Overview
- The Nature Astronomy paper published Monday reports a thin, global atmosphere around (612533) 2002 XV93 based on a January 2024 stellar occultation observed at three sites in Japan, where starlight dimmed gradually for about 1.5 seconds near the edge of the shadow.
- The team estimates a surface pressure of roughly 100 to 200 nanobars, about 5 to 10 million times thinner than Earth’s air and around 50 to 100 times thinner than Pluto’s.
- The object is about 500 kilometers across, follows a Pluto-like orbital rhythm known as a plutino, and was more than 3.4 billion miles from the Sun during the observations.
- Researchers outline two leading origins for the gas, either a recent impact that released volatiles or ongoing cryovolcanic outgassing, with fading over years versus persistence helping to tell the difference.
- Planetary scientists urge independent checks using repeat occultations and spectroscopy with the James Webb Space Telescope, and some note alternatives such as a near-edge-on ring remain possible.