Wednesday, August 18, 2010

Dune Field in Noachis Terra

This dune field is on the floor of a small crater in Noachis Terra located in the southern hemisphere of Mars.

The slip faces of the dunes have multiple directions, indicating that there were several wind directions and changes in wind strength when the dunes formed. The dominant dune type are transverse dunes (oriented perpendicular to the prevailing wind direction), with modified barchans (crescent-shaped dunes) in the northern region of the field and incipient linear dunes in the southern region.

The bright material scattered throughout the dune troughs, as well as at the bottom of the image, are outcrops of underlying bedrock.

The bottom of the image clearly displays a mass of dark dust devil tracks. Dust devils are wind funnels that suck up dust as they travel over the surface exposing the dark sandy substrate.

Photo credit: NASA/JPL/University of Arizona

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