Astronomers may have found a new member of our solar system's dwarf planet family. The distant, icy object, provisionally designated 2026 ED138, was discovered in data from the Vera C.
Rubin Observatory in Chile, and if confirmed, it would join Pluto, Ceres, Eris, Haumea, and Makemake as the sixth recognized dwarf planet. The object is thought to be anywhere between 600 and 1,500 kilometers (370 and 930 miles) in size and may turn out to be one of the biggest TNOs discovered in the last two decades and probably bigger than the smallest known dwarf planet called Ceres.
The TNO orbits the Sun at around 46 AU, which is further away from the Sun than Pluto's average of 40 AU. The senior astrophysicist at the Harvard & Smithsonian Center for Astrophysics, Matthew Holman, detected the object while going through the Rubin survey data with the help of his code.
"My first reaction was one of excited disbelief," said Matthew. Matthew's colleague at the University of Washington, Mario Jurić, located 20 more observations made since March 2026, and the archived data helped to map the orbit of the object for more than ten years.
This TNO remained undetected because it is located in the southern hemisphere, which was not well covered in previous surveys, and the location of the TNO is close to the galactic plane where millions of stars obscure moving objects. Confirmation is not yet assured.
To qualify as a dwarf planet, an object must be massive enough for gravity to pull it into a round shape. Scientists are continuing their detailed observations to verify its physical properties and exact orbital characteristics.
The discovery marks a significant milestone in modern astronomy, highlighting the power of advanced telescopes and machine learning algorithms in scanning massive survey datasets. The Vera C.
Rubin Observatory continues to revolutionize our understanding of the outer solar system. As research progresses, the scientific community anticipates more revelations from the southern skies.
The ongoing surveys are expected to uncover numerous other distant bodies, shedding light on the formation and evolution of our cosmic neighborhood. Further spectroscopic analysis will be required to determine the surface composition of 2026 ED138.
Researchers believe that studying such primordial objects can provide vital clues about the early history of the planetary system. Ultimately, whether it achieves official dwarf planet status or remains a prominent trans-Neptunian object, this discovery opens exciting new avenues for planetary science and deep space exploration in the coming decades.