A huge dust cloud blown westward from the Algerian desert is now wafting over the southeastern United States. The cloud, about the size of the entire continent, was expected to produce dramatic sunsets and possibly a light coating of red-brown dust on vehicles from Florida to Texas. This image, captured by JPL's Multi-angle Imaging SpectroRadiometer (MISR) aboard the NASA Earth Observing System's Terra Satellite on July 20, 2005, shows the dust cloud just off the west coast of Africa near Mauritania and Senegal. The image covers about 1,800 kilometers (1,200 miles) north-south, and 400 kilometers (260 miles) east-west. MISR, which views Earth at nine different angles in four wavelengths, can derive the amount, size and shape of airborne particles. This means it can distinguish desert dust, by far the most common non-spherical atmospheric aerosol, from pollution and forest fire particles, which are typically spherical. This image was taken by MISR's 26 degree forward-viewing camera on Terra Orbit 29724, Path 208, Blocks 69-81.
The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously from pole to pole, and the entire globe about once per week. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.