Tag Archives: barchan

Black and tan

A Piece of Mars: Dunes in the top row in this 0.73x0.47 km (0.46x0.29 mi) scene are dark but those in the lower row are brighter. Why? They're all probably made out of the same kind of sand, which is ...

Dust trapped on the lee side

A Piece of Mars: This 0.95x1 km (.59x.62 mi) scene shows the center of a small dune field. The dunes are shaped by three winds blowing from three different directions: from the west-southwest, east, and south. The north-facing slopes are ...

Mars’ giant bubble wrap

A Piece of Mars: This 0.7x0.5 km (0.43x.31 mi) scene shows Mars' giant yellow bubble wrap, with each "bubble" about 100 m across (seriously, don't you want to pop them?). These are actually a type of dune called a "dome ...

Experimenting with 3D views

A Piece of Mars: I often use JMARS to visualize Mars data sets, especially images. They've recently updated their 3D layer, allowing folks to make lovely vistas by overlaying DTMs with images. I'm new at this, but I'll experiment and ...

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) ...

Curiosity, recovering from the Bagnold dunes campaign

A Piece of Mars: You'll probably want to click on this image to see the whole thing, it's pretty big, and it's worth seeing. This 850x550 m (0.53x0.34 mi) scene shows the barchanoid dunes of the Bagnold dune field, imperceptibly ...

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 ...

Eroded dune

A Piece of Mars: Barchan dunes on Mars have a characteristic crescent shape, with a steep slope ("slip face") on the inside of the sharpest curve (see examples like this, this, these, or this). This image (873x491 m, or 0.54x0.31 ...

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 0.96x0.45 km (0.6x0.28 mi) scene looks a lot like one I posted 3 years ago called Martian Sports. This image shows the same dunes ...

Dune trails

A Piece of Mars: The dark dunes in this 0.96x0.54 km (0.60x0.34 mi) scene are slowly migrating towards the lower left. Look closer and you'll see brighter ripples between the dunes - the biggest ones are ~8m (26 ft) apart. ...