Detection of an atmosphere on a trans-Neptunian object beyond Pluto
5 hours ago
- #Astronomy
- #Trans-Neptunian Objects
- #Atmospheres
- Pluto is currently the only trans-Neptunian object (TNO) with a detected atmosphere, with a surface pressure around 10 μbar.
- A stellar occultation campaign on January 10, 2024, detected a refractive signature indicating a thin atmosphere around the TNO (612533) 2002 XV93, which has a radius of about 250 km.
- The derived surface pressure for 2002 XV93 is 100–200 nbar, exceeding previous upper limits for other larger TNOs.
- This discovery suggests that even relatively small TNOs (a few hundred kilometers in size) can host at least transient atmospheres, challenging existing volatile-retention models.
- Possible mechanisms for such atmospheres include ongoing cryovolcanic activity or recent impacts by small icy objects.