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Research Observatories

Dan Brocious shares astronomy opportunities for both the casual stargazer and the advanced researcher. Astronomical research is one of Arizona’s most innovative forms of revenue. Astronomy and supporting industries bring an average of 250 million dollars annually to the state, and some of the best known research observatories in the world scan our clear night skies with extraordinary telescopes. In addition to optical telescopes (studying wavelengths of light visible to humans), Arizona’s observatories study radio waves, infrared, and even high energy Gamma rays, all emitted by cosmic bodies.   

Scroll through the tabs at the top of the page or the links below for a tour of our state’s remarkable facilities.

Major Research Observatories

Kitt Peak National Observatory/National Optical Astronomy Observatory: Kitt Peak, home of the Mayall Telescope, boasts more telescopes than any other mountain in the world.

Lowell Observatory: The home of the historic Clark Telescope now boasts a new site with the powerful new Discovery Channel Telescope.

Mount Graham International Observatory: The Large Binocular Telescope is among the world’s most advanced. The Vatican Observatory Research group and Arizona Radio Observatory also operate on this mountain.

U.S. Naval Observatory Flagstaff Station: The US Navy’s dark sky site for optical and near-infrared astronomy.

Whipple Observatory: Home to one of only three arrays for Gamma ray astronomy in the world.

Click on the “Observatories” icon on the Recreation and Cultural Sites Map to find facilities open to the public!Click on the “Observatories” icon on the Recreation and Cultural Sites Map to find facilities open to the public!

Read more! Observatories of the Southwest: A Guide for Curious Skywatchers by Douglass ISbell and Stepher E. Strom is available at the Arizona Experience Store.

Choose Your Star Adventure

Customize a tour of the cosmos with World Wide Telescope! Just click on the image to soar through space to view  actual images of stars, planets, and galaxies.

National Optical Astronomy Observatory/Kitt Peak National Observatory

Kitt Peak telescopes at sunset.National Optical Astronomy Observatory (NOAO) is the national research and development center for ground-based nighttime astronomy in the United States. Its primary goals are research, education, and public outreach. NOAO runs three observatories: Kitt Peak, Cerro Tololo Inter-American Observatory (Chile) and the NOAO System Science Center; and collaborates with a number of others on major projects. Its headquarters are located at the University of Arizona (UA).

NOAO is operated by the Association of Universities for Research in Astronomy (AURA) under cooperative agreement with the National Science Foundation. This collaboration enables the development of the US optical-infrared (O/IR) System, an alliance of public and private observatories.

Kitt Peak National Observatory (KPNO) is a prime example of this collaboration. Kitt Peak is the site of KPNO, NOAO, and hosts the facilities of consortia which operate 25 optical telescopes and two radio telescopes. It is also the site of the National Solar Observatory, which studies the sun. The mountain boasts more research telescopes than any other mountain in the world, and is the most diverse collection of astronomical observatories on Earth for nighttime optical and infrared astronomy and daytime study of the sun.

Location: Kitt Peak, in the Quinlan Mountains in the Tohono O’odham Nation, 56 miles southwest of Tucson.

Outreach: The Kitt Peak Visitor Center is open to the public daily. Enjoy day tours, evening programs, and even astronomy camps. An array of Coronado Solarmax telescopes are installed for public solar viewing.

Notable Achievements
  • Preprocessed emission-line image of the Rosette nebula (NGC2237) taken at the National Science Foundation's 0.9-m telescope on Kitt Peak with the Mosaic camera.Research conducted at Cerro Tololo and supplemented at Kitt Peak offered the first proof of the presence of dark matter in the universe.
  • This observatory set stage for government-university collaborations in astronomy. Excellent facilities for solar astronomy, radio astronomy, and imaging.
  • The BigBOSS experiment uses a spectrograph to study dark energy and redshifts in order to create a partial map of the universe when it was only about 4 billion years old.
  • The observatory advanced understanding of the origin of gamma ray bursts.

Take a virtual tour of the facilities!

