This mountaintop observatory is painting the largest 3D picture of the universe

Author | Wang Qing

Review | Ding Yi, Zhao Jingyuan

Editor | Zhao Jingyuan

Kitt Peak Observatory at night. Image credit: NOIRLab

Kitt Peak Observatory is located on Kitt Peak in the Quinlan Mountains, about 90 kilometers west of Tucson, Arizona, USA, at an altitude of about 2,096 meters. Its dry climate, thin atmosphere and geographical location far away from urban light pollution make it one of the ideal astronomical observation points in the northern hemisphere. The observatory brings together some of the world's top telescopes and records the exploration of the universe for more than half a century.

Kitt Peak Observatory. Image credit: NOIRLab

In 1958, the National Science Foundation of the United States selected Kitt Peak to establish the first national observatory in the United States, which was operated by the Association of Universities for Research in Astronomy (AURA). In March 1960, a 0.9-meter telescope was completed on Kitt Peak, marking the official completion and opening of the Kitt Peak Observatory. In 1982, the National Optical Astronomy Observatory (NOAO) was established, and Kitt Peak Observatory became part of it. In 2019, NOAO merged with other institutions to form the National Optical-Infrared Astronomy Research Laboratory (NOIRLab), and Kitt Peak Observatory was therefore managed by NOIRLab.

Kitt Peak Observatory has more than 20 optical telescopes. These facilities have made important contributions to many fields such as galaxy evolution, star formation, and discovery of extrasolar planets. They have provided valuable data for human understanding of the origin and structure of the universe and greatly promoted the development of astronomy. Now, Xiaoxing will introduce some of the main facilities and projects of Kitt Peak Observatory.

The Mayall Telescope. Image credit: Outdoor Project

The 4-meter Mayall Telescope is the largest optical telescope at Kitt Peak Observatory. It was named in honor of the observatory's second director, American astronomer Nicholas Mayall. It was put into operation in 1973 and was the second largest optical telescope in the world at the time, second only to the 5-meter Hale Telescope at Palomar Mountain Observatory. In 1976, the Mayall Telescope discovered methane ice on Pluto by performing spectral analysis on the surface of Pluto. This discovery provided important clues for studying the surface composition and atmospheric conditions of Pluto. In 1988, American astronomer Robert Fesen and others used it to discover the remains of supernova SN 1885A (SN 1885A is the first extragalactic supernova discovered in human history, located in the M31 galaxy). In 2018, the Mayall Telescope was transformed into the core equipment of the Dark Energy Spectroscopic Instrument (DESI), which is currently drawing the largest 3D map of the universe.

The Mayall Telescope. Image credit: NOIRLab

The 3.5-meter WIYN telescope began operation in 1994. It is the second largest optical telescope at Kitt Peak Observatory and has made many contributions in the fields of exoplanets. For example, in 2024, through the observation data of the WIYN telescope, a group of astronomers discovered that the orbital eccentricity of the exoplanet TIC 241249530 b reached 0.94, which is the exoplanet with the largest eccentricity discovered by the transit method.

WIYN telescope. Image credit: NOIRLab

The 1.6-meter McMath–Pierce solar telescope was built in 1962 and is named in honor of American astronomers Robert McMath and Keith Pierce. It is used to study the structure and spectrum of sunspots and was the world's largest solar telescope until 2019. This meritorious solar telescope was retired in 2017 and is currently being transformed into an astronomical science center.

McMath-Pierce Solar Telescope. Image credit: NOIRLab

The Spacewatch project is led by the University of Arizona's Lunar and Planetary Laboratory. It uses multiple telescopes at Kitt Peak Observatory to conduct sky surveys, mainly to search for asteroids and conduct follow-up observations. The project has been running since 1980 and is the project that has discovered the most asteroids in the world. In 2003, a citizen science project called "Fast Moving Objects (FMO)" was officially launched based on the data of the Spacewatch project. The FMO project encourages astronomy enthusiasts around the world to participate in the search for near-Earth asteroids. Participants only need to download the images taken by the Spacewatch project, identify suspicious "short lines" (due to the relatively fast movement of near-Earth asteroids, they often appear as a short straight line in images with a slightly longer exposure time), and then submit them. Unfortunately, due to a lack of funds, the FMO project ended in 2006. Before that, more than a dozen Chinese astronomy enthusiasts achieved outstanding results in the FMO project.

Suspected targets from the Fast Moving Objects Project. Image credit: FMO Project

In addition to scientific research, Kitt Peak Observatory also attaches great importance to public education and popular science. In addition to the FMO projects mentioned above, Kitt Peak Observatory also regularly holds various activities such as open days, night sky observations, and popular science lectures. At night, visitors can use telescopes to observe various types of celestial bodies; during the day, they can observe sunspots and solar prominences. These activities give the public the opportunity to get close to the starry sky and stimulate their curiosity and desire to explore the universe.

Members of the public stargazing at the Kitt Peak Observatory Visitor Center. Image credit: NOIRLab

For more than half a century, Kitt Peak Observatory has always been at the forefront of cosmic exploration. From mapping dark energy to capturing the strange orbits of exoplanets, from tracking the trajectories of asteroids to decoding the mysteries of the sun, every telescope here is a love letter from mankind to the universe. Kitt Peak Observatory is not only a research base for scientists, but also a bridge connecting humans and the stars. As those astronomy enthusiasts who shine in the FMO project have proved, curiosity about the universe has nothing to do with age or occupation. With just a beam of light and a clear sky, everyone can become an interpreter of the starry sky. This observatory standing on the top of the mountain will continue to depict the legend of the universe: exploration never stops, and the journey of mankind will always be to the sea of ​​stars.

References

(1) Kitt Peak National Observatory, https://kpno.noirlab.edu/

(2) Dark Energy Spectroscopic Instrument, https://www.desi.lbl.gov/

(3) Xu Zhijian, The Path of Discovery for Amateur Astronomers, Astronomy Enthusiasts, No. 3, 2022, pp. 78-81

(4) WIYN 3.5-meter Telescope at Kitt Peak Discovers Extremely Strange Orbit of Rare Exoplanet, Kitt Peak National Observatory, https://kpno.noirlab.edu/news/noirlab2418/

(5) Kitt Peak National Observatory, wikipedia, https://en.m.wikipedia.org/wiki/Kitt_Peak_National_Observatory

(6) Nicholas U. Mayall Telescope, wikipedia, https://en.m.wikipedia.org/wiki/Nicholas_U._Mayall_Telescope

(7) WIYN Observatory, wikipedia, https://en.m.wikipedia.org/wiki/WIYN_Observatory

(8) McMath–Pierce solar telescope, wikipedia, https://en.m.wikipedia.org/wiki/McMath%E2%80%93Pierce_solar_telescope

(9) WIYN 3.5m Observatory, https://www.wiyn.org/

(10) FMO Discoveries and Recoveries, FMO Project, https://spacewatch.lpl.arizona.edu/fmo/discoveries

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