Callisto

Callisto is one of Jupiter's 63 moons. Callisto is even one of Jupiter's 4 most famous moons. Callisto was discovered on January 7, 1610. Callisto is about the same size as the planet Mercury. The diameter of Callisto is 4806 km. Callisto has more impact craters than all other moons of Jupiter. Callisto consists mainly of ice and rock. Callisto consists of 40% ice and 60% rock and iron. Callisto's atmosphere consists mainly of carbon dioxide.