jetcloud

Visible Earth - Contrail Web over the Central Rhne Valley, Eastern FranceThis digital photograph taken through the windows of the International Space Station on May 15, 2002, shows condensation trails over the Rhône Valley in the region west of Lyon. Condensation trails—or contrails—are straight lines of ice crystals that form in the wake of jet liners where air temperatures at altitude are lower than about ?40°C.