burial

January 12, 2015

Bearded craters and dunes

A piece of Mars: This 600×450 m (1969×1476 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 […]
December 19, 2014

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 […]
June 24, 2014

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 […]
May 5, 2014

The wind giveth and the wind taketh away

A piece of Mars: In the center of this image is a 270 m crater (885 ft) that was nearly buried, along with the surrounding terrain, by dust. Since then, wind from the upper left has scoured the dust deposit, […]
December 11, 2013

The holes get filled in

A piece of Mars: Sand that moves into holes in the ground tends to get stuck there. That’s why this round hole ~150 m across, which was probably once a crater, is now brimming with sand and capped by ripples. […]
October 11, 2013

Relentless wind

A piece of Mars: This is what the relentless work of the wind can do. That vaguely circular structure in the center of the image is probably the remains of a ~150 m diameter impact crater. Since it formed, it’s […]
June 17, 2013

Hills, boulders, and wind

A piece of Mars: In the lower left of the image, a small hill stands above a plain partly covered by stabilized ripples. Boulders have rolled down the hill as it slowly erodes. If these ripples aren’t ever activated by […]