Planetary Society President Jim Bell leads the PanCam team for the Mars Exploration Rovers, Spirit and Opportunity. He came to Pasadena last week to help celebrate five years on Mars. Bill Nye joined the party with a presentation about the MarsDials on the rovers. Emily Lakdawalla's Q&A looks forward to a Mars flyby by the Dawn spacecraft. Bruce Betts and Mat Kaplan join the MER party with a new What's Up segment, including a new space trivia contest.