Tag Archives: layers

Dunes carving up rock (3D)

A Piece of Mars: Get out your 3D blue/red glasses (or look here for a 2D version if you can't find them). This is a 3.2x1.8 km (2x1.13 mi) scene showing dark dunes carving lanes 50-70 m (165-230 ft) deep ...

Steno’s principles, or “how to make sense of pretty landscapes”

A Piece of Mars: Nicholas Steno was a 19th century geologist, who came up with some principles that are still used today to guide interpretation of exposed sedimentary rocks. The principles seem a bit obvious, but then some of the ...

The trail of a dune

A Piece of Mars: A low, broad dune occupies the center of this 800x450 m (0.5x0.28 mi) scene, blown by a dominant wind towards the lower left. The slip face on the lee side has several small avalanches, formed as ...

Them that make ripples and them that don’t

A Piece of Mars: Higher ground is to the left. You're seeing a tan layer sandwiched between two gray layers in this 0.96x0.54 km (0.6x0.34 mi) scene. Large ripples have accumulated in the lowest area to the right, which is ...

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 2.5x2.5 km across). ...

When the martian surface is eroded, pretty things emerge

A Piece of Mars: Just like at Earth's Grand Canyon, erosion on Mars has created some really beautiful landscapes. This 480x270 m (0.3x0.17 mi) scene shows rugged terrain that was once buried in sediment. Does the texture here represent the ...

Dune cannibals II

A Piece of Mars: This 0.96x0.54 km (0.60x0.34 mi) scene shows two sets of bedforms (dunes), each aligned in different directions. The more closely-spaced set has sharper crests, and it's superposed on top of (and it is therefore younger than) ...

Windy windows

A Piece of Mars: Here's a tiny bit (0.69x0.39 km or 0.43x0.24 mi) of Jezero crater, one of the candidate landing sites for the Mars 2020 rover. On the bottom and left is high-standing volcanic terrain, former lava that flowed ...

How far does the wind blow stuff?

A Piece of Mars: Hargrave crater has an amazing array of colorful surfaces, each of which reflects a different type of rock (this scene is 480x270 m or 0.3x0.17 mi). I like the ripples sitting on top of it all; ...

Remnants of erosion

A Piece of Mars: The gray area in the center of the 480x270 m (0.3x0.17 mi) area is an erosional remnant: once, more of this area was covered by the gray stuff, but some of it has eroded away (most ...