National Solar Observatory

The National Solar Observatory (NSO) studies the Sun as an astronomical object and as the dominant external influence on Earth. Priorities are solar research, educational, and public outreach. NSO provides leadership in ground-based solar observing facilities, advances instrumentation, and educates students of all ages.

The McMath-Pierce Solar Telescope

The world's largest solar telescope, with a diameter of 1.6 meters. Housed in a structure nearly 100 feet tall with a shaft that slants two hundred feet to the ground and continues into the mountain for prime focus viewing. This telescope detected water and isotopic helium in the sun. It noticed solar emission lines at 12 microns and created the first high resolution images at 1.6 and 10 microns. It also took the first measurement of Kilogauss magnetic fields outside sunspots.

The Synoptic Optical Long-term Investigations of the Sun (SOLIS) project produces continuous unique observations of the Sun’s magnetic field. Conducted over several decades, these long term studies will provide data fundamental to understanding the solar activity cycle, including how solar energy releases and irradiance (solar flares) affect global change.

Partnership with University of Arizona

Inside the Bok telescope, named for Professor Bart Bok in 1996. UA’s Steward Observatory has an active presence on Kitt Peak through projects and telescopes. The Bok Telescope, the largest telescope operated by the Steward Observatory, is situated on the mountain. The Bok is capable of taking both visible wavelength and infrared observations.

Spacewatch Project: In 1980, by Prof. Tom Gehrels and Dr. Robert S. McMillan of the UA’s Lunar and Planetary Laboratory founded Spacewatch to explore the various populations of small objects in the solar system. Still led by Dr. McMillan, Spacewatch studies the statistics of asteroids and comets in order to investigate the dynamical evolution of the solar system. It is one of three asteroid studies conducted by the UA; the others being the Catalina Sky Survey and the Mount Lemmon Sky Survey.

More Tenants and Telescopes

Tenant: WHAM (Wisconsin H-Alpha Mapper from University of Wisconsin) uses a 1.23-meter Calypso for calibration of software and hardware on the Large Synpotic Survey Telescope (LSST) Project.

Tenant: MDM Observatory, owned and operated by a consortium of five universities: the University of Michigan, Dartmouth College, the Ohio State University, Columbia University, and Ohio University uses the 2.4-meter Hiltner telescope and the 1.3-meter McGraw-Hill telescope.

KPNO Major Telescopes

A new wide-field image of Pickering's Triangle, part of the Cygnus Loop supernova remnant, in the constellation Cygnus, taken with the National Science Foundation's Mayall 4-meter telescope.

Mayall 4-meter telescope

Standing eighteen stories tall and so massive it’s visible from Tucson, over 50 miles away, the Mayall is one of the largest optical telescopes in the world. Used primarily for infrared and faint visible light observations, its CCD Mosaic Camera can produce color images of astronomical objects. The Mayall helped determine the role of dark matter in the universe by observing the rotation curves of distant galaxies and has helped to establish the dynamical structure of elliptical galaxies such as M87 and M49.

3.5-meter WIYN Telescope

The WIYN is one of the best imaging telescopes in the world. Built in 1994, it is the newest telescope on Kitt Peak. The WIYN has contributed important work in researching supernovae in distant galaxies, in understanding the origin of gamma ray bursts, and in the evolution of stars in clusters. Second in size only to the Mayall, it is operated on behalf of the WIYN Consortium, comprised of the University of Wisconsin, Indiana University, Yale University and NOAO.

2.1-meter and Coudé Feed

One of KPNO’s earliest telescopes, used for both imaging and spectroscopy. Coudé Feed Telescope sends light into the high-resolution Coudé spectrograph. This apparatus found indications of the distant clouds of hydrogen gas now known as the Lyman-alpha forest, discovered the first gravitational lens and the first pulsating white dwarf. It also contributed to the first comprehensive study of the binary sequence of solar type stars.


Smallest research telescope operated by KPNO. The CCD Mosaic Imager on this telescope affords a 1 degree field of view, a uniquely powerful combination.

Lowell Observatory

The Lowell Observatory brought astronomy to the Southwest in 1896 with the construction of the Clark Telescope on Mars Hill, west of downtown Flagstaff. It is currently one of the largest privately owned research telescopes in the world, operating on three sites in and outside of Flagstaff. In 2011, TIME magazine named the Observatory one of "The World's 100 Most Important Places. Its latest telescope was completed in 2012.

