Ditches, Devils and Dunes
There’s a lot going on in this image from the Mars Reconnaissance Orbiter’s HiRISE camera…swirling dust devil tracks paint dark streaks over the sand dunes within Russell Crater (click here for a larger view of the region) while long “peculiar” ditches run snakelike down the crater’s sloped walls. Click the image above for a larger version…the structure of the ditches is interesting, to say the least. How they were formed is of special interest to planetary scientists.
Dust devils are common on Mars, forming in the same way as they do in hot, dry areas on Earth: air near the surface warms and rises upwards rapidly in spinning columns, carrying loose particles of dry soil with it. On Mars these dust devils will make darker subsurface sand very visible to satellite cameras as they blow across the dunes. Although energetic in appearance, most Martian dust devils are too small and wispy to do much else than blow loose sand around, although in the case of the Spirit rover – on more than one occasion, in fact – a rendezvous with a devil proved very effective in cleaning off dusty solar panels!
Image: NASA/JPL/University of Arizona