Maybe it wasn’t “the comet of the century,” but ISON has left a scientific legacy that is beyond compare. That’s according to Karl Battams of NASA’s Comet ISON Observing Campaign on this week’s show. Bill Nye’s video letter to President Obama has gone viral! He talks with Mat about it. Bruce Betts looks back to Apollo 17 in this week’s What’s Up, which sees the return of the Year in Space wall calendar as the space trivia contest prize.