A small, icy rock at the edge of the solar system has its own atmosphere, proving that Pluto isn't as special as we thought.
Space experts used to believe that only large bodies like Pluto had enough gravity to hold onto a thin layer of gas. This discovery found a 100-nanobar atmosphere around 2002 XV93, an object only 250 kilometers wide. It was detected during a stellar occultation, where the rock passed in front of a distant star. This proves that even tiny, frigid worlds in the Kuiper Belt can maintain a gaseous envelope. It completely changes our understanding of how many living atmospheres might exist in the outer reaches of space.
The first detection of an atmosphere on a trans-Neptunian object beyond Pluto
arXiv · 2605.02243
Trans-Neptunian objects (TNOs) in the outer Solar System are predominantly small, icy worlds long presumed to be atmosphereless except for the largest bodies. Until now, Pluto has been unique among TNOs in exhibiting a substantial atmosphere (nitrogen with trace methane and carbon monoxide) at microbar pressure levels. All other known TNOs, including ~ 1000-km-sized bodies such as Eris, Haumea, Makemake, and Quaoar, have shown no detectable atmospheres in stellar occultation observations, with s