2019, and 2023 without drawing distinct attention, the object’s presence was unmasked when researchers applied advanced computational tools to sweep through billions of moving cosmic targets.
Matthew Holman, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics who first spotted the object, initially experienced mixed excitement and disbelief and quickly ran verification checks to rule out software glitches according to reporting from the region. Working alongside Mario Juric, Holman traced archival records to reconstruct more than a decade of the object’s orbital trajectory.
Orbital Metrics and Location in the Kuiper Belt
The newly detected candidate orbits in the distant Kuiper Belt, a vast ring-shaped zone filled with icy debris situated past Neptune according to international scientific coverage. Positioned at a distance of roughly 46 astronomical units from the sun—where one astronomical unit equals the average distance between Earth and the sun—2026 ED138 travels even further out than Pluto, which orbits at approximately 40 astronomical units as detailed in technical summaries.
Completing a single trip around the sun takes the object roughly 281 years as calculated in early institutional models. Its orbital plane is tilted by approximately 24.5 degrees relative to the main plane of the solar system, keeping it positioned within the southern sky where observing conditions present unique obstacles.
IAU Must Confirm Dwarf Planet Status
Formal classification as a dwarf planet requires confirmation by the International Astronomical Union, the global authority on celestial taxonomy noted in official program briefs. The organization currently recognizes only five dwarf planets: Ceres, Pluto, Haumea, Makemake, and Eris.
To qualify under criteria established after Pluto was reclassified in 2006, a body must orbit the sun, possess sufficient mass for its own gravity to pull it into a roughly spherical shape, and clear its orbital neighborhood of competing debris explained through professional astronomical definitions.
Matt Holman said via Bdnews24 that This discovery proves that many more exciting discoveries await us through the Rubin Observatory and other telescopes.
Because reflected sunlight can make small, highly reflective icy bodies look just as bright as massive, dark ones, calculating exact sizes remains challenging according to participating scientists.
It is possible to observe the inherent light emitted by the object at long wavelengths using powerful radio telescopes such as the Atacama Large Millimeter/submillimeter Array or ALMA located in Chile, which will play a major role in measuring its exact size. Matt
Prospects for Future Discoveries at the Solar System Boundary
The discovery was formally announced during a scientific conference hosted by the American Astronomical Society's Division for Planetary Sciences in Spokane, Washington reported by conference attendees.
Megan Schwamb, an astrophysicist, expressed surprise at finding such a large object so early in the telescope’s operational timeline noted in correspondence. Independent researchers similarly emphasized that the detection proves the capabilities of modern astronomical infrastructure.
This is fantastic! I am very happy. It is truly a joy to get proof that this massive, expensive, and complex machine is working properly. According
Scientists project that the observatory could locate numerous new trans-Neptunian objects over the coming decade according to astronomical projections, opening a deeper understanding of the primordial ice worlds populating the outer edges of our solar system.