NUBES SOBRE EL SAHARA ► Cloud Bands Over the Western Sahara Desert, Mauritania

Cloud Bands Over the Western Sahara Desert, Mauritania

Cloud Bands Over the Western Sahara Desert, Mauritania

01/27/2014 11:00 AM EST

This photograph of cloud bands over southern Mauritania was taken from  the International Space Station with an oblique angle such that the cloud  shadows are a prominent part of the view. Beneath the clouds, the plateau  of dark sedimentary rocks appears as a ragged, near-vertical escarpment  (image top right). Isolated remnants of the plateau appear as dark mesas (flat-topped hills)  across the top and near the center of the image. The escarpment is about  250 meters high, with a field of orange-colored dunes at the base  (image upper right).  Prevailing winds in this part of the Sahara Desert blow from the northeast.  (Note that north is to the right.) The wavy dunes are aligned transverse  (roughly right angles) to these winds. The sand that makes the dunes is blown in from a zone immediately  upwind (just out of the bottom of the image), where dry river beds and  dry lakes provide large quantities of mobile sand. This pattern is typical  in the western Sahara Desert, where plateau surfaces are mostly dune  free and dune fields are located in the surrounding lowlands. Larger rivers  deposit sandy sediment on the few occasions when they flow, sometimes  only once in decades. Astronaut photograph ISS038-E-26862 was acquired  on Jan. 8, 2014, with a Nikon D3S digital camera using a 180 millimeter  lens, and is provided by the ISS Crew Earth Observations experiment  and Image Science & Analysis Laboratory, Johnson Space Center.  The image was taken by the Expedition 38 crew. It has been cropped  and enhanced to improve contrast, and lens artifacts have been removed.  > View annotated image Image Credit: NASA Caption: M. Justin Wilkinson, Jacobs at NASA-JSC el dispensador dice: nubes esperadas, nubes inesperadas, arenas abiertas, arenas cerradas, espejismos de oasis, fuentes resguardadas, si no sabes de almas, tampoco de aguas, andar sediento, pierde las calmas... ¿hacia dónde vas, si no conoces nada?, ¿sabes qué te espera, detrás de las dunas?, hay sombras cortas, hay sombras largas, hay huellas abandonadas, por seres sin alma, una paz olvidada, otra negada, quien deconoce las arenas, no se adentra en el Sahara... ven por aquí, toma distancia, observa lo que enseña, el contemplar la nada, por allí hay fuentes, que no dicen nada, sólo las piedras, guían a las almas, toma vuelo, adquiere perspectiva, verás qué diferente, se ve desde arriba, todo parece ordenado, acomodado, quien no sabe de ayeres, tampoco reconoce los pasados... no te aventures a futuros cercanos, detrás de los horizontes, emergen lejanos, aún cuando estén... al alcance de la mano. ENERO 29, 2014.-