Overview
- Researchers reported Monday in Nature Astronomy that trans‑Neptunian object 2002 XV93 shows signs of a tenuous atmosphere.
- Telescopes in Japan caught a stellar occultation on January 10, 2024, and the star’s light faded smoothly for about 1.5 seconds, a fingerprint of refraction by gas rather than a bare, airless edge.
- The team estimates a surface pressure of roughly 100 to 200 nanobars, which is 5 to 10 million times thinner than Earth’s air and far below Pluto’s.
- The gas makeup and structure remain unknown, and James Webb Space Telescope data show no surface frosts that would steadily evaporate into an atmosphere.
- Models suggest the atmosphere would vanish within hundreds to about a thousand years without a source, pointing to either recent impact‑released gas or ongoing cryovolcanic venting, while some astronomers urge caution and note a ring could mimic the signal; more occultations and targeted JWST spectroscopy are planned to test persistence, composition, and alternatives.