February 9, 2015
A piece of Mars: The smooth areas are eroded dunes, separated by fields of boulders (the scene is 1.51×1.14 km or 0.93×0.71 mi). The largest boulder near the center is 7.5 m (25 ft) across, the size of a small […]
February 2, 2015
A piece of Mars: What happens to dunes as they move over rough terrain? This is what a barchan looks like on a relatively flat surface. If the hills are smaller than the dune, then it does its best to […]
January 26, 2015
A piece of Mars: This scene (600×450 m or 1969×1476 ft) is covered in small craters, formed by the splash of a larger crater nearby. They cover everything, even the bright ripples visible on the right. So the ripples were […]
January 21, 2015
A piece of Mars: The curving ridge of a mountain has signs of many small landslides. Mantled on top of these is an older set of landslides that has been partially eroded away. The rippled edge of this older deposit […]
January 12, 2015
A piece of Mars: This 600×450 m (1969×1476 ft) scene has a complex sedimentary history. How are bearded craters and dunes formed? They weren’t always bearded. At some point, a deposit of bright material accumulated on this surface, and was […]
January 5, 2015
A piece of Mars: A long, low dune covered in long, linear ripples stretches across the scene (600×450 m; 1969×1476 ft). Dark gray areas on the dune show where sand has most recently moved. A small slip face has formed […]
December 19, 2014
A piece of Mars: Some time ago, something hit the ground on Mars and made this impact crater, right into a field of ripples. Stuff thrown up during the impact fell back down, burying the ripples with the gray ejecta […]
December 8, 2014
A piece of Mars: On the left is a steep slope leading to a hill. On the right are waves – but not waves of water or any other kind of liquid. These are dunes or very large ripples, blown […]
December 1, 2014
A piece of Mars: This circular hill is 200 m (~656 ft) across and ~48 m (~160 ft) high. It stands alone on a relatively flat plain. Why is it there? The surface here used to be ~48 m higher […]