Harquahala Peak Observatory

High on Harquahala Peak near Wenden, Arizona, the Harquahala Peak Observatory is a weathered adobe building that once played a role in early American astrophysics. Built by the Smithsonian Institution in 1920, it spent five years measuring the strength of the sun.

About Harquahala Peak Observatory

The observatory is a two-story adobe building with wooden beams, a corrugated tin roof and siding, and a wooden second-story porch, standing at 5,680 feet (1,730 m) elevation in La Paz County, Arizona. A cement water catchment device sits at its northern end. The site, together with a small storage shed and 10 acres of land, was listed on the National Register of Historic Places in 1975.

History

The Smithsonian Institution built the observatory and an accompanying storage shed in 1920, choosing Harquahala Peak for its remoteness from pollution and its high number of cloudless days. Scientists staffed the site from 1920 to 1925, beginning solar observations on 3 October 1920. Using a pyrheliometer, they measured the solar constant, the strength of the sun's energy reaching Earth, as part of a study into its effect on the planet's climate; the five-year project combined data from Harquahala Peak with a companion station at Mt. Montezuma. Though the solar-constant method was later abandoned and the weather-forecasting results proved inconclusive, the study helped show that the sun's energy reaching Earth's surface was constant. In 1925 the observatory's work moved to Table Mountain, California, for easier access and better atmospheric conditions. Harquahala Peak Observatory is now recognised as a significant early site in the development of American astrophysics.

Location & getting there

The observatory sits within the Harquahala Mountains Wilderness in La Paz County, Arizona, overlooking semi-arid plains, west-southwest of Wickenburg and east of Wenden, off U.S. Route 60. It is now owned by the Bureau of Land Management.

Visiting Harquahala Peak Observatory

The observatory buildings are much deteriorated and the site sits in a remote wilderness area. Check current Bureau of Land Management guidance before planning a visit to the peak.

See your named star from here

A century ago, scientists here pointed instruments at the sun to measure its output; the same principle of precise sky-pointing lets any location be aimed at the right ascension and declination of a star named through Star Register. Find your star's coordinates in the catalogue.