Planetary scientists studying photos of Mars’s ever-changing landscape have discovered a stunning formation of bedrock ridges near the planet’s equator, inside Schiaparelli Crater – but how they formed remains a mystery.
https://gizmodo.com/high-resolution-images-of-mars-reveal-a-stunning-wind-5879398
The images you see here come by way of NASA’s stunningly powerful HiRISE camera. Researchers were originally drawn to Schiaparelli by the circumferential layers that line its insides. HiRISE – which can image the planet’s surface at about 25cm per pixel all the way from orbit – allows researchers to get a good look at these layers and how they change over time.
https://gizmodo.com/this-is-hirise-the-most-powerful-camera-weve-ever-sent-5875075
“This image was targeted to look at potential changes in the distribution of dark sand compared to earlier pictures,” writes HiRISE co-investigator Nathan Bridges on the mission’s website; and while preliminary investigations have turned up no such changes, they have raised some intriguing new questions:
In this image [above], we note something that becomes apparent if we zoom in to many of the areas containing dark sand. Here, the sand is on top of periodic bedrock edges oriented semi-radially from the crater and approximately perpendicular to the layers. How did these ridges form, and what is the relationship to the sand?
The answer, Bridges says, is a mystery – though he offers that sand may be somehow “nucleating,” or collecting, on the ridges.
“This suggests that some apparent large ripples on Mars are sand nucleation sites on pre-existing topography,” he explains. “The extent of such ridges, and their relationship to sand elsewhere on the planet, can be further understood with future HiRISE images in other areas.”
[HiRISE]
