Could there be life on other planets? Did life come to Earth from space? Have we already found evidence that aliens exist? #SpaceWeek2018 #DiscoverySpaceWeek Subscribe to Discovery UK for more great clips: http://www.youtube.com/subscription_center?add_user=DiscoveryTV Follow Discovery UK on ...

Watch new episodes of Ancient Aliens Saturdays at 9/8c, and stay up to date on all of your favorite History Channel shows at https://history.com/schedule. After tracking methane levels on Mars over the past few years, Elizabeth Rampe, NASA Exploration Mission Scientist, breaks the news that ...