APOD 1.6

http://apod.nasa.gov/apod/ap101003.html

Discovered by Galileo, Jupiter's moon, Io, is shown here in true color. Nasa's Galileo satellite captured the image with filters to approximate what the human eye would see. Volcanic activities cause a lot of the color variations (mostly the sulfur that comes from them). Other color variations come from molten silicate rock, which is one of two types of common minerals. The silicate mineral group have oxygen and silica as their basis. Io is covered in lava every few years and is very volcanically active. Jupiter provides a lot of tidal gravity/force, stretching Io. Some of the lava is so hot it glows in the dark.