Astronomers Detect Atmosphere on Distant Kuiper Belt Object 2002 XV93
Researchers have identified a thin atmosphere around 2002 XV93, a small trans-Neptunian object, marking the first such discovery beyond Pluto.
Astronomers have detected a tenuous atmosphere surrounding (612533) 2002 XV93, a trans-Neptunian object approximately 500 kilometers in diameter, located beyond Pluto in the Kuiper Belt. This marks the first confirmed atmosphere on a celestial body of this size in the outer solar system.
The discovery was made by a team led by Ko Arimatsu of the National Astronomical Observatory of Japan. In January 2024, they observed 2002 XV93 as it passed in front of a distant star, causing a brief dimming of the starlight. The gradual nature of this dimming indicated the presence of an atmosphere.
The atmosphere is estimated to be 50 to 100 times thinner than Pluto's, with a pressure between 100 and 200 nanobars. Its composition likely includes methane, nitrogen, or carbon monoxide.
The origin of this atmosphere remains uncertain. It could result from recent volcanic activity releasing gases from the object's interior or from a cometary impact that deposited volatile materials. Further observations are needed to determine the source and stability of the atmosphere.
This finding challenges previous assumptions that only larger bodies in the Kuiper Belt, like Pluto, could retain atmospheres. It suggests that other small, icy worlds in the outer solar system may also possess transient atmospheres, indicating a more dynamic environment than previously thought.