The Phoenix lander appears to have fallen down a rabbit hole on Mars. How else to explain why it is exploring, from its stationary spot in the frigid northern plains, nearby sites called Wonderland, Cheshire Cat and Croquet Ground?

"The overarching theme is to name features - rocks, soil, trenches, dump piles - after names from fairy tales," says team member Ray Arvidson of Washington University in St Louis, Missouri, US. But sustaining the Lewis Carroll theme was a little difficult, Arvidson...