What is Callisto?
Q: What is Callisto?
A: Callisto is a moon of the planet Jupiter, discovered in 1610 by Galileo Galilei and named after Kallisto. It is the second largest moon orbiting Jupiter, after Ganymede, and the third largest moon in the Solar System.
Q: How big is Callisto compared to Mercury?
A: Callisto is almost the same size as Mercury, being 99% the diameter of the planet, but it is much less massive.
Q: Where does Callisto orbit around Jupiter?
A: Of the four Galilean moons of Jupiter, Callisto orbits farthest out with an orbital radius of about 1,880,000 kilometres.
Q: What are some notable features on its surface?
A: Notable surface features include multi-ring structures, impact craters in different shapes, and chains of craters (known as catenae) and associated scarps, ridges and deposits. On a smaller scale there are frosted hill tops surrounded by a smooth blanket of dark material in valleys.
Q: What type of atmosphere surrounds Callisto?
A: Callisto is surrounded by an extremely thin atmosphere made out of carbon dioxide and probably oxygen molecules. There is also a rather intense ionosphere.
Q: Is there any possibility for life on this moon? A: An ocean may exist within Callisto which could mean that life might exist; however this possibility is less likely than on nearby Europa.
