Portal:Astronomy/Featured/April 2005

True color image taken by the Galileo probe

Io (eye'-oh, Greek Ιώ) is the innermost of the four Galilean moons of Jupiter. It is named after the Greek mythological figure Io, one of the many lovers of Zeus (who is also known as Jupiter in the Roman mythology).

Although the name "Io" was suggested by Simon Marius soon after its discovery in 1610, this name and the names of the other Galilean satellites fell into disfavor for a considerable time, and were not revived in common use until the mid-20th century. In much of the earlier astronomical literature, Io is simply referred to by its Roman numeral designation as "Jupiter I", or simply as "the first satellite of Jupiter".

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