Aurora on Saturn
Photograph courtesy NASA, ESA, J. Clarke (Boston University), and Z. Levay (STScI)
Streams of charged particles blasted from the sun collide with Saturn's magnetic field, creating an aurora on the planet's south pole. Unlike Earth's relatively short-lived auroras, Saturn's can last for days. Scientists combined ultraviolet images of the auroras, taken by Hubble over a period of days, with visible-light images of the ringed planet. In this view the aurora appears blue because of the ultraviolet camera, but a Saturn-based observer would see red light flashes.