August 7, 2017

Exhumed dunes!

A Piece of Mars: The large dunes in the middle of this 375×450 m (0.23×0.28 mi) scene run along a valley (the small dunes at top and bottom are on high ground). What’s amazing about this is that the ends […]
May 22, 2017

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 0.96×0.54 km (0.6×0.33 mi) […]
January 30, 2017

Dunes + Craters = Mars

A Piece of Mars: How do you tell when a planetary landscape shows Mars, instead of Mercury or the Moon or Europa? The easiest way to tell is to look for both craters and dunes, like what’s shown here in […]
January 3, 2017

Crater ejecta on old ripples

A Piece of Mars: Mars rarely does anything without drama. Long ago in this 0.96×0.54 km (0.6×0.34 mi) scene, large ripples formed and then, presumably, lithified (turned into rock). Some time after that, an impact formed the crater in the […]
December 12, 2016

Them that make ripples and them that don’t

A Piece of Mars: Higher ground is to the left. You’re seeing a tan layer sandwiched between two gray layers in this 0.96×0.54 km (0.6×0.34 mi) scene. Large ripples have accumulated in the lowest area to the right, which is […]