Two photographs snapped from the International Space Station, 13 years apart, show Miami-Dade County glowing in an entirely different palette. The 2012 image shows the county bathed in the familiar amber-orange wash of sodium-vapor streetlights. The 2025 image, taken by NASA astronaut Don Pettit, shows a patchwork of white, blue-white and even purple-tinted LED lighting spread across the same grid.
Pettit, who returned to Earth in April 2025 after 220 days aboard the International Space Station as part of Expedition 71/72, posted the side-by-side photos on X, noting the shift in lighting technology between 2012 and 2025, according to Miami Herald. “The city grid really pops! This LED takeover of city lighting is worldwide,” Pettit wrote. The mission brought his career total to 590 days in space across four spaceflights, and included 13 hours of spacewalks.
Why Miami-Dade Made the Switch
The color change traces back to a 2019 Miami-Dade County Board of County Commissioners ordinance authorizing a multi-phase conversion of obsolete high-pressure sodium streetlights in special taxing districts to energy-efficient LED technology, per county records. The push reflects a broader move by major cities toward LED lighting, which offers instant-on performance, a long service life, resistance to breakage and vibration, a compact size, and reliable performance in cold temperatures.
The U.S. Department of Energy says LED lighting can cut energy costs and has the potential to nearly halve general lighting energy use by 2030, while also improving grid resiliency. LED fixtures also lack the infrared or ultraviolet emissions common in older lighting technology, according to the same federal assessment cited in the seed report.
Miami-Dade's conversion wasn't without hiccups. The county temporarily paused streetlight conversions in June 2019 after residents and local officials complained that new LED fixtures created dark spots between street poles spaced roughly 300 feet apart, according to Florida Bulldog. County staff conducted photometric audits across neighborhoods before retrofits resumed. The scale of the underlying network is considerable: Florida Power & Light partnered with Silver Spring Networks back in 2014 to deploy 75,000 wirelessly connected smart streetlights across Miami-Dade, creating one of North America's largest networked streetlight grids, per Smart Grid News.
The Purple Streetlight Mystery
Not every color shift visible from orbit was intentional. Across Florida and more than 30 U.S. states, numerous white LED streetlights installed between 2017 and 2019 began glowing purple or violet due to a manufacturing defect, in which the yellow silicone-phosphor coating peeled off the underlying blue LED die, according to WKMG ClickOrlando. White LEDs rely on that phosphor coating to convert blue light into the broader visible spectrum, so when it fails, the fixtures skew violet instead of white.
The color of new streetlights also carries a health dimension. The American Medical Association adopted guidance in June 2016 recommending outdoor LED streetlights use a color temperature of 3,000 Kelvin or lower, to limit glare and reduce high-intensity blue light that suppresses melatonin production in humans.
Sea Turtles Add Another Layer of Rules
South Florida's coastline complicates the lighting picture further. Beach-visible coastal lighting emphasizes long-wavelength amber or red LEDs at 560 nanometers or higher to avoid disorienting hatchling sea turtles that rely on natural moonlight and dark horizons to find the ocean.
Monroe County updated its local ordinance in August 2026, eliminating yellow bug lights and requiring certified amber LEDs of at least 560 nanometers for all beach-adjacent exterior fixtures, according to Access Fixtures.
The stakes extend beyond turtle nesting beaches. DarkSky International reported in June 2026 that artificial light at night functions as a widespread environmental pollutant, altering growing seasons, disrupting insect hibernation, and affecting net ecosystem respiration and carbon cycling. Satellite imagery tracking night lights, including astronaut photographs like those Pettit captured, offers a view of nighttime illumination worldwide.
A Regional Pattern
Broward County partnered with Florida Power & Light in February 2026 to upgrade streetlights in Washington Park to storm-resilient LEDs mounted on concrete poles engineered to withstand severe weather. The project pairs lighting upgrades with grid-hardening infrastructure ahead of hurricane season.
Whatever their color, the LED fixtures now scattered across Miami-Dade represent a technological shift that's visible even from low Earth orbit. Pettit's photographs offer a rare vantage point on a change that's been unfolding on the ground, one intersection at a time, since the county's ordinance took effect years ago.
