A World Beyond Neptune Has An Atmosphere And Scientists Don’t Know Why

InnovationScienceA World Beyond Neptune Has An Atmosphere And Scientists Don’t Know WhyByJamie Carter,Senior Contributor.Forbes contributors publish independent expert analyses and insights. An award-winning reporter writing about stargazing and the night sky.Follow AuthorMay 14, 2026, 02:15am EDT--:-- / --:--This voice experience is generated by AI. Learn more.This voice experience is generated by AI. Learn more.Artist’s conception of this research showing an imagined time sequence as a star passes behind a TNO with an atmosphere.NAOJBeyond Neptune is the Kuiper Belt, a doughnut-shaped region icy bodies and dwarf planets often called Trans-Neptunian Objects. Most famously, there’s Pluto, but also Eris, Haumea, Makemake, Gonggong and Arrokoth. About 80 have been found, with potentially thousands more, but humanity’s ever more powerful telescopes and techniques.Another has just been found and, impossibly, it appears to have an atmosphere. Called 2002 XV93, this small object in the far reaches of the solar system may possess a thin atmosphere, despite being far too small to sustain one according to current scientific theories.Too Small For An AtmosphereScientists have long believed that only the largest TNOs, such as Pluto, could maintain atmospheres due to their stronger gravity and volatile-rich surfaces. Pluto’s thin, tenuous atmosphere of nitrogen, methane and carbon monoxide is around 100,000 times less dense than Earth’s.About 310 miles (500 kilometers) in diameter, 2002 XV93 is much smaller than Pluto, which measures about 1,473 miles (2,370 kilometers) across. Its weak gravity and frigid environment should make it nearly impossible for gases to remain trapped around the object for long periods.MORE FOR YOUA Lucky Celestial AlignmentThe discovery was made possible by a rare astronomical event known as a stellar occultation. On Jan. 10, 2024, 2002 XV93 passed directly in front of a distant star as viewed from Japan, where a research team from the National Astron...