At night, the Windy City transforms into a city of lights, illuminated by the orange and white hues of the Chicago Metropolitan Area. In this nighttime photo, taken by an astronaut aboard the International Space Station, light-yellow lights illuminate the city’s densely populated downtown area.
The Chicago Harbor and Navy Pier in downtown Chicago extend into Lake Michigan. Warm-hued lights illuminate sprawling roadways like Interstate 90, which stands out as the wide, orange line. The range of colors in nighttime cityscapes worldwide, including Chicago, is often due to the types of lighting used. High-pressure sodium lighting has a much warmer tone than the cooler, blue-to-green-hued light-emitting diodes (LEDs).
Flowing through the city, the Chicago River appears as a slender strip of darkness, running nearly parallel to interstates 55 and 90. The Chicago River connects Lake Michigan barge traffic to neighboring rivers, such as the Des Plaines River, through tributaries and various canal systems. The Des Plaines River appears as a dark feature between the metropolitan area and Chicago O’Hare International Airport. This river is lined with nature preserves, golf courses, and parks, all of which appear dark in this nighttime image. In urban landscapes, city lights outline dark and open areas like the Rosehill Cemetery and Big Marsh Park.
As Chicago expanded in the late 1800s, the city needed a solution to simplify navigation. The city was reorganized into a grid layout, restructuring street names, address numbers, and blocks into north-south and east-west orientations. This grid pattern is made obvious by the nighttime lights of the urban area. The warm-toned lights associated with residential areas contrast with the predominantly white lighting of commercial, industrial, and transportation areas. These land uses typically line highways and are spread across the outskirts of the Chicago area.
Astronaut photograph ISS070-E-105097 was acquired on March 1, 2024, with a Nikon D5 digital camera using a focal length of 400 millimeters. It is provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit, Johnson Space Center. The image was taken by a member of the Expedition 70 crew. The image has been cropped and enhanced to improve contrast, and lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by Sara Schmidt, GeoControl Systems, JETS II Contract at NASA-JSC.
