Callisto Scale Model

Callisto Scale Model

Scale model of Jupiter’s moon Callisto. It is a 1:7,000,000 scale model, based on an estimate of Callisto’s diameter to be 4,821 kilometres. Callisto was first discovered by Italian astronomer Galileo Galilei and is one of Jupiter's four largest moons. Named after their discoverer, the Galilean moons consist of Ganymede, Callisto, Io and Europa in descending size order.

Callisto is the outermost of Jupiter’s Galilean moons, which means that it orbits outside the gas giant's main radiation belts. This has led some scientists to suggest that it could be used to build a base for future astronauts to explore the Jupiter system. It is the second largest of the Galilean moons after Ganymede and the third largest in the whole Solar System - Callisto is around the same size as the planet Mercury, although it is significantly less dense.

Callisto's surface is one of the oldest surfaces in the Solar System having formed over four billion years ago. A lack of volcanic or tectonic activity has left the surface almost completely covered in craters - as the surface has not had significant geological activity reshaping it and removing craters. New impacts from comets and asteroids are likely to wipe out older craters, such is the extent of cratering on the surface. This heavy bombardment has been illustrated on the model, with the different light and dark colours of Callisto and its many impact craters showing up clearly. Light sections are believed to be mostly ice, whilst darker sections are areas of erosion where the ice is mixed with silicate materials.