Dust formed a giant arc over the Red Sea on June 20, 2012. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured this natural-color image the same day. Dust stretched from hundreds of kilometers inland in Sudan across the Red Sea, skirting the border of Eritrea, and not quite reaching the shores of Saudi Arabia.
A vast network of impermanent rivers, or wadis, stretches across Sudan. Fine sediments from these wadis can be lofted into the air and carried long distances by wind. This image is from the MODIS afternoon overpass. The LANCE MODIS Rapid Response Team has also provided an image from the morning overpass acquired by the Terra satellite.