The Universe is massive. There are at least one hundred billion stars in the Milky Way Galaxy alone. And there are at least one hundred billion galaxies in our Universe. That means there are a lot of worlds we haven't explored. So is it possible that there is life beyond Earth? What is needed for Earth life, and what would alien life look like? How do scientists explore faraway worlds for signs of alien life? Discover the technology and research scientists are using to find answers.