Astronomy Picture of the Day

Explanation: Serene blue hues highlight this view of Saturn's northern hemisphere from the Cassini spacecraft. The image has been adjusted to approximate the natural blue colour of visible sunlight scattered by the gas giant's upper atmosphere. Saturn's famous rings cast the dark shadows stretching across the frame with infamous cratered moon Mimas lurking at the lower left. Orbiting beyond the main inner rings, Mimas itself is 400 kilometres across and lies nearly 200,000 kilometres, over 3 Saturn radii, from the centre of the planet. Still, Mimas orbits within Saturn's faint and tenuous outer E ring.