Sunlight and oil colored the surface waters of the Gulf of Mexico around the Mississippi Delta on May 18, 2010. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite acquired this natural-color image the same day.
The diagonal stripes mark the boundaries between each rotation of the scanning mirror that MODIS uses to observe light reflected from the Earth; the stripes are perpendicular to the satellite’s path. These scan lines are accentuated by sunglint—the mirror-like reflection of the Sun off the water.
Besides hinting at the sensor’s scans, the sunglint also illuminates oil slicks on the sea surface. Bright oil slicks appear east and southeast of the delta. As in earlier images, the oil slick spans many kilometers off the delta. Not all of the pale-hued water, however, is slicked with oil. As an image from April 25 shows, the Mississippi Delta is typically surrounded by sediment-clogged freshwater. Along the left edge of the image, the camel-toned water is probably freshwater filled with sediment.