Key facts
- Scale fact
- 4,821 kmdiameter
- Estimated age
- ~4.5 billion years
- Composition
- Rock and water ice
Callisto
4,821 kmdiameter
Visual creditVoyager 2 1979 / NASA / JPL-Caltech / Kevin M. Gill / CC BY 2.0Source: Wikimedia Commons
Details
Callisto is Jupiter's second-largest moon and the outermost of the four Galilean moons. Its ancient, heavily cratered surface records a quieter history than Io, Europa, and Ganymede, while Galileo spacecraft data suggest a possible salty ocean deep below the ice.
Callisto’s densely cratered surface has not undergone the broad resurfacing visible on Io, Europa or Ganymede, preserving impact structures from much of Solar System history. Galileo magnetic measurements are consistent with a conducting layer deep below the ice, commonly interpreted as a salty ocean, but the evidence is indirect.
Links
- Universe journey
- Asteroid belt & Jupiter
- Wikipedia
- Callisto on Wikipedia
Size neighbors
Objects near Callisto on the scale
Sources
References for Callisto
Measurements and descriptive context are compiled by the Scale of Space team from the references below. If you find an error, please let us know.
- Callisto — Wikipedia
- Visual reference: Wikimedia Commons (Voyager 2 1979 / NASA / JPL-Caltech / Kevin M. Gill, CC BY 2.0)
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Scale of Space is a scroll-based journey through the universe, placing objects on a single logarithmic scale so you can compare size across an unbroken range.
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