Jupiter's moon Io and its shadow are hurling across the face of the biggest planet in our Solar System. Io itself is a very interesting moon, well known for its many active volcanoes. The smallest details visible on Io and Jupiter are about 150 km across. Bright patches visible on Io are regions of sulfur dioxide frost. Io is roughly the size of Earth's moon, but 2,000 times farther away.
October 4th, 1996