The Kitt Peak National Observatory (KPNO) is a United States

astronomical Astronomy is a natural science that studies celestial objects and the phenomena that occur in the cosmos. It uses mathematics, physics, and chemistry in order to explain their origin and their overall evolution. Objects of interest include ...

observatory An observatory is a location used for observing terrestrial, marine, or celestial events. Astronomy, climatology/meteorology, geophysics, oceanography and volcanology are examples of disciplines for which observatories have been constructed. Th ...

located on

Kitt Peak Kitt Peak () is a mountain in the U.S. state of Arizona, and at is the highest point in the Quinlan Mountains. It is the location of the Kitt Peak National Observatory. The radio telescope at the observatory is one of ten dishes comprising the ...

of the Quinlan Mountains in the

Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

Sonoran Desert The Sonoran Desert () is a hot desert and ecoregion in North America that covers the northwestern Mexican states of Sonora, Baja California, and Baja California Sur, as well as part of the Southwestern United States (in Arizona and California). It ...

on the Tohono Oʼodham Nation, west-southwest of

Tucson, Arizona Tucson (; ; ) is a city in Pima County, Arizona, United States, and its county seat. It is the second-most populous city in Arizona, behind Phoenix, Arizona, Phoenix, with a population of 542,630 in the 2020 United States census. The Tucson ...

. With more than twenty optical and two

radio telescopes A radio telescope is a specialized antenna (radio), antenna and radio receiver used to detect radio waves from astronomical radio sources in the sky. Radio telescopes are the main observing instrument used in radio astronomy, which studies the r ...

, it is one of the largest gatherings of astronomical instruments in the Earth's northern hemisphere. Kitt Peak National Observatory was founded in 1958. It is home to what was the largest solar telescope in the world, and many large astronomical telescopes of the late 20th century in the United States. The observatory was administered by the National Optical Astronomy Observatory (NOAO) from the early 1980s until 2019, after which it was overseen by

NOIRLab The National Optical-Infrared Astronomy Research Laboratory (NOIRLab) is the United States' national facility for ground-based, night-time optical and infrared astronomy. It is funded by the National Science Foundation (NSF) and operated by the ...

. In June 2022, the Contreras Fire led to the evacuation of Kitt Peak. The fire reached the summit at 2 a.m. on Friday, June 17. Four non-scientific buildings, including a dormitory, were lost in the fire. 15 months later in September 2023, the observatory reopened to the public.

General information

was selected by its first director, Aden B. Meinel, in 1958 as the site for a national observatory under contract with the

National Science Foundation The U.S. National Science Foundation (NSF) is an Independent agencies of the United States government#Examples of independent agencies, independent agency of the Federal government of the United States, United States federal government that su ...

(NSF) and was administered by the

Association of Universities for Research in Astronomy The Association of Universities for Research in Astronomy (AURA) is a consortium of universities and other institutions that operates astronomical observatories and telescopes. Founded October 10, 1957, with the encouragement of the National Sc ...

. The land was leased from the

Tohono Oʼodham The Tohono Oʼodham ( , ) are a Indigenous peoples of the Americas, Native American people of the Sonoran Desert, residing primarily in the U.S. state of Arizona and the northern Mexican state of Sonora. The United States federally recognized t ...

under a perpetual agreement. The second director (1960 to 1971) was Nicholas U. Mayall. In 1982, NOAO was formed to consolidate the management of three optical observatories — Kitt Peak; the

National Solar Observatory The National Solar Observatory (NSO) is a United States federally funded research and development center to advance the knowledge of the physics of the Sun. NSO studies the Sun both as an astronomical object and as the dominant external influen ...

facilities at Kitt Peak and Sacramento Peak,

New Mexico New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...

; and the

Cerro Tololo Inter-American Observatory The Cerro Tololo Inter-American Observatory (CTIO) is an Astronomy, astronomical observatory located on the summit of Mt. Cerro Tololo in the Coquimbo Region of northern Chile, with additional facilities located on Mt. Cerro Pachón about to th ...

Chile Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...

. The observatory sites are under lease from the Tohono O'odham Nation at the amount of a quarter dollar per acre yearly, which was overwhelmingly approved by the Council in the 1950s. In 2005, the Tohono O'odham Nation brought suit against the National Science Foundation to stop further construction of gamma ray detectors in the Gardens of the Sacred Tohono O'odham Spirit I'itoi, which are just below the summit. The largest optical instruments at KPNO are the Mayall 4 meter telescope and the WIYN 3.5-meter telescope; there are also several two- and one-meter class telescopes. The

McMath–Pierce solar telescope McMath–Pierce solar telescope is a 1.6 m F-number, f/54 reflecting telescope, reflecting solar telescope at Kitt Peak National Observatory in Arizona, United States. Built in 1962, the building was designed by American architect Myron Goldsmith ...

was for many decades the largest

solar telescope A solar telescope or a solar observatory is a special-purpose telescope used to observe the Sun. Solar telescopes usually detect light with wavelengths in, or not far outside, the visible spectrum. Obsolete names for Sun telescopes include helio ...

in the world and the largest unobstructed reflector (no secondary mirror in the path of incoming light). The ARO 12m Radio Telescope is also at the location. Kitt Peak is famous for hosting the first telescope (an old 91 cm reflector) used to search for

near-Earth asteroid A near-Earth object (NEO) is any small Solar System body orbiting the Sun whose closest approach to the Sun (perihelion) is less than 1.3 times the Earth–Sun distance (astronomical unit, AU). This definition applies to the object's orbit aro ...

s, and calculating the probability of an impact with

planet Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all of Earth's water is ...

