Astronomers have found an atmosphere on a tiny world beyond Neptune, 2002 XV, which measures around 500 kilometers (310 miles) across and is too small for its weak gravity to retain an atmosphere for long. This discovery may change our understanding of atmospheric retention. The object, which shares an orbit similar to Pluto's, is found to be in resonance with Neptune's orbit. The researchers used advanced techniques to observe this event, a stellar occultation, from 2024. They observed the event from three locations in Japan, recording the star's light briefly disappearing as 2002 XV passed in front of a distant star. The team's refraction models suggested an atmosphere of just 100 to 200 nanobars, around 5 to 10 million times thinner than the atmospheric density of Earth at sea level. The discovery suggests that even small planets, like Pluto, can host atmospheres, suggesting that even smaller bodies can also host such atmospheres.