Europa is one of Jupiter's large moons, known as Galilean moons, as they were discovered by Galileo Galilei in 1610. It is slightly smaller than our own Moon.

Io is the closest of the four large moons of Jupiter.

An eclipse of the Sun, or Solar Eclipse, occurs when the Moon comes directly between the Sun and the Earth so that the Earth lies in the shadow of the Moon.

• The Earth is the planet that we all live on.