Sir Arthur Clarke: A Tribute

You'll hear Arthur's greeting to the future Martians recorded for Visions of Mars, now racing to the Red Planet on the Phoenix Lander. Also his last Planetary Radio interview, covering everything from life on Mars to hobbits. James D. Burke, a longtime friend of Arthur's, reminisces. Emily Lakdawalla returns with a new Q&A feature, while Bruce and Mat count their blessings and give away another t-shirt in the space trivia contest.