Mercury Messenger: Surprise!
September 30, 2011
As boring as the moon? Just a burned-out cinder? Not Mercury. True to tradition for planetary exploration, the MESSENGER spacecraft has served up a plate of surprises about the innermost planet. In orbit since March, the ship is sending theorists back to the drawing board to figure out a number of puzzling phenomena, some unique to Mercury. Commentators fall into two categories: those that are flabbergasted, and those who say all is well.