An observatory is a location used for observing terrestrial, marine, or celestial events.

Astronomy 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 includ ...

climatology Climatology (from Greek , ''klima'', "slope"; and , '' -logia'') or climate science is the scientific study of Earth's climate, typically defined as weather conditions averaged over a period of at least 30 years. Climate concerns the atmospher ...

meteorology Meteorology is the scientific study of the Earth's atmosphere and short-term atmospheric phenomena (i.e. weather), with a focus on weather forecasting. It has applications in the military, aviation, energy production, transport, agricultur ...

geophysics Geophysics () is a subject of natural science concerned with the physical processes and Physical property, properties of Earth and its surrounding space environment, and the use of quantitative methods for their analysis. Geophysicists conduct i ...

oceanography Oceanography (), also known as oceanology, sea science, ocean science, and marine science, is the scientific study of the ocean, including its physics, chemistry, biology, and geology. It is an Earth science, which covers a wide range of to ...

and

volcanology Volcanology (also spelled vulcanology) is the study of volcanoes, lava, magma and related geology, geological, geophysical and geochemistry, geochemical phenomena (volcanism). The term ''volcanology'' is derived from the Latin language, Latin ...

are examples of disciplines for which observatories have been constructed. The term ''observatoire'' has been used in French since at least 1976 to denote any institution that compiles and presents data on a particular subject (such as public health observatory) or for a particular geographic area ( European Audiovisual Observatory).

Astronomical observatories

Astronomical observatories are mainly divided into four categories: space-based, airborne, ground-based, and underground-based. Historically, ground-based observatories were as simple as containing a mural instrument (for measuring the angle between

star A star is a luminous spheroid of plasma (physics), plasma held together by Self-gravitation, self-gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night sk ...

s) or

Stonehenge Stonehenge is a prehistoric Megalith, megalithic structure on Salisbury Plain in Wiltshire, England, west of Amesbury. It consists of an outer ring of vertical sarsen standing stones, each around high, wide, and weighing around 25 tons, to ...

(which has some alignments on astronomical phenomena).

Ground-based observatories

Ground-based observatories, located on the surface of Earth, are used to make observations in the

radio Radio is the technology of communicating using radio waves. Radio waves are electromagnetic waves of frequency between 3 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connec ...

and visible light portions of the

electromagnetic spectrum The electromagnetic spectrum is the full range of electromagnetic radiation, organized by frequency or wavelength. The spectrum is divided into separate bands, with different names for the electromagnetic waves within each band. From low to high ...

. Most

optical telescope An optical telescope gathers and focus (optics), focuses light mainly from the visible spectrum, visible part of the electromagnetic spectrum, to create a magnification, magnified image for direct visual inspection, to make a photograph, or to co ...

s are housed within a dome or similar structure, to protect the delicate instruments from the elements. Telescope domes have a slit or other opening in the roof that can be opened during observing, and closed when the telescope is not in use. In most cases, the entire upper portion of the telescope dome can be rotated to allow the instrument to observe different sections of the night sky. Radio telescopes usually do not have domes. For optical telescopes, most ground-based observatories are located far from major centers of population, to avoid the effects of light pollution. The ideal locations for modern observatories are sites that have dark skies, a large percentage of clear nights per year, dry air, and are at high elevations. At high elevations, the Earth's atmosphere is thinner, thereby minimizing the effects of atmospheric turbulence and resulting in better astronomical " seeing". Sites that meet the above criteria for modern observatories include the southwestern United States,

Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...

Canary Islands The Canary Islands (; ) or Canaries are an archipelago in the Atlantic Ocean and the southernmost Autonomous communities of Spain, Autonomous Community of Spain. They are located in the northwest of Africa, with the closest point to the cont ...

, the

Andes The Andes ( ), Andes Mountains or Andean Mountain Range (; ) are the List of longest mountain chains on Earth, longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range ...

