The James Webb Space Telescope has just made a stunning discovery: signs of gas — specifically methane — on the dwarf planet Makemake, one of the most mysterious objects in the Kuiper Belt.

For years, Makemake was thought to be a frozen, inactive relic, orbiting the Sun 45 times farther than Earth, with a diameter of about 1,400 kilometers. But Webb’s data, collected by a team from the Southwest Research Institute, suggest something far more exciting.

Using a technique called solar-induced fluorescence, scientists detected methane above Makemake’s icy surface. That makes it only the second Kuiper Belt object after Pluto to show confirmed traces of gas.

What does this mean? There are two possibilities. First, Makemake could have an extremely thin atmosphere, in equilibrium with its surface ices — similar to Pluto, but even more elusive.
Or second — and even more intriguing — Makemake might be geologically active, releasing methane in powerful bursts, perhaps like geysers. According to models, it could eject hundreds of kilograms of gas per second, rivaling the plumes on Saturn’s moon Enceladus.

Future Webb observations will determine if Makemake’s methane comes from a stable atmosphere or from temporary outgassing events.

Either way, this discovery proves that even in the cold, dark outskirts of our Solar System, worlds we once thought dead may still be surprisingly alive.