Astronaut Captures Chicago and Detroit Glowing Before Dawn From Space

An astronaut aboard the International Space Station photographed the central and eastern United States in the dark hours before sunrise on Oct. 18, 2026. The image shows cities and highways glowing beneath a thin band of colored light on the horizon, according to NASA's Earth Observatory.

Beyond its beauty, NASA says such pictures have scientific value. Researchers use them to track how the built environment changes, from the growth of cities to shifts in the type of lighting they use.

What does the photo show?

NASA said clear skies over much of the eastern U.S. gave the astronaut an opening to take a wide-angle shot at 4:54 a.m. Central Daylight Time. The photo was taken with a Nikon Z9 camera and a 14-millimeter focal length.

The largest Midwestern metro areas, including Chicago and Detroit, are among the brightest features. Mid-sized cities such as Indianapolis, Cincinnati and Louisville also stand out, along with the state and interstate highways that link them.

What is the green and orange band on the horizon?

According to NASA, the diffuse layer of green and orange visible to the left is airglow. It forms when sunlight strikes atoms and molecules in the upper atmosphere and causes them to emit photons of light.

On the right side of the frame, light from the Sun arcs across the horizon. NASA said sunrise was about an hour away on the East Coast and about two hours away in Chicago.

How do scientists use photos of city lights?

NASA said astronaut photos and other remote sensing observations of nighttime lights help scientists follow changes in the built environment. In the wide view, Chicago's lights look like a uniform pale yellow. In more detailed photos, a range of colors appears, reflecting different types of lighting.

Using NASA's Gateway to Astronaut Photography of Earth archive, researchers have developed a method to tell lighting types apart within the pixels of nighttime photos. NASA said that systematically measuring the brightness, color and extent of urban lights can show how cities grow and evolve.

The agency's credits list a second, more detailed photo, taken on March 1, 2024, by the Expedition 70 crew. It used a Nikon D5 camera with a 400-millimeter focal length. The newer photo was taken by the Expedition 75 crew.

What do satellites add to the picture?

Satellites also watch for changes in lighting. NASA's Black Marble suite of nighttime lights products uses satellite observations to produce science-quality records of nighttime lights worldwide. The records are available at daily, monthly and yearly time scales.

In the eastern U.S., NASA said, scientists have used these data to follow a range of changes:

• power outages and restoration after major storms
• lighting changes tied to new infrastructure
• transitions from older lighting to LED lighting

Why does it matter for everyday readers?

Nighttime lights are a visible sign of how people use and build up the landscape. According to NASA, records of them can show where power was lost after a storm and how it came back, and how lighting changes as cities add infrastructure or switch to LEDs.

The photos themselves are public. NASA said the International Space Station Program, through the ISS National Lab, supports astronauts in taking pictures of Earth that will be of the greatest value to scientists and the public. The images are made freely available online. Additional photos by astronauts and cosmonauts can be browsed in the NASA/JSC Gateway to Astronaut Photography of Earth.

NASA noted that the images shown were cropped and enhanced to improve contrast, and that lens artifacts were removed. The photos are provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit at NASA Johnson Space Center.

Around Prague, based on reporting by NASA