Io was discovered by Galileo Galilei on January, 1610 using a 20x-power, refracting telescope
at the University of Padua. Io is one of the most volcanically active object in the solar system.
Io gets the name of a character from Greek mythology. Io was one of Zeus' many maidens that he took a fancy (in Roman mythology, Zeus is identified with Jupiter). This name was suggested by the astronomer Simon Marius soon after its discovery, but it was not used until the mid-twentieth century.
Learn more about Io at Wikipedia or visit the recommended links.
Further Reading
Text based on Wikipedia,
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