Category: Uncategorized

Wavy dunes and straight dunes

A Piece of Mars: The dunes here are ~40 m (131 ft) apart and ~200 m (219 yd) long. (They're not really dunes, but rather a windblown thing nearly unique to Mars that we call TARs.) Look carefully and you'll ...

The crazy laciness of martian TARs

A Piece of Mars: Take a look at the windblown stuff in this 0.55x0.625 km (0.34x0.39 mi) scene. Those are intricate patterns of a sort of dune-ripple thing that forms all over on Mars, but not so much on Earth. ...

The thinnest landslides

A Piece of Mars: In the dustiest regions of Mars, steep slopes occasionally produce very thin avalanches of dust, revealing a darker surface under the top layer of dust. This shows one that is 610 m (0.38 mi) long, running ...

Dunes fighting for survival

A Piece of Mars: Having a bad day? You're in good company with these dunes in this 0.96x0.48 km (0.6x0.3 mi) scene. The gray barchanoid dunes are covered in ripples, as the wind valiantly tries to push the sand to ...

Weird and wild southern polar dunes

A Piece of Mars: This 0.96x0.48 km (0.6x0.3 mi) scene shows a bit of a south polar dune field. The more recently-active dark sand is rippled, but there are bright splotches where something else has happened. Presumably it's ground ice ...

Is it an old fossil barchan dune?

A Piece of Mars: There are many barchans on Mars, those lovely isolated crescent-shaped dunes. In a few places there are what looks like ancient preserved barchans, now lithified. The mound in the center of this 0.96x0.54 km (0.6x0.33 mi) ...

Two directions

A Piece of Mars: Sometimes I just want to show the interior of a dune field, because it's full of waves: ripples and dune crests, slip faces, all of which signs of movement. The dunes in this 0.67x0.47 km (0.41x0.29 ...

Where on Mars is this dune?

A Piece of Mars: This 0.48x0.27 km (0.3x0.17 mi) scene shows a rotund barchan dune. Can you tell from looking at it where on Mars it might be? To me the most obvious feature are the bumpy piles at the ...

Mars’ giant sweaters

A Piece of Mars: Sometimes in the floors of small craters, the wind blows in from several directions to produce odd polygon-shaped dunes that look like crochet (maybe Mars is making sweaters for its craters - it is, after all, ...

The trail of a dune

A Piece of Mars: A low, broad dune occupies the center of this 800x450 m (0.5x0.28 mi) scene, blown by a dominant wind towards the lower left. The slip face on the lee side has several small avalanches, formed as ...