complex wind
November 12, 2015
A Piece of Mars: This 480×270 m (1575×886 ft) area shows a seemingly endless field of ripples. They’re big, about 50 m (164 ft) from crest to crest, and probably about 5 m (16 ft) high. Is there a knit […]
January 5, 2015
A piece of Mars: A long, low dune covered in long, linear ripples stretches across the scene (600×450 m; 1969×1476 ft). Dark gray areas on the dune show where sand has most recently moved. A small slip face has formed […]
December 8, 2014
A piece of Mars: On the left is a steep slope leading to a hill. On the right are waves – but not waves of water or any other kind of liquid. These are dunes or very large ripples, blown […]
November 17, 2014
A piece of Mars. These are gullies on a martian hillside (upslope is to the upper right). Water may be what forms the channels, carrying soil and rocks downslope. The textured pattern of the lower slope is caused by the […]
August 25, 2014
A piece of Mars: This scene (3.9×2.5 km or 2.4×1.6 mi) shows a surface carved by two different winds: one blowing from the right and one blowing from the bottom right. They’ve formed overlapping sets of streamlined rocks called yardangs. […]
August 18, 2014
A piece of Mars: The two shadowed hills in the upper part of this frame (497×373 m or 1631×1224 ft across) rest on a flat plain covered in large ripples. On the plain the ripples are aligned north-south, formed perpendicular […]
August 14, 2014
A piece of Mars: Dunes outside the crater are straight but the ones inside the crater look like a spiderweb. Why? This image shows just how much the topography of a crater wall can affect the wind, which produces a […]
July 8, 2014
A piece of Mars: Using dunes to interpret the winds can be a tricky business. Here’s one reason why: most of the dunes here go from the upper left to lower right. But the ones inside the funky oblong crater […]
October 25, 2013
A piece of Mars: Barchan, or crescent dunes, are generally thought to form from winds blowing from a single direction. Reality isn’t usually that nice. Here are two barchans with crescent-shaped slip faces on their eastern (right) sides, indicating that […]
June 21, 2013
A piece of Mars: Yep, these are dunes shaped into polygons. Each “cell” is about 25 m (~80 ft) across. The crests of these things are outlined in blue, as if somebody traced them with a pen (well it’s stretched […]