Location: The original Mars Hill site near downtown Flagstaff houses two historic telescopes and the popular visitors center. The Anderson Mesa, 12-miles southeast of Mars Hill, houses most research telescopes and the USNO’s NPOI instrument. The Discovery Channel Telescope sits in the Happy Jack Dark Sky Site in the Coconino National Forest.

Outreach: The Visitors Center is open daily until 9:30 pm on Monday, Wednesday, Friday, and Saturday, and until 5:00 pm all other days. Enjoy educational camps, a gift shop, extensive exhibits, and special presentations at the site of the historic Clark Telescope.

Notable Achievements
  • First astronomical observatory in Arizona
  • First observation of redshifts and the expanding nature of the universe (1912)
  • Discovery of Pluto (1930)
  • Titan and the Kuiper Belt
  • Exoplanets

Major Telescopes

Mars Hill site

Clark Telescope: Built in 1986 by Percival Lowell. Known as the People’s telescope, it is currently one of the most celebrated public telescopes in the world.

The 0.33-meter (13 in) Abbot L. Lowell Astrograph, also known as the Pluto Discovery Telescope was built by Alvan Clark & Sons in 1929. Clyde Tombaugh discovered Pluto with it in 1930.

Happy Jack Observing Site

Completed in 2012, the Discovery Channel Telescope (DCT) is 5th largest telescope in continental U.S. The 4.3-meter telescope rises seven stories above the top of a cinder cone in the Coconino National Forest. The Ritchey-Chretien (RC) instrument configuration enables Spectroscopic and imaging observations simultaneously! Lowell Observatory and Discovery Communications collaborated to build this $53 million facility.

DCT will look into the Kuiper Belt, beyond the orbit of Neptune to answer fundamental questions about how our solar system formed and how dwarf galaxies evolve.

Anderson Mesa Station

Established in 1959 as a dark sky observing site for Lowell Observatory, the station houses the bulk of Lowell’s research telescopes and is the location of instruments run by the U.S. Naval Observatory Flagstaff Station.

Perkins Telescope

At 1.83-meters (72 in) it is the largest telescope on Anderson Mesa, shared with Boston University (BU) and Georgia State University. Its primary research instrument, the RRISM (Perkins Reimaging System)—is used for wide-field imaging, multi-object spectroscopy, and polarimetry.

John Hall Telescope

This 1.07-meter (42 in) instrument is optimized for CCD imaging, photoelectric photometry, and spectroscopy.

National Undergraduate Research Observatory (NURO)

This .79-meter (31 in) telescope was installed in 1964 at Anderson Mesa by the U.S. Geological Survey (USGS) to study the moon in preparation for the Apollo missions. It was purchased by Lowell in 1972, and refurbished in 1990. A key project is searching for O-type binaries in clusters.

Titan Monitoring Telescope

 Designed and built in house to support research on Titan, Saturn’s largest moon. It is part of the Titan Monitoring Project, a confederation of ground-based telescopes around the world that collect and share data of Titan’s atmospheric and surface conditions.

Mount Graham International Observatory

The LBT, housed in its 120 foot-tall building, opens to the night sky.Mount Graham International Observatory (MGIO) is home to one of the world’s largest and most powerful telescopes: the Large Binocular Telescope, or LBT. A division of the UA Steward Observatory, MGIO is the research arm of the University of Arizona Astronomy Department. The observatory currently operates facilities for three scientific organizations: The Vatican Observatory, the Arizona Radio Observatory (a division of the Steward Observatory), and a consortium of institutions that operate the LBT.

Construction of MGIO began in 1989, with Vatican Advanced Technology Telescope and Heinrich Hertz Submillimeter Telescope beginning operations in 1993.

Location: The observatory is perched on the 10,720-foot Mount Graham, the highest peak in the Pinaleno Mountains, Sky Islands located near Safford in eastern Arizona. Mount Graham is the habitat of the endangered Mount Graham Red Squirrel, a subspecies of the American Red Squirrel. A wildlife refuge surrounds the observatory. Permits are required for all vehicles on the mountain.

