This image shows a great white expanse on the surface of Earth, but it's not snow or super-fine sand: in fact, it's a dried up salt lake in Turkey called Lake Tersakan—and satellites even use it as a calibration tool.

The second biggest lake in Turkey and one of the largest saline lakes in the world, Lake Tersakan dries up completely in the summer months to reveal a thick layer of salt. The resulting surface is so bright and white that Earth-observing satellites use it to calibrate their sensors for the color white, in much the same way you adjust the white balance on your camera. The image, provided by the European Space Agency, was captured by Japan’s Advanced Land Observing Satellite (ALOS) using its Advanced Visible and Near Infrared Radiometer type-2 instrument. [ESA]