Europa is the smallest of the four Galilei moons orbiting Jupiter. It is the second of the four major moons found by Galileo Galilei on 8 January 1610 in terms of proximity to the planet, hence it has been named Jupiter’s Moon ‘II’. The surface of the satellite with a diameter of 3000 kilometers is covered with ice. It is believed that Europa is an ocean that covers the entire satellite under the thick ice sheet, and therefore life on Europa may be possible. In recent discoveries, traces of the Great Lakes have been found under the ice layers.
The reason this satellite is also called veined is because of the red lines that still remain a mystery and look like veins when viewed from the sky.