By observing the changing patterns in sand dunes, scientists can
learn about the interaction between the Martian surface and the
atmosphere. Dune activity can help us understand that rate at
which the Martian wind moves sediments around, as well as to
estimate how long it takes for windblown sand to abrade the
surfaces of rocks; not to mention our Mars landers. Dunes were
first detected by the Mariner 9
spacecraft in the early 1970s, and are actively studied by the
Mars Global Surveyor
orbiter today.