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There are parts of Mars that are covered in a fluffy powder that is carved by the wind into odd patterns.
Medusae Fossae

The result is a surface that appears fuzzy even at HiRISE resolution, so don’t worry, HiRISE is *not* out of focus.

You can tell the camera is working just fine if you find one of the few small impact craters on this surface: those look nice and sharp. This example of fuzzy ground is from what Mars geologists have called the Medusae Fossae Formation. The origin of this material is still debated but most favor the idea that this is a thick pile of volcanic ash that has been blown here by the wind. The possible impact site in the full image might not last very long because the surface is being rapidly eroded.

Image: NASA/JPL/University of Arizona https://www.uahirise.org/hipod/ESP_071481_1795
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