By June 25, 2012, Saharan dust had spread across the Canary Islands and Madeira. The dust started blowing a couple days earlier in Algeria and Mali, and traveled hundreds of kilometers toward the northwest. Over the Atlantic Ocean, the dust made a giant turn toward the east, in the direction of the Mediterranean Sea.
The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this natural-color image on June 25. Immediately off the shores of Western Sahara and Morocco, the dust was thin enough to allow a glimpse of the water surface below. Farther away from shore, especially north of the Madeira, the dust was thicker, and mingled with clouds in the west.