, and high mountains in

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

such as Sierra Negra. Major optical observatories include Mauna Kea Observatory and Kitt Peak National Observatory in the US,

Roque de los Muchachos Observatory Roque de los Muchachos Observatory (, ORM) is an astronomical observatory located in the municipality of Garafía on the island of La Palma in the Canary Islands, Spain. The observatory site is operated by the Instituto de Astrofísica de Can ...

in Spain, and Paranal Observatory and Cerro Tololo Inter-American Observatory in

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 ...

. Specific research study performed in 2009 shows that the best possible location for ground-based observatory on Earth is Ridge A—a place in the central part of Eastern Antarctica. This location provides the least atmospheric disturbances and best visibility.

Solar observatories

Radio observatories

Beginning in 1933,

radio telescope 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 ...

s have been built for use in the field of

radio astronomy Radio astronomy is a subfield of astronomy that studies Astronomical object, celestial objects using radio waves. It started in 1933, when Karl Jansky at Bell Telephone Laboratories reported radiation coming from the Milky Way. Subsequent observat ...

to observe the Universe in the radio portion of the electromagnetic spectrum. Such an instrument, or collection of instruments, with supporting facilities such as control centres, visitor housing, data reduction centers, and/or maintenance facilities are called ''radio observatories''. Radio observatories are similarly located far from major population centers to avoid electromagnetic interference (EMI) from

, TV,

radar Radar is a system that uses radio waves to determine the distance ('' ranging''), direction ( azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method used to detect and track ...

, and other EMI emitting devices, but unlike optical observatories, radio observatories can be placed in

valley A valley is an elongated low area often running between hills or mountains and typically containing a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams over ...

s for further EMI shielding. Some of the world's major radio observatories include the

Very Large Array The Karl G. Jansky Very Large Array (VLA) is a centimeter-wavelength radio astronomy observatory in the southwestern United States built in the 1970s. It lies in central New Mexico on the Plains of San Agustin, between the towns of Magdalena, Ne ...

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 ...

, United States,

Jodrell Bank Jodrell Bank Observatory ( ) in Cheshire, England hosts a number of radio telescopes as part of the Jodrell Bank Centre for Astrophysics at the University of Manchester. The observatory was established in 1945 by Bernard Lovell, a radio astron ...

in the UK, Arecibo in

Puerto Rico ; abbreviated PR), officially the Commonwealth of Puerto Rico, is a Government of Puerto Rico, self-governing Caribbean Geography of Puerto Rico, archipelago and island organized as an Territories of the United States, unincorporated territo ...

, Parkes in

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

, Australia, and Chajnantor in

. A related discipline is Very-long-baseline interferometry (VLBI).

Highest astronomical observatories

Since the mid-20th century, a number of astronomical observatories have been constructed at very high altitudes, above . The largest and most notable of these is the Mauna Kea Observatory, located near the summit of a volcano in Hawaiʻi. The Chacaltaya Astrophysical Observatory in Bolivia, at , was the world's highest permanent astronomical observatory from the time of its construction during the 1940s until 2009. It has now been surpassed by the new University of Tokyo Atacama Observatory, an optical-infrared telescope on a remote mountaintop in the Atacama Desert of Chile.

Oldest astronomical observatories

The oldest proto-observatories, in the sense of an observation post for astronomy, * Wurdi Youang, Australia * Zorats Karer, Karahunj, Armenia * Loughcrew, Ireland * Newgrange, Ireland *

, Great Britain * Chankillo, Peru * El Caracol, Mexico * Buto, Egypt *

Abu Simbel Abu Simbel is a historic site comprising two massive Rock-cut architecture, rock-cut Egyptian temple, temples in the village of Abu Simbel (village), Abu Simbel (), Aswan Governorate, Upper Egypt, near the border with Sudan. It is located on t ...

, Egypt * Kokino, Kumanovo, North Macedonia * Observatory at Rhodes, Greece * Goseck circle, Germany * Ujjain, India * Arkaim, Russia * Cheomseongdae, South Korea *

Angkor Wat Angkor Wat (; , "City/Capital of Wat, Temples") is a Buddhism and Hinduism, Hindu-Buddhist temple complex in Cambodia. Located on a site measuring within the ancient Khmer Empire, Khmer capital city of Angkor, it was originally constructed ...

