Mysterious world beyond Pluto may have an atmosphere: astronomers

Key Points:

• Japanese astronomers have detected a possible thin atmosphere around the distant icy object (612533) 2002 XV93, located roughly 6 billion kilometers from the Sun, making it potentially the second known trans-Neptunian object with an atmosphere after Pluto.
• The atmosphere is estimated to be five to 10 million times thinner than Earth's and was inferred from starlight dimming during a stellar occultation observed in January 2024.
• This finding challenges previous assumptions that small icy worlds in the outer Solar System cannot sustain atmospheres and suggests such objects may be more dynamic than thought.
• Alternative explanations, such as the presence of a ring system, have been proposed but are considered less consistent with the observations; further study, especially using the James Webb Space Telescope, is needed to confirm the atmosphere.
• The discovery may impact ongoing debates about Pluto's planetary status, especially amid recent NASA discussions about reinstating Pluto as a planet, though some scientists urge caution and call for more data.