On July 14, 2010, a silvery gray patch of oil stretched across the Gulf of Mexico about 80 kilometers (50 miles) southeast of the tip of the Mississippi River Delta. This photo-like image was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite at 1:55 p.m. Central Daylight Time.
The largest oil slick is located in the center of the image, but a few isolated ribbons of oil are visible to the east. The tan-colored waters around the river delta are full of sediment.
Southeast of the main oil patch, a very dark region may also be oil-covered. Oil smooths the water surface and changes the way it reflects light back to the satellite. Depending on the location of the oil, the angle of incoming sunlight, and the satellite viewing angle, oil-covered waters may appear much brighter or much darker than surrounding oil-free water.