The faint dark lines in this image captured by NASA 2001 Mars Odyssey spacecraft are caused by dust devils. As the dust devil travels along the surface it scours away the loose surface dust, revealing the darker surface beneath. Orbit Number: 58268 Latitude: -51.7254 Longitude: 17.0688 Instrument: VIS Captured: 2015-02-01 12:25 http://photojournal.jpl.nasa.gov/catalog/PIA19271