This trans-Neptunian object beyond Pluto may have an atmosphere that shouldn’t exist

Although astronomers observe and study the universe to solve many mysteries, some celestial objects present in our solar system remain poorly understood. This is the case with this trans-Neptunian object, located beyond Pluto, which may have an atmosphere that shouldn’t exist.

As a reminder, a trans-Neptunian object (TNO) is a celestial body located beyond Neptune’s orbit, in an extremely cold region of the solar system. The most famous is Pluto, which was previously classified as a planet and which also has an atmosphere. 

However, a team of Japanese astronomers, led by Ko Arimatsu of the Ishigakijima Astronomical Observatory, wanted to detect an atmosphere on another trans-Neptunian object, named 2002 XV 93. With a diameter of 500 km, this plutino passed in front of a star on January 10, 2024, allowing scientists to study it. 

They noticed that the star gradually faded, suggesting the presence of a potential atmosphere. Thus, it appears that this TNO has an atmosphere, which is surprising because these celestial objects are very cold and have a very low gravity. In other words, an atmosphere should not exist. 

Regarding 2002 XV 93, observations made with the James Webb Space Telescope show no signs of frozen gases on its surface. As a result, to explain the presence of this potential atmosphere, astronomers believe that an asteroid may have released gases during a collision with this celestial object. However, this is only a theory, and further studies will need to be conducted.