Uranus — our resident sideways, dirty-ringed, fart-smelling seventh planet — shines brighter than it has in nearly 40 years in a startling new image from the James Webb Space Telescope (JWST) released Thursday.
In the photo, Uranus is tilted on its side, making the entire ring system of the planet visible. And because JWST can see in infrared, the normally dull-seeming surface of the oft-ignored planet shows differentiation. There’s a bright cloud on the left part of the planet, which NASA says is connected to storm activity.
The splotchy area on the pole of the planet is a seasonal polar cap that astronomers aren’t entirely sure what its purpose is, but it appears when sunlight strikes Uranus. The planet was last visited in 1986 by the Voyager 2 probe, so understanding the mechanism may require close-up measurements of Uranus.
Uranus is one of two ice giants in our Solar System, the other being Neptune. Like Uranus, Neptune has been visited only once, also by the Voyager 2 probe three years after its encounter with Uranus. Unlike Jupiter and Saturn, the ice giants are lower mass — 14 and 17 Earth masses, respectively — and show an abundance of methane, water, and ammonia.
Methane helps give both planets their blue hues, and all three chemicals exist under extreme pressures that give them a relatively solid form. Because they entered the primordial planets in their ice form, they take on the name “ice giants,” though those chemicals mostly exist as supercritical fluids, where intense pressures cause gases to act like liquids.
There’s some chatter of a return to Uranus, which the National Academy of Sciences gave a high priority to in its last decadal survey, one that should include an atmospheric probe to shed light on some of the mysteries of Uranus. However, no official mission has been greenlit by NASA. This means Uranus will keep some of its secrets from us — for now. But JWST gives us the best possible tools to study it from afar, so this isn’t the last you’ll see of this mysterious, stinky planet.
