MIAMI (VINnews) — MIAMI — NASA astronaut Don Pettit says he has spent 23 years documenting from space how cities around the world are replacing traditional yellow-orange lighting with LEDs.

I have spent 23 years documenting the global LED transition of city lighting from space.

Across my 4 missions to the ISS, I have photographed every major city on Earth, building a data set of the gradual replacement of sodium vapor lighting with LEDs.

The warmer, yellow-orange… https://t.co/gNNiEULpkr pic.twitter.com/ChFbj8Jtgs

— Don Pettit (@astro_Pettit) September 7, 2026

In a post Sunday on X, Pettit said he photographed major cities during four missions to the International Space Station, creating what he described as a record of the gradual global shift from sodium-vapor lighting to LEDs.

Pettit said the warmer yellow-orange glow of older gas-discharge lamps has increasingly given way to multicolored LED lighting, citing energy savings and environmental considerations.

The transition has dramatically changed the appearance of cities from orbit, he said, while also affecting how cities look and feel from the ground.

As an example, Pettit highlighted Miami, sharing a 2025 photograph taken from the ISS alongside an earlier view.

“Miami, Florida as seen from the ISS in 2025,” Pettit wrote. He said the city had changed tremendously since his previous mission, with yellow-orange sodium-vapor lights replaced by multicolored LEDs.

“The city grid really pops!” he wrote.

Pettit said the LED transition is occurring worldwide and shared a collection of what he called some of the most striking before-and-after examples he has observed during his missions.

Don Pettit’s X post