The creator of Avatar was guest of honor at a CalTech panel discussion of the science behind the most successful movie ever. Cameron is also on the Mars Science Laboratory rover team. Emily Lakdawalla has lots of good news from the Planetary Society blog. Bill Nye is on the road for this week's commentary. How do Bruce Betts and Mat Kaplan fit an 'On the Road' movie into this week's What's Up, and still have time for a new space trivia contest?