Greater Chicago Metropolitan Area
ISS030-E-062540 (2 Feb. 2012) --- This nighttime image, photographed by one of the members of the Expedition 30 crew from the International Space Station, features the Greater Chicago Metropolitan Area strung along the southwest shore of Lake Michigan. The region is partially covered by clouds, probably low-hanging, or even fog. Meteorologists say there is a fine line between low thin clouds and fog. Fog is not common in the Great Lakes area this time of the year (usually too windy), but this has been an exceptionally mild winter. The faint gold line of airglow—caused by ultraviolet radiation exciting the gas molecules in the upper atmosphere—parallels the horizon or Earth limb. Minor auroral activity (Borealis) is visible in upper right.