lfenton

November 7, 2016

Dunes and rock hurdles in Gale crater (3D)

A Piece of Mars: Wind from the upper left is blowing dark dunes toward the lower right in this 1.92×1.08 km (1.19×0.67 mi) anaglyph (if you don’t have your red/blue 3D glasses handy, you can also check out the black […]
October 31, 2016

On Mars the wind carves stream channels

A Piece of Mars: This 1.6×2 km (1×1.24 mi) scene mostly shows what wind will do to fine-grained, weakly-consolidated surfaces. It has created topography that further strengthens wind scour in the hollows, which even leave kilometers-long grooves reminiscent of water-carved […]
October 10, 2016

The spire in Eberswalde crater

A Piece of Mars: OK, you have to bring out the red/blue glasses for this one. (Or click here if you’re missing your glasses and want the black and white version.) Eberswalde crater has some lovely layered deposits, long ago […]
October 3, 2016

Windblown: ancient and recent

A Piece of Mars: HiRISE is celebrating 10 years of success by showcasing its first high resolution image, taken back in 2006. Here is a portion of it, shown at 1/4 the full resolution (the scene is 2.5×2.5 km across). […]
September 26, 2016

Is it windblown or not?

A Piece of Mars: This 480×270 m (0.30×0.17 mi) scene shows what are being called “ridges”. Were these ridges once dunes that have now been stabilized and eroded? They have some dune-like characteristics: nearly parallel crests, one slope is steeper […]
September 19, 2016

Light and dark

A Piece of Mars: This 0.96×0.54 km (0.6×0.34 mi) late winter scene is a study in contrast. The dark top half is uniformly rippled. This is the shady surface of the main windward side of one of Mars’ biggest dunes, […]
September 12, 2016

Shades and textures

A Piece of Mars: This 480×270 m (0.3×0.17 mi) scene shows the contact between two very different terrains. On the left is a bright surface with polygonal cracks (characteristic of periglacial terrain – this is at a high latitude). On […]
September 5, 2016

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 (873×491 m, or 0.54×0.31 […]
August 29, 2016

Where does the windblown stuff come from?

A Piece of Mars: How far do windblown materials move on Mars? This scene (0.9×1.2 km, 0.56×0.75 mi) shows a bright layer of bedrock (top right) that is eroding, exposing a darker, bluish rock (bottom left). Ripples 5-20 m wide […]