In April 1958, Flagstaff, Arizona passed what is generally credited as the world’s first law to protect the night sky. It was modest. It banned advertising searchlights within city limits, with a $300 fine or 90 days in jail for anyone who switched one on. But it set the tone for everything that followed, and on October 24, 2001, the International Dark-Sky Association named Flagstaff the first International Dark Sky City.
That’s the story of stargazing in Arizona. The desert air and the elevation help, of course. What really makes the state special is that astronomers and towns spent decades arguing over streetlights, and the astronomers mostly won.
Flagstaff and Lowell Observatory
Percival Lowell founded his observatory on Mars Hill above Flagstaff in 1894, mostly to study Mars. He was convinced he could see artificial canals on the planet, which turned out to be his eye joining faint features into lines. But the place he built did serious work. Vesto Slipher, who joined in 1901, measured how fast distant galaxies were moving away from us starting in 1912, early evidence of the expanding universe. And on February 18, 1930, Clyde Tombaugh found Pluto there, comparing photographic plates.
Lowell Observatory is still working, and still open to visitors. The 24-inch Clark refractor, built in 1896, is used for public observing, which means you can look through the same telescope that served Lowell’s Mars obsession, well over a century later! The observatory became a National Historic Landmark in 1965.
The Flagstaff sky didn’t stay dark by accident. The Flagstaff Dark Skies Coalition has the long version, and it’s a surprisingly gripping local politics story. In 1988 a proposed trucking yard near the U.S. Naval Observatory station west of town was rejected, and Coconino County followed with a lighting code that restricted both the type and amount of light per acre, a first. The city adopted a nearly identical ordinance in 1989, including a requirement for low-pressure sodium lamps, which glow in two narrow bands of orange and leave the rest of the spectrum clean for telescopes.
Sedona and the Grand Canyon
Sedona learned from its neighbor. Working with residents and local businesses from around 1999, the city passed a new outdoor lighting ordinance in 2001, modeled partly on Flagstaff’s. It later offered matching grants of up to $10,000 to help businesses replace old fixtures, and on August 4, 2014, it became the world’s eighth International Dark Sky Community. The pleasure here is the foreground. Milky Way over red sandstone is hard to beat.
Grand Canyon National Park took longer, because it had a lot of lights to fix. The park won provisional status in 2016, and as part of earning full International Dark Sky Park certification in June 2019, it retrofitted 67 percent of its roughly 5,000 exterior fixtures. Every June it runs a star party on the rim. A canyon a mile deep is a fine place to feel small, and doing it under the Milky Way is a double dose!
Tucson and Kitt Peak
Tucson is, in a sense, the capital of all this. DarkSky International, which started as the International Dark-Sky Association, was founded there in 1988 by David Crawford, a professional astronomer, and Tim Hunter, a physician and amateur astronomer. Tucson and Pima County required low-pressure sodium lighting in 1986, before Flagstaff did.
Southwest of the city, on land leased in perpetuity from the Tohono O’odham Nation, sits Kitt Peak National Observatory. Aden Meinel chose the site in 1958, and it was dedicated in 1960. There are more than twenty optical telescopes and two radio dishes up there at about 2,096 meters. The 4-meter Mayall telescope now carries DESI, an instrument that maps distant galaxies to trace the history of cosmic expansion. The McMath-Pierce solar telescope, a great slanted shaft cut into the mountain, was for decades the largest solar telescope in the world. It’s one of the strangest buildings in American science.
Kitt Peak came close to losing it in June 2022, when the Contreras Fire reached the summit on June 17 and destroyed four non-scientific buildings, including a dormitory. The telescopes survived. The observatory reopened to the public in September 2023.
One honest caveat. Dark sky designations are about lighting policy, not a guarantee of a perfect night. Monsoon season clouds can roll in on summer afternoons, and a bright moon washes out the Milky Way no matter how good the ordinance. Check the moon phase before you go.
If this has you looking up, our roundup of night sky photographs and Olson Kundig’s house with a roof that opens to the stars are good company. And Arizona’s other kind of light, the daytime kind, is in our piece on Antelope Canyon.
