2002 XV93 Shows Atmosphere at 310 Miles Wide, Challenging Kuiper Belt Theory
Updated
Updated · DOGOnews · May 12
2002 XV93 Shows Atmosphere at 310 Miles Wide, Challenging Kuiper Belt Theory
10 articles · Updated · DOGOnews · May 12
A 500-km-wide Kuiper Belt object, 2002 XV93, appears to have an atmosphere—an unexpected finding because bodies that small are usually thought too weak to retain gas.
Stellar occultation data led by Ko Arimatsu's team showed a distant star's light fading gradually, not cutting off sharply, a signature that gas around the object bent and scattered the light.
The result expands a category previously limited in the region to larger worlds such as Pluto and suggests dense global atmospheres may not form only around bigger planetary bodies.
Researchers still do not know the atmosphere's composition or source; proposed explanations include methane or nitrogen released by ice volcanism or by a relatively recent impact.
If an impact created the gas, the atmosphere could be temporary and dissipate within roughly 1,000 years, making 2002 XV93 a rare snapshot of a short-lived outer-solar-system process.
A tiny rock's atmosphere defies known physics. Is it from active ice volcanoes or just a temporary cosmic fluke?
If a tiny ice rock can hold an atmosphere, how many other 'dead' worlds in our solar system are actually active?
2002 XV93: The Smallest Kuiper Belt Object Found With an Atmosphere
Overview
In January 2024, scientists made a groundbreaking discovery by detecting a thin atmosphere around the small Kuiper Belt object 2002 XV93, which is about 500 km wide. This surprising find, made possible through a rare stellar occultation event observed from Japan, challenged the long-held belief that such small bodies in the outer solar system could not retain an atmosphere. By monitoring the gradual fading of a distant star’s light as 2002 XV93 passed in front of it, researchers identified an atmospheric layer, marking the first time an atmosphere was observed on a trans-Neptunian object of this size and opening new paths for understanding distant worlds.