erosion

September 25, 2012

Winds in Gale crater, ancient and young

A piece of Gale crater, Mars: Cream-colored ripples wind their way through rough terrain. Looking more closely, the rocky surface seems to be made of highly eroded parallel ridges that are nearly perpendicular to most of the ripples. These ridges […]
September 19, 2012

Squooshed craters

A piece of Mars: Impact craters are typically round circles, so when you see one that isn’t, it’s usually because something has changed its shape into something less perfectly round. These craters are squooshed on the lower right side, as […]
September 9, 2012

Valley in Mt. Sharp

A piece of Gale crater, Mars: Here’s a view of a small piece of Mt. Sharp, both from Curiosity (on the right) and from orbit (on the left, HiRISE ESP_028269_1755). A broad valley visible from the rover is revealed to […]
August 28, 2012

Feathered terrain up on Mt. Sharp, where Curiosity may one day go

A piece of Gale crater, Mars: Here is a tiny piece of feathery terrain way up high on Mt. Sharp, the mountain that Curiosity will one day climb. This is a special unit of fine-grained material that has weathered into […]
August 19, 2012

What is Mt. Sharp?

A piece of Gale crater, Mars: What exactly is Mt. Sharp, the big mountain Curiosity is set to climb up? Here’s a picture of what it is: layers and layers and layers and layers. And more layers. Probably sedimentary, but […]
August 13, 2012

Curiosity’s Grand Canyon

A piece of Gale crater, Mars (Aug. 13, 2012): Here is the wall of a large ravine cut into Mt. Sharp, the mountain of layered and eroded sediments that Curiosity will climb. Long ago, this ravine was cut by water, […]
August 10, 2012

And the wind blew

A piece of Gale crater, Mars: These are rocks on Mount Sharp, where the Curiosity rover will be headed in the coming months. Like many of the surfaces in Gale crater, these have been streamlined by sandblasting over the eons. […]
August 3, 2012

A beautiful tangle

A piece of Mars: Compare this with my post five days ago and you might think the scenes are similar. In fact they’re not. In the previous case sedimentary layers were carved out by the wind, leaving behind swirly patterns […]
July 29, 2012

Wind erodes rocks into swirls

A piece of Mars: When the wind sandblasts at layered rocks, some pretty swirly patterns emerge. These are flat layers that take on a stacked wedding-cake appearance on an outcrop elongated by the wind. The direction of the stacks indicates […]
July 26, 2012

And then the wind swept through

A piece of Mars: Wind streaks are a common sight on Mars. They are formed either by the wind blowing stuff away or blowing stuff in, and it can be quite difficult to tell which is which. In this case, […]
July 9, 2012

Dunes all gone

A piece of Mars: Way up in the cold northern plains of Mars, some of the dunes are being blown away slowly by the wind. Here are some that are barely there yet — dark patches of sand in the […]
June 20, 2012

Dune bones

A piece of Mars: The thin stripes within stripes are the bones of dunes. You’re seeing old dunes that have had their tops eroded away so you’re seeing into their insides, as if you were dissecting them in a biology […]