In 1986, in a flyby shooting, the Voyager 2 space probe took some of our first photos of Uranus. The planet looked blue-green and featureless, a planetary pokerface. In the decades since, we’ve learned that Uranus does have weather, visible as variations in color on the surface, and new photos from by the Keck II telescope in Hawaii (above) reveal the ice giant’s meteorology in more detail than ever before. The scalloped pattern near the equator is a ring of clouds; the busy, blue-flecked cap at the right end—the planet’s North Pole—are storms.
For sunny weather, try another planet: this one gets sunlight hundreds times weaker than we do on Earth, and the temperature of its upper atmosphere drops as low as -371 F, making it the coldest planet in the solar system.
Image via Lawrence Sromovsky, Pat Fry, Heidi Hammel, Imke de Pater/University of Wisconsin
Both Uranus and Neptune have quirky magnetic poles—they’re located about 60 degrees off the geographic pole rather than very nearby, like ours is. The reason, researchers suggest in a new Nature Physics study, could be that oceans of diamond—yes, oceans of diamond—cover our solar system’s two most distant planets.
The diamond idea isn’t a new one, but it’s a terribly hard question to study because you have to get diamond to melt in the lab to study it, and this experiment was the first to document the pressure and temperature at which that happens. The mineral is notoriously hard, of course, but there’s something more: Diamond doesn’t like to stay diamond when it gets hot. When diamond is heated to extreme temperatures it physically changes, from diamond to graphite. The graphite, and not the diamond, then melts into a liquid. The trick for the scientists was to heat the diamond up while simultaneously stopping it from transforming into graphite [Discovery News].