Mars was once a very different planet, with rivers, lakes, and — potentially — life. NASA’s latest Mars rover is on a mission to find traces of past life. What happens if it does? This is the third episode of our new four-part series, Lost Worlds. For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! [email protected] We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

Ask this episode

“What did the council decide on item 42?” — answered with the speaker and the moment.