, Cambodia The oldest true observatories, in the sense of a specialized

research institute A research institute, research centre, or research organization is an establishment founded for doing research. Research institutes may specialize in basic research or may be oriented to applied research. Although the term often implies natural ...

,Peter Barrett (2004), ''Science and Theology Since Copernicus: The Search for Understanding'', p. 18, Continuum International Publishing Group, . include: * 825: Al-Shammisiyyah Observatory,

Baghdad Baghdad ( or ; , ) is the capital and List of largest cities of Iraq, largest city of Iraq, located along the Tigris in the central part of the country. With a population exceeding 7 million, it ranks among the List of largest cities in the A ...

, Iraq * 869: Mahodayapuram Observatory,

Kerala Kerala ( , ) is a States and union territories of India, state on the Malabar Coast of India. It was formed on 1 November 1956, following the passage of the States Reorganisation Act, by combining Malayalam-speaking regions of the erstwhile ...

, India * 1259: Maragheh Observatory,

Azerbaijan Azerbaijan, officially the Republic of Azerbaijan, is a Boundaries between the continents, transcontinental and landlocked country at the boundary of West Asia and Eastern Europe. It is a part of the South Caucasus region and is bounded by ...

, Iran * 1276: Gaocheng Astronomical Observatory, China * 1420: Ulugh Beg Observatory, Samarqand, Uzbekistan * 1442: Beijing Ancient Observatory, China * 1577: Constantinople Observatory of Taqi ad-Din, Turkey * 1580: Uraniborg, Denmark * 1581: Stjerneborg, Denmark * 1633: Leiden Observatory, Netherlands * 1642: Panzano Observatory, Italy * 1642: Round Tower, Denmark * 1667: Paris Observatory, France * 1675: Royal Greenwich Observatory, England * 1695: Sukharev Tower, Russia * 1711: Berlin Observatory, Germany * 1724: Jantar Mantar, India * 1753: Stockholm Observatory, Sweden * 1753: Vilnius University Observatory, Lithuania * 1753: Real Instituto y Observatorio de la Armada, Spain * 1759: Trieste Observatory, Italy. * 1757: Macfarlane Observatory, Scotland. * 1759: Turin Observatory, Italy. * 1764: Brera Astronomical Observatory, Italy. * 1765: Mohr Observatory, Indonesia. * 1771: Lviv Observatory, Ukraine. * 1774: Observatory of the Vatican, Italy. * 1785: Dunsink Observatory, Ireland. * 1786: Madras Observatory, India. * 1789: Armagh Observatory, Northern Ireland. * 1790: Royal Observatory of Madrid, Spain, * 1803: National Astronomical Observatory, Bogotá, Colombia. * 1811: Tartu Old Observatory,

Estonia Estonia, officially the Republic of Estonia, is a country in Northern Europe. It is bordered to the north by the Gulf of Finland across from Finland, to the west by the Baltic Sea across from Sweden, to the south by Latvia, and to the east by Ru ...

* 1812: Astronomical Observatory of Capodimonte, Naples, Italy * 1830/1842: Depot of Charts & Instruments/US Naval Observatory, US * 1830: Yale University Observatory Atheneum, US * 1834: Helsinki University Observatory, Finland * 1838: Hopkins Observatory, Williams College, US * 1838: Loomis Observatory, Western Reserve Academy, US * 1839: Pulkovo Observatory, Russia * 1842: Cincinnati Observatory, US * 1844: Georgetown University Astronomical Observatory, US * 1847:

Harvard College Observatory The Harvard College Observatory (HCO) is an institution managing a complex of buildings and multiple instruments used for astronomical research by the Harvard University Department of Astronomy. It is located in Cambridge, Massachusetts, United St ...

