Astronomers believe they’ve detected an atmosphere around a tiny, icy world beyond Pluto

Key Points:

• A new study reveals that a small icy world beyond Pluto, known as (612533) 2002 XV93, has a thin atmosphere possibly formed by volcanic activity or a comet impact, marking it as the smallest solar system object with a detected global atmosphere.
• The object, about 300 miles across and located in the Kuiper Belt, has an atmosphere 5 to 10 million times thinner than Earth's and 50 to 100 times thinner than Pluto's, composed likely of methane, nitrogen, or carbon monoxide.
• Observations were made using three Japanese telescopes in 2024 during a stellar occultation event, offering new insights into atmospheres on small bodies far beyond Neptune.
• Experts emphasize the need for independent verification, with future observations by NASA’s Webb Space Telescope expected to clarify the atmosphere’s composition and origin, distinguishing between impact or volcanic sources.
• This discovery challenges the traditional view that atmospheres exist only around large planets, dwarf planets, and some large moons, expanding understanding of small worlds in the outer solar system.