Don Pettit documents Earth's changing nighttime lights over 23 years

NASA astronaut Donald Roy Pettit has compiled a visual archive documenting the evolution of Earth's nighttime lighting over a 23-year period. Through four missions to the International Space Station (ISS), Pettit has captured the global transition from traditional sodium vapor lamps, which produced characteristic yellow and orange hues, to more chromatically diverse LED lighting systems.

Pettit began this documentation during Expedition 6 between 2002 and 2003. To overcome the technical challenge of photographing from a station traveling at 28,000 kilometers per hour, he constructed a DIY tracking device known as a ‘barn door tracker’ using available station components. This allowed for longer exposures and sharper images. His recent work, conducted during Expeditions 71 and 72 in September 2024, continues this study by photographing major cities including Paris, Istanbul, Lima, Osaka, Beijing, Casablanca, Riyadh, and Maracaibo.