Io
Earth's moon is slightly smaller than Io. Zeus loved his maiden Io. Io has volcanoes and 400 of them are active.
Io was discovered by Galileo and Marius in 1610. Its distance from Earth: 390;400;000 mile. (KM is 628;300;000.) Io is one of the exotic solar system places. Io orbits around Jupiter. Io is the innermost of the four Galilean moons of the planet Jupiter. The atmosphere of Io is 90% sulfur dioxide. Io is the most active object in the solar system. Io has very many varieties of terrains. Io is 422,000 km from Jupiter. Io has no water. Io’s surface is radically different from any other body in the solar system.
Resources
http://en.wikipedia.org/wiki/Io_(moon)
http://nineplanets.org/io.html