Europa - an icy moon of Jupiter 485 million miles away from Earth - may be our best hope for finding alien life in our solar system. Everywhere we find water on Earth, we find life. What does this mean for the search for life beyond Earth? Scientists believe that on Europa there is a liquid ocean buried beneath its icy crust . To find out if this alien ocean holds life, well need to get there, penetrate the ice shell, and navigate in an alien sea. In this episode of Explorer, well plunge headlong into the challenges of discovery on an alien world. Well meet the scientists, adventurers, and engineers who are determined to launch a mission to Europa - and follow them through the challenges, frustrations, and triumphs that come with planning a distant mission to an alien world. Through high-end CGI and quests to the edge of our planet, well go on a journey to and alien moon called Europa. To answer the basic question: Are we alone in the universe?