Outreach: The visitors center is located at the Discovery Park Campus at Eastern Arizona College in Thatcher. Eastern Arizona College conducts weekend tours starting mid-May and ending mid-November. The tour includes a lecture of Mount Graham’s biodiversity and a picnic lunch as well as a guided tour of the observatory facility. Tourists can explore the stars through the 20-inch Tinsley Cassegrain reflector telescope.

Notable Achievements:
  • The two 8.4-meter mirrors of the LBT represent some of the world’s most advanced optical technology.
  • In 2008 the LBT discovered the galaxy cluster 2XMM J083026+524133, located over 7 billion light years from Earth.
  • The Radio Astronomy Observatory makes some of the most accurate cosmic radio measurement in the world.

Major Telescopes

Large Binocular Telescope

The Large Binocular Telescope (LBT) ranks among the world’s most advanced telescopes. It can image planets outside the solar system and peer back toward the beginning of time.

LBT utilizes some of the most advanced adaptive optics innovations in the world. It utilizes two 8.4 meter mirrors to achieve the viewing power of an 11.8-meter telescope. The second mirror, added in 2010, can change shape up to 1000 times per minute in order to correct for atmospheric distortion.

LBT is owned and operated by a consortium of over 15 institutions. One quarter ownership belongs to Arizona (UA, ASU, and NAU), one quarter belongs to Italy (observatories from five cities), one quarter belongs to Germany, mostly with the Max-Planck Institute, and the remaining 25% is split between Ohio State University and the Research Corporation, comprising  University of Notre Dame, University of Minnesota, University of Virginia, and Ohio State University.

 Vatican Advanced Technology Telescope

The Vatican (yes, the Vatican) is one of the oldest astronomical research institutions in the world. Its headquarters are located at the papal summer residence in Castel Gandolfo, Italy. Its dependent research center, the Vatican Observatory Research Group, is hosted by Steward Observatory and responsible for the 1.8-meter Alice P. Lennon Telescope with its Thomas J. Bannan Astrophysics Facility, known together as the Vatican Advanced Technology Telescope (VATT).

Vatican Advanced Technology Telescope is used primarily for imaging and photometric work. It is noted for observations about how the shape of galaxies has changed over the age of the universe and the discovery of the first binary ‘Vesta chip’ asteroid. VATT has also found Massive Compact Halo Objects in the Andromeda Galaxy.

Heinrich Hertz Submillimeter Telescope (Arizona Radio Observatory)

Telescope domes dot the Anderson Mesa station.The Heinrich Hertz Submillimeter Telescope (SMT) is the most accurate astronomical telescope in the world, designed to operate in the sub-millimeter wavelength region with an accuracy of 14 microns root mean square. Its 10-meter-wide parabolic dish is housed in a building to protect it from inclement weather. The SMT is operated in conjunction with the former National Radio Astronomy Observatory (NRAO) 12-meter Telescope located on Kitt Peak. Combined, the two telescopes routinely cover the entire millimeter and submillimeter windows from about 4.6 mm to about 0.6 mm. However, observations with the SMT can be made all the way to 0.3 mm frequencies.

Arid desert air is vital to the success of signal detection on the SMT, especially for EHF (extremely short wavelength radio). Water vapor or clouds cause electromagnetic waves to lose intensity rapidly. The SMT is often stowed during the summer months because the Monsoon Season brings too much atmospheric moisture.

Arizona Radio Observatory

Arizona Radio Observatory is a division of UA’s Steward Observatory with telescopes on MGIO and Kitt Peak. Radio astronomy is a subfield of astronomy that studies celestial objects at radio frequencies. Celestial objects like stars and galaxies emit waves of many frequencies and energies. In addition to visible light waves, radio waves, infrared waves, and even Gamma rays can be detected by different types of telescopes. Radio galaxies, quasars, pulsars, and masers commonly emit radio waves and microwaves which have a lower energy and a longer wavelength than the visible spectrum. Radio astronomy discovered cosmic microwave background radiation, which provided compelling evidence for the big bang theory.      

