Mount Lemmon Observatory is a University of Arizona observatory located in the Santa Catalina Mountains. It operates seven telescopes, and current important projects include the Catalina Sky Survey.
Mount Lemmon has an important place in the history of the American military and civilian space programs. Mount Lemmon radar towers tracked important test missiles launched from White Sands and from Vandenburg Air Force Base. During the Cold War, the site was used as the command centre for Titan II nuclear missiles based near Tucson, and as a radar surveillance site for NORAD (the North American Aerospace Defense Command, based at Cheyenne Mountain, Colorado).
Subsequently, the government gave the site to the University of Arizona, which converted it into an astronomical research facility. The Mount Lemmon Observatory has seven telescopes, including a five-foot telescope. One telescope is a robotic device, now being remotely operated by researchers in South Korea. A second robotic telescope is also slated for construction. That device will be used to search the skies for near-Earth asteroids, a vital priority operation intended to spot any threatening asteroids as far in advance of impact as possible.
Currently, the major project at Mount Lemmon Observatory is another near-Earth object program, called the Catalina Sky Survey. The survey began in the late 1990s after NASA’s Near-Earth Objects (NEO) Observation Program was ordered to identify at least 90% of nearby asteroids at least 1 kilometre (0.6 miles) in diameter, asteroids large enough to cause regional or global destruction in the event of an impact. In addition to reducing the risk posed by future impacts (none of which have been forecast at present), this has also led to numerous discoveries about the composition and orbital dynamics of asteroids in the inner solar system and the inner parts of the Asteroid Belt.
In addition to the large Mount Lemmon telescope, the Catalina survey also makes use of a smaller telescope at nearby Mount Bigelow, and of the Siding Spring Observatory in Australia, charged with covering areas of the sky not visible from Arizona. The Australian telescope is also partly funded by the University of Arizona, and its contribution to the project is sometimes referred to separately as the Siding Spring Survey.
Mount Lemmon Observatory also holds programs for the public. These include an annual summer science camp, called Astronomy Camp, which introduces young visitors to the telescopes and to the basics of astronomical research. Several week-long camps run in June, and there are young adult camps in April and September.