Planetary Radio is the weekly adventure on the final frontier produced by the Planetary Society and it's CEO, Bill Nye the Science Guy. Listen to host Mat Kaplan's conversations with the scientists, engineers, dreamers and leaders at the forefront of space exploration.  You'll also hear our regular segments with Bill, "Planetary Evangelist" Emily Lakdawalla, and Director of Science and Technology Bruce Betts. Enter the weekly space trivia contest for your chance to win out-of-this-world prizes!