Earth Tones On Mars
Lurking within this martian palette are not one but four dust devils, each snaking their way across the surface.
This region of Mars is named Arcadia Planitia. It’s an exciting one: it lies just northwest of the colossal Tharsis volcanic province, home to the tallest volcanoes in the entire Solar System, and is thought to host near-surface water ice, making it a possible landing site for future missions to the Red Planet.
Arcadia Planitia is reasonably flat and largely covered in old, solidified lava flows that are three billion years old at most. This image, captured by Mars Express’s High Resolution Stereo Camera (HRSC), shows the eastern part of the plain, and highlights a whole host of fascinating features.
Out of focus?
At first glance, this image may look a little blurry. While not the case, your eyes aren’t deceiving you! The air here is full of tiny particles that have been swept up and grabbed by passing winds, creating a sort of haze that makes everything seem a little out of focus. Wind plays an important role on Mars, constantly reshaping the landscape as it carries sand from one place to another.
This is especially evident here. The reddish upper part of the image is covered in streamlined rocky ridges known as ‘yardangs’, intriguing features that have been seen before by Mars Express. These ridges were carved from surface rock by sand and dust whipped up by martian wind. They resemble small clusters of parallel scratches scattered across the surface.
The yardangs sit near to a much larger curved boundary that sweeps across the frame and slices this image roughly in two. On the other side of this arc the terrain is darker; the varied colours seen here are likely due to mixes of different materials – with the reddish ground being full of iron, and the darker ground rich in silicates – and the properties of the sand particles themselves (such as density, roughness, and size, which affect where and how grains accumulate across Mars).
More imagery, ESA
Astrobiology
