Here is a fantastic, educational handout packed with information and facts not only about the planets in our solar system, but also regarding major moons and their surface features, dwarf planets, comets, and asteroids. 

Statistics and general information about the volcanic moon of Jupiter. Good comparison, with graphics, of Io's volcanoes and Earthly geysers.

What's it like on Jupiter's moon, Io? Find out in this short, illustrated tutorial.

This is the homepage of all of the archived information about and from the Galileo Mission. Included is data from the flybys of Venus, Earth, Moon, and Asteroids Gaspra and Ida, as well as the current data from Jupiter and its moons. See...

This site from NASA has information on the Galileo space mission, which launched in October 1989. In spite of technical problems, Galileo transmitted enormous amounts of new data, especially about Jupiter and its satellites and rings,...

Using an interesting and intriguing format, this page discusses the question of "How does one measure the speed of light." Explanation focuses on Galileo's and Roemer's efforts to obtain a reasonable value. Also discusses Heinrich...