The Submillimeter Telescope at MGIO studies the structure and dynamics of late-type stars (with surface temperature cooler than that of our Sun), star formation, and planetary nebulae, with a healthy dose of astrochemistry.

US Naval Observatory (USNO) Flagstaff Station

Established in 1955 a few miles west of Flagstaff, Arizona, the Flagstaff station is the US Naval Observatory's dark-sky site for optical and near-infrared astronomy. There are presently two USNO sites in the Flagstaff area: the station (NOFS) and the Navy Prototype Optical Interferometer (NPOI), located some 15 miles south of the city at Anderson Mesa.

NOFS was established in 1955. The idea of relocation had been considered several times since 1947, both for political reasons and to escape the light pollution of Washington D.C. In the 1940s John Hall was conducting breakthrough research on interstellar polarization with the 40-inch Ritchey-Chretien telescope, a telescope with an unproven design but which delivered unprecedented results. As light pollution grew around Washington D.C., Hall himself selected the Anderson Mesa for its excellent viewing and moved the instrument there in 1955 on two flatbed trucks.

By 1956, Hall and another astronomer, Kai Strand, won funding for a 1.55 meter astrometric telescope. In the following years, Flagstaff Station established itself as an astrometric power spot, and was long involved in the timekeeping measurements that ensured the accuracy of the Naval atomic clock. Astrometric research and calibration still occurs with the Flagstaff Station instruments.

Location: NOFS facilities are located just west of Flagstaff, at 10391 Observatory Road. NPOI is located at the Anderson Mesa in the Coconino National Forest.

Outreach: The USFS does not have a regular public program, but school groups and other educational tours may be coordinated by appointment during the day. The USFS hosts an open house every year during the Flagstaff Festival of Science.

Notable Achievements

Major Telescopes

NPOI (Navy Precision Optical Interferometer) is a facility of USNO with a specialized astronomical telescope called an interferometer. NPOI can record images of stars and optically separate distant pairs of stars so close together that they appear as a single star in even the largest conventional telescopes. Their unique array of six mirrors spaced tens of meters apart (rather than a single telescope) creates images of intense detail. 

Lowell operates the NPOI under contract from the USNO. The instrument is a collaboration of Lowell Observatory, the U.S. Naval Observatory Flagstaff Station (NOFS), and the U.S. Naval Research Laboratory (NRL). The first images were acquired in 1996.

Kai Strand Astrometric Reflector

The largest optical telescope operated by the U.S. Navy, this 1.55-meter telescope produces extremely accurate astrometric measurements in small fields. Over 1,000 of the world's most accurate stellar distances and proper motions have been measured with this telescope since 1964.

1.3-meter reflector

This unnamed newest telescope at the Flagstaff Station was completed in 1999. The telescope is a modified Ritchey-Chretien optical design which can produce a very large, well-corrected field.

Ritchey-Chretien Reflector

This 1.0-meter telescope, completed in 1934, is the largest and last Ritchey-Chretien telescope designed and built by George W. Ritchey and used in the pioneering work on the polarization of starlight. Originally located at the main Naval Observatory in Washington, D.C., increasingly bright urban skies led to its relocation to Flagstaff and the establishment of the Flagstaff Station in 1955.


Flagstaff Astrometric Scanning Transit Telescope (FASTT) is a completely automated transit telescope. This 0.2-meter (8-inch) instrument uses scan-mode CCD cameras to measure the positions of hundreds of thousands of stars

The Pinwheel Galaxy, also known as Messier 101 and NGC 5457, is a face-on spiral in the constellation Ursa Major.

The Pinwheel Galaxy, also known as Messier 101 and NGC 5457, is a face-on spiral in the constellation Ursa Major. Find more images at http://www.sdss3.org/.

Tour the NPOI!

How does NPOI work? Click on the image to begin a virtual tour of the instrument.

