Aliens

S1, E5: All life on Earth needs water so the search for aliens in the solar system has followed the search for water. Professor Brian Cox examines the patterns in the ice on Jupiter's moon Europa, which reveal an ocean far below with more potentially life-giving water than all the oceans on Earth. But of all the wonders of the solar system forged by the laws of nature, there is one that stands out as Brian reveals the greatest wonder of them all.