Date:10 July 2014
Migratory birds and military aircraft often fly in a V-shaped formation. The “V” formation greatly boosts the efficiency and range of flying birds, because all except the first fly in the upward motion of air – called upwash – from the wingtip vortices of the bird ahead.
In this image of Martian dunes in a large crater near Mawrth Vallis, some of the dunes appear to be in a V-shaped formation. For dune fields, the spacing of individual dunes is a function of sand supply, wind speed, and topography.
This image was acquired by the HiRISE camera aboard Nasa’s Mars Reconnaissance Orbiter on 30 December 2013.
Image credit: Nasa/JPL-Caltech/University of Arizona
Caption credit: Alfred McEwen