We don't hear too much about natural dust, the kind that the winds loft from deserts and dry lakebeds into the air and carries for hundreds of kilometers, crossing oceans and continents, but we should. Plumes of dust connect the atmosphere, the oceans and the forests, and affect the most fundamental processes of life on our planet. Scientists believe that dust has profound and somewhat mysterious influences on atmospheric chemistry, solar heat exchange and nutrient supply to the oceans and rain forests. What those influences are, exactly, is the subject of much study and is still somewhat mysterious--the story of dust shows just how complex our natural world is, and how difficult it is to understand it. For more, see our February feature story, 'Swept From Africa to the Amazon'.

Here are some spectacular natural-color images of dust storms taken by NASA's Aqua satellite, which was launched on May 4, 2002. The images were all taken with an instrument called the Moderate Resolution Imaging Spectroradiometer MODIS, one of six aboard Aqua.

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