Overview
- Researchers led by Japan’s National Astronomical Observatory reported in Nature Astronomy that 2002 XV93 hosts a very thin atmosphere, making it the farthest known body with confirmed air.
- The team used a stellar occultation, in which the object passed in front of a star and its gas envelope bent and dimmed the starlight in a way that marks an atmosphere.
- 2002 XV93 lies beyond Neptune in the trans‑Neptunian region, is estimated to be about 500 kilometers across, and sits around 5.5 billion kilometers from Earth, or roughly 37 times the Earth–Sun distance.
- The result is the first clear detection of an atmosphere on a small outer‑solar‑system body other than planets, Pluto, or large moons, pointing to new ways that cold, low‑gravity worlds can still hold onto volatile gases.
- Scientists say more occultation campaigns and follow‑up observations could pin down what the gas is made of and how stable it is over time, opening a new window on surface–atmosphere processes far from the Sun.