Shadows behind boulders

A Piece of Mars: Bright material (either dust or sand) has accumulated in the lee of wagon- to car-sized boulders in this 0.96×0.54 km (0.6×0.34 mi) scene. It’s perhaps something like the Rocknest sand shadow that Curiosity visited a few years back. The wind blows from lower right to upper left, carrying along sediment that

Erosional remnants

A Piece of Mars: The erosionally-streamlined bright areas are on high ground. They are remnants of a vast dusty mantle that once covered this whole area – the rest of it has been blown away. The surrounding regions (check out the whole image) are still covered by that mantle, but here you can see through

Landslides unlike any on Earth

A Piece of Mars: Click on this 0.96×0.54 km (0.6×0.33 mi) scene to see it in detail. Many thin, narrow landslides have formed on these dust-coated hills. As far as I’m aware, there’s nothing like this on Earth. Inside the landslide scars, there are small dusty ripples about 1.75 m (~6 ft) in wavelength, smaller

The wind paints

A Piece of Mars: For the last few billion years, the wind has (by far) moved more sediment around on Mars than any other geological process. Not tectonics, volcanism, fluvial activity, or impact cratering (although a case has been made for glacial activity). Here’s yet one more swipe at the ground, scouring off bright dust

A light touch

A Piece of Mars: This 3.2×1.8 km (2×1.1 mi) area shows terrain covered by bright dust. Dark stripes are areas where wind has lightly scoured the surface, revealing the dark material beneath. Faint bright lines criss-cross the surface – these are tracks left by dust devils. The dust devils disturb the surface but don’t lift

Frosty dunes

A piece of Mars: In this image (0.96×0.54 km or 0.6×0.33 mi), it’s late winter and the sun is barely above the horizon here near the north pole. The dunes are covered in winter frost, most of which is CO2 ice (also known as dry ice). The dark regions are those facing the sun, where

The long, low dune

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 on the southeast side of the dune, but ripples have formed on it, so there

Panda stripe dustslides

A piece of Mars: This 600×450 m (1969×1476 ft) scene of a hillside shows new, dark dustslides that slid downhill (to the lower left). Faint stripes of older dustslides are visible, covered by bright dust and small ripples. Thousands of these form every year on Mars, stretching several kilometers downslope – there is nothing quite


A piece of Mars: This is a bit of the flank of Arsia Mons, one of Mars’ great volcanoes. The big changes in topography are ancient relics of erosion by lava and great tectonic pulling. What I like is that the scene (1.58×1.18 km, or 0.98×0.74 mi) is covered in bright dust (looks a bit