Jupiter’s Galilean moons

Jupiter’s four main moons were discovered by the astronomer Galileo Galilei in the early 17th century

Europa

1,939.7 miles

diameter

Io

2,263.8 miles

Callisto

2,995.4 miles

Ganymede

3,273.5 miles

Earth’s moon

2,159.1 miles

Europa

1,939.7 miles

diameter

Io

2,263.8 miles

Ganymede

3,273.5 miles

Earth’s moon

2,159.1 miles

Callisto

2,995.4 miles

Guardian graphic. Images: Alamy