When 2001 was written, Io, Europa, Ganymede, and Callisto were mere pinpoints of light in even the most powerful telescope; now they are worlds, each unique, and one of them—Io—is the most volcanically active body in the Solar System.
Arthur C. Clarke
When 2001 was written, Io, Europa, Ganymede, and Callisto were mere pinpoints of light in even the most powerful telescope; now they are worlds, each unique, and one of them—Io—is the most volcanically active body in the Solar System.