Lowell Observatory

Percival Lowell founded the observatory partly out of a fascination with Mars. He was captivated by the idea that the red planet was crossed by canals built by an intelligent civilization, and he chose Flagstaff's high, dry air and dark skies as an ideal place to study it. Though his canals turned out to be an illusion of the eye and the atmosphere, his choice of site was inspired, and it drew serious astronomy to northern Arizona.

Lowell used his fortune to build a first-rate research station on the mountain, equipping it with a great refracting telescope housed under a wooden dome. His enthusiasm and money gave the observatory its start, and his belief that something waited to be found beyond the known planets would, years after his death, bear remarkable fruit.

Lowell had predicted an undiscovered planet tugging at the orbits of Neptune and Uranus, which he called Planet X, and he searched for it without success. The hunt continued after he died, and in 1930 a young Kansas farm-raised astronomer named Clyde Tombaugh, comparing photographic plates of the sky taken nights apart, spotted a tiny point of light that had moved. It was a new world, and it was named Pluto.

The discovery made headlines around the globe and put Lowell Observatory in the history books. Visitors today can see the telescope and the plate-comparing machine that made it possible, and stand in the dome where a patient search across the winter sky added a ninth body to the solar system, a place of pilgrimage for anyone who has ever looked up and wondered what lies out there.

Lowell Observatory played a part in an even larger discovery. In the early twentieth century the astronomer Vesto Slipher, working here, measured the light of distant spiral nebulae and found that most of them were rushing away from us at enormous speed. His measurements were among the first hard clues that the universe is not static but expanding, a finding that reshaped our whole understanding of the cosmos.

That work, less famous than Pluto but arguably more profound, cemented the observatory's place at the frontier of astronomy. From this pine-topped hill came evidence that would help lead others to the idea of a universe born in a single beginning and growing ever since, a reminder that great discoveries can come from a modest mountaintop far from any city.

The observatory endures in part because Flagstaff has protected the very thing that drew Lowell here: darkness. The city was the first in the world to be named an International Dark Sky City, passing laws to limit light pollution so the stars stay bright overhead, a rare civic commitment that keeps its skies among the finest near any American town.

That heritage makes an evening at Lowell special. On clear nights, staff open the domes and set up telescopes for the public, guiding visitors to the moon, the planets, star clusters, and distant galaxies. Set high in the cool pines above the desert, with the Milky Way arching overhead, it is a place that connects the great discoveries of the past to the simple wonder of looking up at a truly dark sky.

The closest Boutel™ stays, so you can turn this stop into an overnight. Each is a place we chose through independent editorial review, never a paid placement.

Lowell Observatory, perched on a hill above Flagstaff, Arizona, is one of the oldest and most historic observatories in the United States, founded in 1894 by astronomer Percival Lowell. It is famous as the place where Pluto was discovered in 1930, and it remains an active research and public-education center. Flagstaff's status as the world's first International Dark Sky City makes it an ideal spot for stargazing. With historic telescopes, exhibits, tours, and public night-sky viewing, Lowell offers an inspiring journey through astronomy for all ages.

Pluto was discovered at Lowell Observatory in 1930 by a young astronomer named Clyde Tombaugh, working from photographic plates in a systematic search for a distant planet that Percival Lowell had predicted. The telescope and dome used in the discovery are preserved at the observatory, and visitors can see them and learn the story of how the tiny, distant world was found. This landmark achievement is a highlight of a visit and a proud chapter in the history of American astronomy.

Yes, one of the joys of visiting Lowell is the chance to look through telescopes during evening programs, when weather permits, viewing the moon, planets, star clusters, and other celestial objects under Flagstaff's famously dark skies, alongside daytime solar viewing. The observatory offers guided programs, exhibits, and access to historic instruments like the Clark Telescope. Because night-sky viewing depends on clear weather and program schedules, checking the current calendar and hours before you go helps ensure you catch the telescope experiences.

Evening visits are ideal for the signature telescope viewing and stargazing programs, so plan around a clear night if possible, while daytime visits offer tours, exhibits, and solar viewing. Clear, dark nights are best for seeing celestial objects, and the high-elevation Flagstaff climate means chilly evenings even in summer, so bring layers. Checking the program schedule and weather before you go is wise, since night-sky viewing depends on clear skies. Any season can be rewarding with the right conditions.

Lowell Observatory is in Flagstaff, a lively mountain town with historic downtown, Northern Arizona University, and the Riordan Mansion, and a gateway to the volcanic monuments of Sunset Crater and Wupatki, Walnut Canyon's cliff dwellings, and the San Francisco Peaks. The Grand Canyon and Sedona are within reach. That makes Lowell Observatory a highlight of a Flagstaff visit, easily combined with the town's culture, the surrounding national monuments, and the dark-sky stargazing the region is famous for.