Space & Astronomy

Atmosphere discovered on tiny world beyond the orbit of Neptune

By T.K. Randall
May 5, 2026 ·  0 comments

Image: AI-generated (Midjourney) With a diameter of just 500km across, the unimaginatively titled world (612533) 2002 XV93 has taken astronomers quite by surprise.

Situated in the cold and distant region of the solar system beyond the orbit of Neptune, this small, icy world may have seemed like most other trans-Neptunian objects if it weren't for one critical detail - this one, somehow, has an atmosphere.

Based on what we know about atmospheres, this shouldn't really be possible as this tiny object would seem to be far too small to retain one for any significant length of time.

Thought to be comprised of methane, nitrogen or carbon monoxide, the atmosphere of (612533) 2002 XV93 is admittedly extremely thin - around 5 to 10 million times thinner than that of the Earth.But how could it come to be there? Could something be replenishing it?

One possibility is that this tenuous atmosphere may have been deposited there by a comet impact, while another is that some form of volcanic activity may be creating it.

Whatever might be the case, astronomers have never seen anything quite like it before.

If such a tiny, insignificant piece of ice and rock can maintain an atmosphere, then it opens up the possibility of finding atmospheres in unexpected places throughout the cosmos.

Source: Science Alert | Comments (0)

Tags: Atmosphere, Solar System