Nili Patera Dune Field

This Themis image assists scientists in their investigation of the north polar sand sea and isolated dune fields at lower latitudes. Sand seas on Earth are often called 'ergs', an Arabic name for dune field. A sand sea differs from a dune field in two ways: 1) a sand sea has a large regional extent,and 2) the individual dunes are large in size and complex in form.
This VIS image shows a dune field within Nili Patera, the northern caldera of a large volcanic complex in Syrtis Major. The brighter lava flow to the northeast of the dune field is made of lava of a slightly different composition than the lava beneath it.