1956 to 1969:  Fighting the Cold War at the Mt. Lemmon Summit

When darkness falls on Mt. Lemmon these days, telescopes observe the skies for nebulae, stars and other exotic objects and the Catalina Sky Survey scans for possible incoming asteroids. During the Cold War, the US Air Force (USAF) scanned the skies for incoming enemy missiles and enemy planes.

The Mt. Lemmon site was one of about 200 sites along the US coastlines and borders. Its instruments scanned for bombers coming down the Pacific coast and north from Mexico.  Three high-power, long-range radar sets were used at “the world’s highest continuously operated radar station" from 1956 through 1969.

In addition to the towers, the 20-acre site hosted barracks, a dining hall, library, hobby shop, small gym, weight-lifting room and a two-lane bowling alley with automatic pinsetters. The Army used a tower for its own radar but it too is gone leaving only a small robotic USAF radio site outside the main gate.

About eighty people worked at the summit, most housed at the facility. A few lived in the valley and would bus up. During winters the snow can close the site so USAF plans called for daytimers to stay up if snow was in the forecast.

During the Vietnam War, the site closed due to budget cuts. Today approximately 200 radar sites operate around the nation, some in their old radar locations.

1970 - Present: New Scanning Opportunities – Steward Observatory Field Station

Since 1970 Steward Observatory has operated astronomical facilities on Mt. Lemmon and Mt. Bigelow that have participated in the birth of infrared astronomy, the survey of the Moon for Apollo lunar landings and the search for near-Earth asteroids. The 61-inch telescope, the largest in the Catalina mountains, is operated by Steward Observatory and was built in the early 1960s to survey the Moon in preparation for the upcoming lunar spacecraft missions. Sky & Telescope called the Atlas of the Moon thus produced "the finest ground-based photographic lunar survey ever done".

Following on the groundbreaking infrared work at Mt. Lemmon, today the University of Minnesota continues to operate the Mt. Lemmon Observing Facility (MLOF), a 60 inch, f/15, infrared-optimized, Cassegrain (Dahl-Kirkham) telescope, which opened in December 1970. The University of Minnesota uses the 60-inch primarily to support observations at national facilities (Chandra, Gemini, NASA IRTF, Spitzer) and long-term monitoring of transient objects (typically comets and classical novae).

The Catalina Sky Survey of the University of Arizona’s Lunar and Planetary Lab detects asteroids - especially those near-Earth bodies that are potentially hazardous to us! This telescope scans over 800 square degrees of sky and detects well over 1,000 asteroids every night. The telescope is the second largest of its kind in the United States.

The Steward Observatory Field station hosts a total of nine research and educational telescopes at the Mt. Lemmon summit and at Mt. Bigelow:

At Mt. Lemmon summit

  • 20-inch Korea Astronomy and Space Science Institute (KASI)
  • 24-inch Phillips (Steward Observatory)
  • 24-inch Manner (University of Louisville)
  • 32-inch Schulman (Steward Observatory)
  • 40-inch (Steward Observatory)
  • 40-inch Korea Astronomy and Space Science Institute (KASI)
  • 50-inch University of Florida
  • 60-inch (Steward Observatory/Catalina Sky Survey)
  • 60-inch (University of Minnesota)

At Mt. Bigelow

  • 61-inch (Steward Observatory)
  • 30-inch Schmidt (Steward Observatory/ Catalina Sky Survey)

US Forest Service

The Steward Observatory Field Station operates in the Coronado National Forest under a permit from the US Forest Service (USFS). This permit has covered the use of the facility for research purposes and astronomy camps, for which it has been used since the 1970s. USFS amended this permit to include the MLSC educational activities – additional camps, public observing, and others. USFS permits operation of the facilities for educational purposes without a fee. MLSC is committed to continuing this excellent partnership with possible expansion of activities in Sabino Canyon.

2008 – Present: Bringing Education into Focus

For over twenty years, Don McCarthy has run his unique Astronomy Camps on Mt. Lemmon. Seeing the opportunities for spectacular educational opportunities, Dr. McCarthy created camps for children and adults who want to engage in the vigorous exploration of the Universe while experiencing the special camaraderie that arises during a camp adventure.

In 2008 Adam Block and the University of Arizona College of Science launched the Mt. Lemmon SkyCenter at Steward Observatory’s Field Station. This initiative presents a new vision for public-university partnering: accessibility, interaction, leadership, and collaborative learning. The mission of the Mt. Lemmon SkyCenter is to engage people of all ages in the process of interdisciplinary scientific exploration at research facilities in the Sky Island environment to foster a deeper understanding of our Earth and our place within the Universe. SkyCenter presents various educational activities including a public evening observing program, summer Sky Island programs, workshops, camps, remote observing, and special educational events. The Mt Lemmon SkyCenter is part of College of Science efforts to integrate public outreach efforts across venues such as SkyCenter and Biosphere 2 to present innovative new learning experiences.