August 13, 2018

Where dunes once trod

Mars has been dusty, and that’s affecting the quality of HiRISE images (just look at the recent images in the catalog and you’ll see they’re not that great). That’s made it hard for me to choose a good one for […]
December 26, 2017

Buried by ejecta

A Piece of Mars: To see this one well you’ll have to click on the image. At the lower right, a 240 m (787 ft) diameter crater formed when a bolide hit the surface, throwing out ejecta on the surrounding […]
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 8, 2017

Sand tails

A Piece of Mars: Up on the tallest volcanoes, the wind screams downhill at night. This 500x500m (0.31×0.31 mi) scene shows how dust is carried downhill, but only that which is trapped behind boulders and crater rims sticks around. The […]
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 […]
June 27, 2016

How to hide geology on Mars

A Piece of Mars: Three things are trying to hide in this 0.96×0.48 km (0.6×0.3 mi) scene. 1) Craters are slowly being both scoured and buried by migrating sand, 2) the sand itself is hiding in the lee of crater […]
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 […]
October 5, 2015

Dune trails

A Piece of Mars: The dark dunes in this 0.96×0.54 km (0.60×0.34 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. […]
July 31, 2015

What is burying what?

A piece of Mars: There’s an egg-shaped plateau here (the whole scene is 480×270 m or 525×295 yd across, the “egg” is ~100 m long). It’s partly covered by dunes that have extended across it. Or were the dunes there […]