Contrails Over English Channel
February 5, 2004
Thin streaky clouds called contrails crisscross the English Channel like a tangled spiderweb in this true-color Terra MODIS image from December 9, 2003. Contrails are formed in the wake of airplanes; very small airborne particles emitted in airplane exhaust attract water particles, acting as seeds for clouds (or cloud condensation nuclei, as they are scientifically named). Contrails can be found over most of the planet, and they play a major factor in weather creation. But they only form when airplanes emit the tiny airborne particles into a clean, relatively stable, and very humid air-mass. Continued accumulation forms the thin, streaky clouds pictured here. As the contrails age, they grow more and more indistinct, such as those in the lower left corner of the image.