Fred Lawrence Whipple Observatory

Mosaic image of the Crab Nebula by the Hubble Space Telescope.The Fred Lawrence Whipple Observatory is the largest field installation of the Smithsonian Astrophysical Observatory (SAO) outside of their main site in Cambridge, Massachusetts. Owned and operated by the SAO, it enjoys a number of research collaborations. The MMT (Multiple Mirror Telescope) Observatory, housing a 6.5-meter telescope, is jointly run by the SAO and the University of Arizona.

Roadwork to the site then known as the Mount Hopkins Observatory began in 1966; the 10-meter gamma-ray telescope was constructed in 1968.

Location: Mount Hopkins in the Santa Rita Mountains,  a Sky Island range approximately 35 miles south of Tucson near Amado.

Outreach: Open Monday–Friday, the visitors center offers exhibits on old telescopes, galaxy distribution, and the history of the optical telescope. Select exhibits come with a full text bilingual guide. Visitors can also gain an understanding of gamma ray astronomy: what it is and where it is going.

Notable Achievements

Gamma Ray and Cosmic Ray Astronomy. The observatory is known for pioneering work in ground-based gamma-ray astronomy through the development of the Imaging Atmospheric Cherenkov Technique (IACT) with the Whipple 10-meter Telescope during the early 1980s.

In the late 1980s, the 10-meter reflector detected a Gamma ray source in the Crab Nebula. Further research determined that it was coming from a pulsar (a dead neutron star that exploded in a supernova almost one thousand years ago, in 1054). The observations led to insight about the properties, emissions, and magnetic fields of collapsed stars.

Major Telescopes

Learn how the VERITAS array houses several unusual telescopes that search for bursts of light that indicate gamma rays crashing into Earth’s atmosphere.


This array is comprised of four 12-meter reflectors for gamma-ray astronomy in the 50GeV-50TeV energy range. It is one of only three IACT (Imaging Atmospheric Cherenkov Telescopes) systems operating in the world today.

PAIRITEL (Peters Automated IR Imaging Telescope; ex-2MASS)

1.3-meter (51-inch) reflector, for infrared observations, especially of gamma-ray burst afterglows, supernovae and other variable sources.

10-meter Reflector

Used for gamma-ray astronomy in the 100GeV-10TeV energy range.

Multiple Mirror Telescope MMT

The 6.5-meter (256-inch) MMT at the MMT Observatory, a joint facility operated with the University of Arizona, researches solar system, galactic and extragalactic astronomy.


1.5-meter (60-inch) and 1.2-meter (48-inch) reflector telescopes, for solar system, galactic and extragalactic astronomy.

Hungarian Automated Telescope (HAT)

HAT is a  network of optical refractor telescopes used for robotic searches for variable stars and exoplanets.

MEarth Array

Eight independent 40-centimeter optical reflector telescopes, used for robotic searches for exoplanets and M-dwarf stars.

Information courtesy of the Fred Lawrence Whipple Observatory.

What is Gamma Ray Astronomy?

Gamma rays are relatively rare waves of very high energy photons. A Gamma ray has an energy of at least 100 KeV (kiloelectronvolts), though cosmic Gamma rays can be as high as 10 TeV (ten billion KeV). The high energy of gamma rays makes them biologically hazardous. Only radioactive decay (radiation) and very high energy reactions like lightning strikes produce Gamma rays here on Earth. Gamma rays also occur from a number of cosmic processes.

Supernova explosions, solar flares, interactions between cosmic rays and interstellar gas, and interactions between energetic electrons and magnetic fields all produce Gamma rays. Therefore, when Gamma rays from space are detected, they are a likely indicator of cosmic activity, such as the formation of an exoplanet or the death of a star. Earth’s atmosphere absorbs most of the energy from Gamma rays, so a special technique was developed to search for them.

The Cherenkov technique, or IACT (Imaging Atmospheric Cherenkov Technique) uses Earth’s atmosphere as a Gamma ray detection medium. Telescopes search a collection area of many hundreds of square meters looking for short, bright bursts of light created when a Gamma ray collides with the Earth’s atmosphere and produces charged particles known as Cherenkov radiation. Usually, an instrument with a large segmented mirror reflects the light onto an array of photomultiplier tubes that feed electronic arrays to record and digitize the pattern of activity.