To Earth and Back

We are all Martians … or could be, if, billions of years ago, Red Plant microbes fell to Earth and eventually evolved to us. Okay, that one’s a big “if.” But microbes can survive space travel. Meet the NASA officer whose task is to keep Earth, Mars - and the entire solar system –safe from hitchhiking bacteria. And, even if we’re not Martians (darn!), did life once thrive on the Red Planet ... and does it still today? Plus, why meteorites may be happy habitats for life. Guests: ...