Jupiter & Moons
Jupiter is the fifth planet from the Sun and the largest planet in the solar system, at 1,335 times larger than the Earth.This image shows Jupiter and its four largest moons. Starting top right and moving clockwise they are Io, Ganymede, Callisto and Europa.Jupiter has 67 moons – the most of any planet in the solar system.The four largest moons were discovered by Galileo Galilei in 1610 and were named by Simon Marius in his book of 1614. Io is closest to Jupiter and is the most volcanic body in our solar system. It is thought that there may be twice as much water on Europa as there is on the Earth, with its icy surface covering a huge ocean.Ganymede is the largest moon in the solar system and is bigger than Mercury. It is the only moon to have its own magnetic field.