Who would ever imagine that sand dunes could look so incredible? In this beautiful image, sand trapped in an impact crater in the Red Planet's Moachis Terra region have been sculpted by the winds of Mars into a vast and variegated landscape.
But photos like this have far more to offer than their beauty — they also allow scientists to study one of the fastest, most dynamic geological processes in the universe, providing us with incredible insights into Mars' history.
More than 21,000 images have been captured by NASA's HiRISE telescope since it began taking photos of the Red Planet's surface in late 2006. Photos like the one up top [hi-res available here] are of particular interest to scientists studying what are known as "aeolian processes" — i.e. the study of landforms formed by wind (Aeolus is the wind god in Greek mythology).
Unlike many other geological processes, which can take hundreds of thousands of years to change in any dramatic or visibly noticeable way, the wind-crafted sands of Mars' surface are continually changing at a pace so rapid, we've managed to visualize their movement even in the few short years we've been observing them.
How fast various "aeolian bedforms" (dunes and ripples) migrate across the planet's surface, how quickly they settle into the planet's various topographical features, whether or not some bedforms even migrate at all — these are just a few examples of the questions planetary scientists are using images like this to understand; and the answers they find will help us make sense of Mars' geological and climatological past, present, and future.