Space & Astronomy

The atmosphere of Pluto is collapsing as it moves away from the Sun

By T.K. Randall
August 11, 2026

Image: Pluto - New Horizons (2015)
Credit: (PD) NASA Far out in the distant reaches of our solar system, a small, icy world orbits the Sun.

Discovered in 1930, Pluto was originally classed as a full-blown planet until the word was redefined and it was deemed instead to be a dwarf planet back in 2006.

Pluto is on a particularly long orbit - it takes 248 Earth years to go around the Sun, meaning that since its discovery it has yet to even complete half of a single orbit.

Now, new research has found that, as Pluto moves further and further away from the Sun, its atmosphere gets so cold that it literally collapses and condenses into frost on its surface.The observations, which were made by observing Pluto as it passed in front of stars in the sky, indicated that this process may already be starting on this particular orbit.

"We're at a particularly interesting point for Pluto," said lead author Amanda Sickafoose of Arizona's Planetary Science Institute.

"Our work suggests that the atmosphere has recently started decreasing in pressure."

Luckily for Pluto, it is thought that its atmosphere will not be completely frozen by this process, so that when it begins moving back toward the Sun, the frost will sublimate and its atmosphere will thicken.

This cycle has likely been ongoing since the early days of the solar system.

Source: Space.com

Tags: Pluto