. Kitt Peak hosts an array of programs for the public to take part in, including: * Daytime tours, speaking about the history of the observatory as well as touring a major research telescope. * The Nightly Observing Program (NOP), which allows visitors to arrive in the late afternoon, watch the sunset, and use binoculars and telescopes to view the cosmos. * Additionally, there is the Overnight Telescope Observing Program (OTOP). This program allows for a one-on-one, full night of observing using any of the visitor center's telescopes. Guests may choose to do

DSLR A digital single-lens reflex camera (digital SLR or DSLR) is a digital camera that combines the optics and mechanisms of a single-lens reflex camera with a solid-state image sensor and digitally records the images from the sensor. The reflex des ...

imaging, CCD imaging, or simply take in the sights with their eye to the telescope. Iotw2314a - The Belt of Venus over the McMath-Pierce Solar Telescope

Iotw2314a - The Belt of Venus over the McMath-Pierce Solar Telescope

Kitt Peak's Southeastern Association for Research and Astronomy (SARA) Telescope was featured in the WIPB-PBS documentary, "Seeing Stars in Indiana". The project followed SARA astronomers from Ball State University to the observatory and featured time-lapse images from various points around Kitt Peak. A major project started in the 2010s is the Dark Energy Spectroscopic Instrument (DESI) for the 4-meter Mayall telescope, for conducting spectrographic

astronomical survey An astronomical survey is a general celestial cartography, map or astrophotography, image of a region of the sky (or of the whole sky) that lacks a specific observational target. Alternatively, an astronomical survey may comprise a set of image ...

s of distant

galaxies A galaxy is a system of stars, stellar remnants, interstellar gas, dust, and dark matter bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar Sys ...

probing the expansion history of the universe and the mysterious physics of

dark energy In physical cosmology and astronomy, dark energy is a proposed form of energy that affects the universe on the largest scales. Its primary effect is to drive the accelerating expansion of the universe. It also slows the rate of structure format ...

History

The Kitt Peak National Observatory of the United States was dedicated on March 16, 1960. At the dedication a 36-inch telescope and various facilities were ready. Construction was underway for the then planned 84 inch telescope. (i.e. the KPNO 2.1 meter) The 84 inch (2.1 m) had its first light in September 1964. Over the decades the mountaintop hosted many telescopes, and achieved a variety of discoveries. Some examples of astronomical research KPNO contributed to include the study of

dark matter In astronomy, dark matter is an invisible and hypothetical form of matter that does not interact with light or other electromagnetic radiation. Dark matter is implied by gravity, gravitational effects that cannot be explained by general relat ...

, cosmic distances, high-redshift galaxies, and the

Boötes Void file:boovoid.png, 259x259px, A map of the Boötes Void The Boötes Void ( ) (colloquially referred to as the Great Nothing) is a roughly Sphere, spherical region of Interstellar medium, space in the vicinity of the constellation Boötes. It contain ...

. In addition, the observatory has engaged in variety of public outreach and education programs. In 2018, KPNO established plans for its ''Windows on the Universe Center for Astronomy Outreach.''

Notable discoveries

DESI Installed on the Mayall 4-meter Telescope

In 1976 the Mayall Telescope was used to discover

methane Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The abundance of methane on Earth makes ...

ice on

Pluto Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of Trans-Neptunian object, bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the Su ...

. The 90 cm Spacewatch telescope was used to discover the

Kuiper belt The Kuiper belt ( ) is a circumstellar disc in the outer Solar System, extending from the orbit of Neptune at 30 astronomical units (AU) to approximately 50 AU from the Sun. It is similar to the asteroid belt, but is far larger—20 times ...

body,

20000 Varuna 20000 Varuna (provisional designation ) is a large trans-Neptunian object in the Kuiper belt. It was discovered in November 2000 by American astronomer Robert McMillan during a Spacewatch survey at the Kitt Peak National Observatory. It is na ...

in the year 2000. This was discovered by an astronomer noticing the slow moving object in a blink comparison.

Climate

Due to its high elevation, the observatory experiences a

subtropical highland climate An oceanic climate, also known as a marine climate or maritime climate, is the temperate climate sub-type in Köppen classification represented as ''Cfb'', typical of west coasts in higher middle latitudes of continents, generally featuring c ...

( Cfb) with a much cooler and wetter climate throughout the year than most of the

Facilities

Image:Kitt Peak National Observatory - 380° panorama taken from behind the Warner & Swasey Observatory.jpg, 380° panorama of Kitt Peak from the Warner and Swasey Observatory Image:Kitt Peak National Observatory - 400° panorama taken from the Mayall 4-meter observatory.jpg, 400° panorama from Kitt Peak's Mayall 4-meter Observatory

References

External links

Kitt Peak National Observatory Visitor Center
– visiting and tour information
Kitt Peak Webcam

Forecasts of observing conditions
NOAA general forecast for KPNO

NOAA detailed forecast for KPNO

{{Authority control Astronomical observatories in Arizona Buildings and structures in Pima County, Arizona Minor-planet discovering observatories Museums in Pima County, Arizona National Science Foundation Science museums in Arizona Sonoran Desert Tohono O'odham Nation University of Arizona Tourist attractions in Pima County, Arizona NOIRLab 1958 establishments in Arizona Scientific organizations established in 1958