For all its serene blue beauty from afar, Uranus hides a detail that would make a visitor recoil: its cloud tops are laced with hydrogen sulfide, the very gas that gives rotten eggs their stench, so U

Picture Uranus the way the Voyager cameras showed it. A smooth, nearly featureless ball the color of shallow tropical water, drifting through the dark with none of Jupiter’s angry stripes or Saturn’s bright rings to catch the eye. It looks calm. It l... [3733 chars]