Tag Archives: burial

Exhumed dunes!

A Piece of Mars: The large dunes in the middle of this 375x450 m (0.23x0.28 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 ...

Sand tails

A Piece of Mars: Up on the tallest volcanoes, the wind screams downhill at night. This 500x500m (0.31x0.31 mi) scene shows how dust is carried downhill, but only that which is trapped behind boulders and crater rims sticks around. The ...

Crater ejecta on old ripples

A Piece of Mars: Mars rarely does anything without drama. Long ago in this 0.96x0.54 km (0.6x0.34 mi) scene, large ripples formed and then, presumably, lithified (turned into rock). Some time after that, an impact formed the crater in the ...

How to hide geology on Mars

A Piece of Mars: Three things are trying to hide in this 0.96x0.48 km (0.6x0.3 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 ...

Neverending dust

A Piece of Mars: Some parts of Mars, like this one, are very dusty. This 1.92x1.1 km (1.2x0.67 mi) area has built up a thick deposit of dust that slowly buries the impact craters until they're mere ghosts of the ...

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. ...

What is burying what?

A piece of Mars: There's an egg-shaped plateau here (the whole scene is 480x270 m or 525x295 yd across, the "egg" is ~100 m long). It's partly covered by dunes that have extended across it. Or were the dunes there ...

Bearded craters and dunes

A piece of Mars: This 600x450 m (1969x1476 ft) scene has a complex sedimentary history. How are bearded craters and dunes formed? They weren't always bearded. At some point, a deposit of bright material accumulated on this surface, and was ...

Wind, wind, impact(!), and then more wind…

A piece of Mars: Some time ago, something hit the ground on Mars and made this impact crater, right into a field of ripples. Stuff thrown up during the impact fell back down, burying the ripples with the gray ejecta ...

In the lee

A piece of Mars: This crater (290 m or 950 ft across) is crawling with all sorts of ripples and dunes. The wind mainly blows from the top to the bottom of the frame, and it is responsible for the ...