Astronomers have long speculated there are clouds on Pluto, but until the New Horizons probe visited, the theories of Plutonian cover remained just that, theories. Now, according to emails passed between astronomers and spotted by New Scientist, we might have the first concrete evidence that clouds exist on the little planetoid.
In one of those messages, Lowell Observatory astronomer Will Grundy describes “a few bright cloud-like things that seem to be above and cutting across the topography,” as New Scientist reports. If these are indeed clouds, Pluto gets to join several other objects in the solar system with the condensed fluffy stuff: Earth, sulfuric Venus, the gas giants, and Mars — which, as Popular Mechanics reported in February 2015, has mysterious clouds despite its thin atmosphere.
This isn’t the only oddity up in Pluto’s vapor space. Earlier in 2016, NASA revealed that Pluto is encased in a “photochemical smog” of methane that breaks down into tiny hydrocarbons and floats above the planet’s surface. Though this results in a pretty blue haze, it’s not quite the isolated clouds hinted at in the new images. Were Pluto — like fellow dwarf planet Ceres — to in fact have cloud cover, that opens up a new way of looking at these celestial bodies.