English: NASA’s Terra satellite flew over the southern Caspian Sea on December 12, 2016, allowing the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard that satellite to capture this true-color image of the Sea and surrounding landscape.

The Caspian Sea is the world’s largest inland body of water, covering about 143,200 square miles (371,000 square kilometers). The waters are salty, with salinity increasing from the north to the south. The nearly round Kara-Bogaz-Gol, located on the lake’s eastern perimeter, is a saline inlet of the Caspian Sea. Kara-Bogaz-Gol is partially hidden under cloud in this image.

The southern Caspian Sea is bordered by Azerbaijan in the west, Turkmenistan in the east, and Iran in the south. The Elburz Mountains (Alborz Mountains) stretch along the southern coast and are snow-covered in this image. Milky-blue and green patches color the waters of the Caspian Sea. These are likely evidence of blooms of phytoplankton. Phytoplankton are small chlorophyll-containing, plant-like organisms that live in oceans, lakes, and seas in small numbers year-round, but when conditions are right can reproduce quickly, creating massive colonies that can be seen from space.