All life on Earth needs water so the search for aliens in the solar system has followed the search for water. But Brian's sixth wonder isn't a planet at all. Jupiter's moon Europa is a dazzling ball of ice etched with strange cracks. The patterns in the ice reveal that, far below, there is an ocean with more potentially life-giving water than all the oceans on Earth.
Around the world, a new generation of astronomers are hunting for the most mysterious objects in the universe - young stars, black holes, and even other forms of life. They have created a dazzling new set of super-telescopes that promise to rewrite the story of the heavens.