What did the Galileo space probe discover about Jupiter's moons?

The Galileo space probe studied the Jupiter system from 1995 to 2003, gathering data that transformed our understanding of the Jovian moons. It recorded active volcanism and plasma interactions on Io, and collected data supporting the existence of subsurface liquid oceans on Europa, Ganymede, and Callisto. Additionally, Galileo found that Jupiter's faint rings are made of dust from impacts on its small inner moons and discovered exospheres around Europa, Ganymede, and Callisto.

What we know

• Galileo recorded active volcanism and plasma interactions on the moon Io. [4]
• Data collected by Galileo supported the theory of a liquid ocean beneath Europa's icy surface, alongside indications of similar liquid-saltwater layers on Ganymede and Callisto. [4]
• The spacecraft discovered new evidence for exospheres surrounding Europa, Ganymede, and Callisto. [4]
• Galileo discovered that Jupiter's faint ring system consists of dust generated by impact events on the four small inner moons. [2, 4]

Where to go next

• what caused itWhy was the Galileo space probe intentionally destroyed?
• what followedHow did Galileo's mission impact our understanding of Europa?
• how it workedHow did Galileo study Jupiter and its moons?
• the bigger pictureWhat are the Galilean moons?
• whenWhen did Galileo arrive at Jupiter?
• an unexpected connectionHow does an asteroid moon connect to Jupiter's ring system?While exploring the Jupiter system, the Galileo probe also discovered Dactyl, the first known asteroid moon, demonstrating the wide scope of impacts and dust dynamics across the solar system.

Sources

• [1]Galileo (Wikidata Q105425030) · CC0 1.0
• [2]Galileo (spacecraft) · CC BY-SA 4.0
• [3]Galilean moons · CC BY-SA 4.0
• [4]Galileo project · CC BY-SA 4.0
• [5]Space probe · CC BY-SA 4.0