NASA/JPL/University of Arizona
The Galileo spacecraft captured this global view of Io, the third largest of Jupiter’s moons. Possessing over 400 active volcanoes, it is the most volcanically active body in our solar system. Its surface is being constantly renewed by molten lava and the strong presence of sulfurous compounds gives the moon its largely golden color. Red deposits are believed to be condensed sulfur gas and the black areas are still-warm lava.
NASA/JPL-Caltech/University of Arizona
These images, also taken by the Galileo spacecraft, provide a close-up of Pele (above) and Tupan Patera (below).
Pele is a very active volcano, whose eruptions deposit thick red rings of sulfur gas around its summit. The ring in the image is more than 808 miles (1,300 kilometers) in diameter.
Tupan Patera is a volcanic depression about 47 miles (75 kilometers) wide. The term “patera” is used for broad, shallow bowl-shaped features on a planet’s surface. They can be created via impact or volcanism. Io has 26 volcanic patera.