PARIS: Japanese astronomers announced on Monday that a tiny, little-known world beyond Pluto appears to have an atmosphere, a discovery that challenges what was thought possible for icy objects in our solar system’s distant backyard.

If confirmed, the roughly 500-kilometre-wide (310-mile) rock would become just the second world past Neptune to host an atmosphere. The first is Pluto itself.

Researchers made the discovery by pointing their telescopes at an object named (612533) 2002 XV93, which is nearly 40 times farther from the sun than Earth is.

When the icy world passed in front of a distant star in January 2024, astr­onomers observed that the starlight did not reappear immediately, suggesting a thin atmosphere was filtering some of the light. Acc­ording to a study in Nat­ure Astronomy, they estimate the world has an atmosphere five to 10 million times thinner than Earth’s.

“This is important because, until now, Pluto was the only trans-Neptunian object with a confirmed atmosphere,” said lead study author Ko Arimatsu of the National Astronomical Observatory of Japan.

“This discovery therefore challenges the conventional view that small icy worlds in the outer Solar System are mostly inactive and unchanging.” The finding could also influence the debate over Pluto’s planetary status.

Formerly a planet, Pluto was demoted to a dwarf planet in 2006 as astronomers discovered other similar objects in a distant region called the Kuiper Belt.

While Nasa, under US President Donald Trump, has floated the idea of restoring Pluto’s planet status, the discovery of another atmosphere nearby could undermine the case for its reinstatement.

Published in Dawn, May 5th, 2026