Jupiter’s Moon Io is Having Volcanic Spasm

A huge eruption on Jupiter’s moon Io has been captured in pictures taken over a period of five months. This eruption affected an area 250 miles across on the Pillan Patera, as its volcano spews out sulfurous material. The sulfur takes on different colors depending on its temperature, so this area looks like a mess of yellow, orange, red and brownish blotches.
It is also interesting to speculate if Io has an iron core, which accounts for the moon having its own magnetic field.
See full story here at http://solarsystem.nasa.gov/planets/profile.cfm?Object=Io