The longest river in Europe, the Volga River, was wide with springtime runoff on May 11, 2005, when the Moderate Resolution Imaging Spectroradiometer (MODIS) captured the left image. On April 14, right, the lower reaches of the river formed a thin dark line before emptying into the Caspian Sea. In the next month, melting snow had pushed the river into a wide black ribbon. The images are false color, so that water is black and dark blue, clouds are white and light blue, vegetation is green, bare earth is tan and pink, and snow is light blue. The snow that dusted the northern reaches of the landscape on April 14 had melted by May 11, undoubtedly contributing to the high water along the river.
The large images provided above have a resolution of 250 meters per pixel, but are available in additional resolutions from the MODIS Rapid Response Team.
NASA image courtesy the MODIS Rapid Response Team at NASA GSFC.