, US * 1854: Detroit Observatory, US * 1871: Argentine National Observatory, Argentina * 1873: Quito Astronomical Observatory, Ecuador * 1878: Lisbon Astronomical Observatory, Portugal * 1884: McCormick Observatory, US * 1888: Lick Observatory, US * 1890: Smithsonian Astrophysical Observatory, US * 1894: Lowell Observatory, US * 1895: Theodor Jacobsen Observatory, US * 1897: Yerkes Observatory, US * 1899: Kodaikanal Solar Observatory, India

Space-based observatories

Space-based observatories are telescopes or other instruments that are located in outer space, many in

orbit In celestial mechanics, an orbit (also known as orbital revolution) is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an ...

around the Earth. Space telescopes can be used to observe astronomical objects at wavelengths of the electromagnetic spectrum that cannot penetrate the Earth's atmosphere and are thus impossible to observe using ground-based telescopes. The Earth's atmosphere is opaque to

ultraviolet Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of ...

radiation,

X-rays An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...

, and gamma rays and is partially opaque to

infrared Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those ...

radiation so observations in these portions of the electromagnetic spectrum are best carried out from a location above the atmosphere of our planet. Another advantage of space-based telescopes is that, because of their location above the Earth's atmosphere, their images are free from the effects of atmospheric turbulence that plague ground-based observations. As a result, the angular resolution of space telescopes such as the

Hubble Space Telescope The Hubble Space Telescope (HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the Orbiting Solar Observatory, first space telescope, but it is one of the largest and most ...

is often much smaller than a ground-based telescope with a similar aperture. However, all these advantages do come with a price. Space telescopes are much more expensive to build than ground-based telescopes. Due to their location, space telescopes are also extremely difficult to maintain. The Hubble Space Telescope was able to be serviced by the

Space Shuttle The Space Shuttle is a retired, partially reusable launch system, reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration (NASA) as part of the Space Shuttle program. ...

s while many other space telescopes cannot be serviced.

Airborne observatories

Airborne observatories have the advantage of height over ground installations, putting them above most of the Earth's atmosphere. They also have an advantage over space telescopes: The instruments can be deployed, repaired and updated much more quickly and inexpensively. The Kuiper Airborne Observatory and the Stratospheric Observatory for Infrared Astronomy use airplanes to observe in the

, which is absorbed by

water vapor Water vapor, water vapour, or aqueous vapor is the gaseous phase of Properties of water, water. It is one Phase (matter), state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from th ...

in the atmosphere. High-altitude balloons for X-ray astronomy have been used in a variety of countries.

Neutrino observatories

Example underground, underwater or under ice neutrino observatories include: * 1998–2003 Gallium Neutrino Observatory * 1999–2006 Sudbury Neutrino Observatory * 2003 Baikal Deep Underwater Neutrino Telescope * 2010 IceCube Neutrino Observatory * 2012 Helium and Lead Observatory (HALO)

Meteorological observatories

Example meteorological observatories include: * 1762 Kremsmünster Observatory, Austria * 1781 Hohenpeißenberg Meteorological Observatory, Germany * 1841 Colaba Observatory, India * 1868 Kandilli Observatory, Türkiye * 1869 New York Meteorological Observatory in

Central Park Central Park is an urban park between the Upper West Side and Upper East Side neighborhoods of Manhattan in New York City, and the first landscaped park in the United States. It is the List of parks in New York City, sixth-largest park in the ...

, New York * 1871 Argentine National Observatory, Argentina * 1883 Hong Kong Observatory, Hong Kong * 1885 Blue Hill Meteorological Observatory, Massachusetts * 1932 Mount Washington Observatory, New Hampshire * 1956 Mauna Loa Observatory, Hawaii

Marine observatories

A marine observatory is a scientific institution whose main task is to make observations in the fields of meteorology, geomagnetism and tides that are important for the navy and civil shipping. An astronomical observatory is usually also attached. Some of these observatories also deal with nautical weather forecasts and storm warnings, astronomical time services, nautical calendars and seismology. Example marine observatories include: * 1676 Royal Greenwich Observatory at London * 1753 Real Instituto y Observatorio de la Armada in San Fernando, Spain * 1830 United States Naval Observatory * 1868 German Maritime Observatory in Hamburg * 1871–1918 Austro-Hungarian Pola Naval Observatory, in what is now Pula, Croatia * 1882 Observatoire Oceanologique de Villefranche, France * 1908 St. Andrews Biological Station, Canada * 2006 European Multidisciplinary Seafloor and water column Observatory (EMSO)

