Io has often been described as looking like a pizza covered with melted cheese, tomato sauce and olives. The reason for this distinct surface is its vast number of active volcanoes. There are hundreds of volcanoes scattered over the surface of the moon, which is a bit larger than Earth’s Moon. Many of the volcanoes are still active and Voyager 1 and 2 were able to capture pictures of erupting volcanoes with plumes as tall as 190 miles.
The path of Io around Jupiter is highly elliptical causing
the tidal forces exerted on the moon to be immense. The effect of this
is that the solid body of the moon can bulge out to almost 330 feet.
This movement makes the moon incredibly hot, keeping the subsurface
crust in a liquid state. This liquid sub-layer is one of the reasons
for the high volcanic activity. One result of the volcanic activity is
that there are very few crater marks as new lava is constantly filling
in any craters that are created. Because of this, Io has a very young
surface. There are three datasets available for Io. This dataset shows the
surface of the moon as does Io, Moon of Jupiter (USGS). Volcanoes of IO starts with the surface of Io, then
highlights the locations of 26 major volcanoes on Io and finally shows
the surface again.