In the windless red dunescape of a Strange Alien Planet, something was kicking up dust.

A robot named Bobby with its upper body stuck in a dune was spinning its two wheels with all its might. The right wheel dug furiously into the sand, while the left one spun haltingly in the vacuum. Over the course of an hour, it stirred up a reddish cloud. As Bobby was rocked back and forth by the exertion of its own motor, it calculated the probability of exiting the dune at being less than 1 to 100 against.

Something caught against its right wheel and it shot out of dune, out of the dust cloud, into the airless atmosphere. As Boby's frame cartwheeled through starry sky, it began to calculate the probability of landing again.