Saturn's northern aurora in motion

An aurora, shining high above the northern part of Saturn, moves from the night side to the day side of the planet in this movie recorded by Cassini. These observations, taken over four days, represent the first visible-light video of Saturn's auroras. They show tall auroral curtains, rapidly changing over time when viewed at the limb, or edge, of the planet's northern hemisphere. The sequence of images also reveals that Saturn's auroral curtains, the sheet-like formations of light-emitting atmospheric molecules, stretch up along Saturn's magnetic field and reach heights of more than 1,200 kilometers above the planet's limb. These are the tallest known "northern lights" in the solar system. The images were captured in black and white, but the aurora in this movie is shown in a false orange color to distinguish it from background noise in the images.