Sand Dunes near the North Pole
This HiRISE image shows some large sand dunes near the North Pole of Mars. The picture was taken in Martian summertime, with only small patches of ice remaining at the surface: this show up as bright, somewhat blue, spots on slopes that provide some shading from the sun.
Geologists would classify these dunes as “sand-starved” because the ground between the dunes has almost no sand. This ground shows a pattern of cracks that is typical of icy permafrost that undergoes seasonal expansion and contraction. It is also possible that this subsurface ice exists inside the dunes. If so, the dunes are not currently moving, being “stabilized” by this ice.
Image cutout is less than 1 km (under a mile) top to bottom and the spacecraft altitude was 317 km (197 mi). For full observation details including images with scale bars, visit the source link.
NASA/JPL-Caltech/Arizona
Sand Dunes near the North Pole
This HiRISE image shows some large sand dunes near the North Pole of Mars. The picture was taken in Martian summertime, with only small patches of ice remaining at the surface: this show up as bright, somewhat blue, spots on slopes that provide some shading from the sun.
Geologists would classify these dunes as “sand-starved” because the ground between the dunes has almost no sand. This ground shows a pattern of cracks that is typical of icy permafrost that undergoes seasonal expansion and contraction. It is also possible that this subsurface ice exists inside the dunes. If so, the dunes are not currently moving, being “stabilized” by this ice.
Image cutout is less than 1 km (under a mile) top to bottom and the spacecraft altitude was 317 km (197 mi). For full observation details including images with scale bars, visit the source link.
NASA/JPL-Caltech/Arizona