MODIS true color image (bands 1, 4, 3) of the Eastern Mediterranean, 14 January 2005.
Four banks of fog encroach upon the eastern Mediterranean waterfronts of spain, France, and Italy in this true-color Terra MODIS image from January 14, 2004. At bottom left, a bank of fog settles over northeastern Spain south of the Pyrenees. Between the Pyrenees and Massif Central mountains of southeastern France, another bank of fog reaches toward the Golfe du Lion. On the far side of the Massif Central, a bank of fog is caught against the French and Italian Alps along the Rhone River valley. A final bank of fog curves along northern Italy's Po River valley.
Besides the fog, snow and clouds add touches of white to this early-winter scene. Arcing across the upper left corner of the image in a long thin white line is an airplane contrail. Judging by the line's gradual spreading, the plane was probably flying to the northeast across France. Contrails form when hot, humid jet exhaust is expelled into the cold air at high altitudes, typically more than 8 kilometers (5 miles), above the ground. The exhaust freezes directly into ice crystals, forming thin streaks along the path of the jet. The resulting condensation trails only last a few hours.
Text and image courtesy of NASA's MODIS Land Rapid Response Team.