June 6, 2016

Itty bitty changes: places where the wind barely moves sand

A Piece of Mars: Not all dunes on Mars are moving at a measurable pace. This 0.96×0.45 km (0.6×0.28 mi) scene looks a lot like one I posted 3 years ago called Martian Sports. This image shows the same dunes […]
May 31, 2016

Neverending dust

A Piece of Mars: Some parts of Mars, like this one, are very dusty. This 1.92×1.1 km (1.2×0.67 mi) area has built up a thick deposit of dust that slowly buries the impact craters until they’re mere ghosts of the […]
May 23, 2016

Dune cannibals II

A Piece of Mars: This 0.96×0.54 km (0.60×0.34 mi) scene shows two sets of bedforms (dunes), each aligned in different directions. The more closely-spaced set has sharper crests, and it’s superposed on top of (and it is therefore younger than) […]
May 16, 2016

Wind shadow

A Piece of Mars: There’s a dune field migrating past a 230 m (755 ft) diameter crater, creating a 1.6 km (1 mi) long “shadow” that’s empty of dunes. Why? The rim of the crater pokes up just enough to […]
May 9, 2016

Craters and wind

A Piece of Mars: This 90 m (295 ft) crater impacted into a windy, cratered plain. It’s now partly filled with dark sand, but where did that sand come from? Looking closely you’ll see that many of the boulders that […]
May 2, 2016

Giant “combs” on Mars

A Piece of Mars: This 480×270 m (0.3×0.17 mi) scene shows a herd of 100-300 m fine-toothed combs grazing on the surface of Mars. Wait, what? No, it’s not really combs. This is actually a landscape covered by two sets […]
April 25, 2016

Old ripples

A Piece of Mars: In this 480×270 m scene (0.3×0.17 mi), there are a bunch of “ripples” spaced by 5-20 m (the quotes are because we don’t know yet if these are ripples, dunes, or some other new kind of […]
April 19, 2016

Stripes by wind and gravity

A Piece of Mars: This scene (800×450 m or 0.5×0.28 mi) is a steep slope, with high rocky outcrops on the upper right and both gullies and ripples heading downslope to the lower left. The wider, brighter stripes are gullies […]
April 11, 2016

Windy windows

A Piece of Mars: Here’s a tiny bit (0.69×0.39 km or 0.43×0.24 mi) of Jezero crater, one of the candidate landing sites for the Mars 2020 rover. On the bottom and left is high-standing volcanic terrain, former lava that flowed […]