Magnetic observatories

A magnetic observatory is a facility which precisely measures the total intensity of Earth's

magnetic field A magnetic field (sometimes called B-field) is a physical field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular ...

for field strength and direction at standard intervals. Geomagnetic observatories are most useful when located away from human activities to avoid disturbances of anthropogenic origin, and the observation data is collected at a fixed location continuously for decades. Magnetic observations are aggregated, processed, quality checked and made public through data centers such as INTERMAGNET. The types of measuring equipment at an observatory may include magnetometers (torsion, declination-inclination fluxgate, proton precession, Overhauser-effect), variometer (3-component vector, total-field scalar), dip circle,

inclinometer An inclinometer or clinometer is an measuring instrument, instrument used for measuring angles of slope, elevation, or depression (geology), depression of an object with respect to gravity's direction. It is also known as a ''tilt indicator'', ' ...

, earth inductor,

theodolite A theodolite () is a precision optical instrument for measuring angles between designated visible points in the horizontal and vertical planes. The traditional use has been for land surveying, but it is also used extensively for building and ...

, self-recording magnetograph, magnetic declinometer, azimuth compass. Once a week at the absolute reference point calibration measurements are performed. Example magnetic observatories include: * 1833 Göttingen Observatory, Germany * 1840 Toronto Magnetic and Meteorological Observatory, Canada * 1842

Kew Observatory The King's Observatory (called for many years the Kew Observatory) is a Grade I listed building in Richmond, London. Now a private dwelling, it formerly housed an astronomical observatory, astronomical and Terrestrial magnetism, terrestrial mag ...

, UK * 1904 Eskdalemuir Observatory, UK * 1961 Boulder Geomagnetic Observatory, Colorado

Seismic observatories

Example seismic observation projects and observatories include: * International Seismological Summary * Lamont–Doherty Earth Observatory * EarthScope * GEOSCOPE Observatory * World-Wide Standardized Seismograph Network

Geodetic observatories

Cosmic-ray observatories

Gravitational wave observatories

Example gravitational wave observatories include: * LIGO * European Gravitational Observatory

Wildlife observatories

Volcano observatories

A volcano observatory is an institution that conducts the monitoring of a

volcano A volcano is commonly defined as a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most oft ...

as well as research in order to understand the potential impacts of active volcanism. Among the best known are the Hawaiian Volcano Observatory and the Vesuvius Observatory. Mobile volcano observatories exist with the

USGS The United States Geological Survey (USGS), founded as the Geological Survey, is an government agency, agency of the United States Department of the Interior, U.S. Department of the Interior whose work spans the disciplines of biology, geograp ...

VDAP (Volcano Disaster Assistance Program), to be deployed on demand. Each volcano observatory has a geographic area of responsibility it is assigned to whereby the observatory is tasked with spreading activity forecasts, analyzing potential volcanic activity threats and cooperating with communities in preparation for volcanic eruption.

References

External links

Dearborn Observatory Records, Northwestern University Archives, Evanston, Illinois
(archived 4 September 2015)

* ttp://www.observatory-guide.org/ Milkyweb Astronomical Observatory Guideworld's largest database of astronomical observatories since 2000about 2000 entries
List of amateur and professional observatories in North America with custom weather forecasts

* ttp://physics.usc.edu/solar/ Mt. Wilson Observatory
Observatories with Clear Sky Clocks
{{Authority control Scientific organizations Scientific observation Scientific buildings

Astronomical observatories

Ground-based observatories

Solar observatories

Radio observatories

Highest astronomical observatories

Oldest astronomical observatories

Space-based observatories

Airborne observatories

Neutrino observatories

Meteorological observatories

See also

Marine observatories

See also

Magnetic observatories

Seismic observatories

Geodetic observatories

Cosmic-ray observatories

Gravitational wave observatories

Wildlife observatories

Volcano observatories

See also

References

Further reading

External links