Techsciencenews Home 

Explore Inventors Biography Alphabetically


Home A B C D E F G H I J K L M N O P Q R S T U V W X Y Z


Art | Business Studies | Citizenship | Countries | Design and Technology | Everyday life | Geography | History | Information Technology | Language and Literature | Mathematics | Music | People | Portals | Religion | Science | African Inventors | Invention Timeline | Space (Astronomy) | Main Menu



The Sphinx Observatory at the Jungfraujoch in the Swiss Alps; high altitude observatories are less affected by the atmosphere.

An observatory is a location used for observing terrestrial and/or celestial events. Astronomy, climatology/meteorology, geology, oceanography and volcanology are examples of disciplines for which observatories have been constructed. Historically, observatories were as simple as containing an astronomical sextant (for measuring the distance between stars) or Stonehenge (which has some alignments on astronomical phenomena).


Astronomical observatories

Ground-based observatories

Paranal Observatory, home of the Very Large Telescope, a cluster of four large (8.2 meter diameter) telescopes.

Ground-based observatories, located on the surface of Earth, are used to make observations in the radio and visible light portions of the electromagnetic spectrum. Most optical telescopes 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".[1] Sites that meet the above criteria for modern observatories include the southwestern United States, Hawaii, the Andes Mountains region, Australia and the mountainous Sierra Negra in Mexico.[2] Major optical observatories include Mauna Kea, HI, USA, Roque de los Muchachos Observatory in Spain, Paranal Observatory in Chile and Kitt Peak observatory in the USA.

The largest observatory in the world is the Large Millimeter Telescope located in the high mountains of the state of Puebla in Mexico.

Radio observatories

Beginning in 1930s, radio telescopes have been built for use in the field of radio astronomy to see space very close up. Such an instrument, or a collection of them, with outbuildings for such things as control centres, data reduction centers, and maintenance are called radio observatories. Radio observatories are similarly located far from major centers of population to avoid electromagnetic interference (EMI) from radio, TV, radar, and other EMI emitting devices. But unlike optical observatories, radio observatories will be placed in valleys to further shield them from EMI. Some of the major radio observatories are at Socorro, in New Mexico, USA, Jodrell Bank in the UK, Arecibo, Puerto Rico, Parkes at New South Wales, Australia and Chajnantor in Chile.

Oldest astronomical observatories

"El Caracol" observatory temple at Chichen Itza, Mexico.

The oldest proto-observatories, in the sense of a private observation post,[3] include:

  • Chankillo, Peru
  • El Caracol, Mexico
  • Abu Simbel, Egypt
  • Stonehenge, Great Britain
  • Kokino, Republic of Macedonia
  • Goseck circle, Germany
  • Ujjain, India
  • Arkaim, Russia
  • Cheomseongdae, South Korea
  • Angkor Wat, Cambodia
Current status of Maragheh observatory at Maragheh, Iran.

The oldest true observatories, in the sense of a specialized research institute,[4][5][6] include:

Space-based observatories

The Hubble Space Telescope, a space-based observatory

Space-based observatories are telescopes or other instruments that are located in outer space, many in orbit around the Earth. Space-based observatories 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 radiation, X-rays, and gamma rays and is partially opaque to infrared radiation so observations in these portions of the electromagnetic spectrum are best carried out from a location above the atmosphere of our planet.[7] 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.[8] As a result, the angular resolution of space telescopes such as the Hubble Space Telescope 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 can be serviced by the Space Shuttle while many other space telescopes cannot be serviced at all.

Volcano observatories

A Volcano observatory is an institution that conducts research and monitoring of a volcano. Mobile volcano observatories exist with the USGS VDAP (Volcano Disaster Assistance Program), to be deployed on demand.

Observatories in Islamic History

Astronomy practiced in ancient civilizations was associated with astrology and fortune telling. This association cast shades of doubt on the practice in the minds of early Muslims. However, with the establishment of the Islamic civilization, which rejected astrology and fortune telling as contradictory to Islamic beliefs, astronomy was separated and recognized as a discipline based on scientific principles. This separation was not accidental: it was based on scientific experiments, analogy and deduction, which Muslims applied in order to meet their need for determining the qiblah (direction of Mecca) and prayer times. All major mosques accordingly appointed astronomers, who used instruments invented by Muslims.

The Marageh Observatory

This observatory, considered one of the most important observatories in Islamic history, was built in the seventh century AH (after Hijrah), making this century accordingly the most important era in the history of Islamic observatories. This observatory, the ruins of which can still be seen today, was built outside the city of Marageh, close to the city of Tabriz in Iran. The observatory was built by Holako's brother, Manjo, who was interested in mathematics and astronomy. He entrusted Jamal Ad-Din Bin Muhammad Bin Az-Zazidi Al-Bukhari with the establishment of this observatory and sought the assistance of a large number of scientists, such as Nasr Ad-Din At-Tusi, Ali Bin Umar Al-Ghazwini, Muayid Ad-Din Al-‘Ardi, Fakhr Ad-Din Al-Maraghi, and Muhiyd-Din Al-Maghribi.

The Samarkand Observatory

This observatory was established in Sarmarkand by Ulugh Beg, the grandson of Tamerlane (Timur the Lame). The location of this observatory was discovered in 1908, when Russian archaeologist Viatken discovered an endowment document that stated the observatory's exact location. While working at the excavation site, he found one of the most important astronomical instruments used at the observatory: a large arch that had been used to determine midday.[9]


  • Equatorial room
  • Fundamental station
  • List of astronomical observatories
  • List of observatory codes
  • Space observatory
  • Timeline of telescopes, observatories, and observing technology


  1. ^ Chaisson, Eric; McMillan, Steve (2002). Astronomy Today, Fourth Edition. Prentice Hall. pp. 116–119. 
  2. ^ Chaisson, Eric; McMillan, Steve (2002). Astronomy Today, Fourth Edition. Prentice Hall. pp. 119. 
  3. ^ Micheau, Francoise, "The Scientific Institutions in the Medieval Near East", pp. 992–3 , in (Rashed & Morelon 1996, pp. 985-1007)
  4. ^ Peter Barrett (2004), Science and Theology Since Copernicus: The Search for Understanding, p. 18, Continuum International Publishing Group, ISBN 056708969X
  5. ^ Micheau, Francoise, "The Scientific Institutions in the Medieval Near East", pp. 992–3 , in Rashed, Roshdi; Morelon, Régis (1996), Encyclopedia of the History of Arabic Science, Routledge, pp. 985–1007, ISBN 0415124107 
  6. ^ Kennedy, Edward S. (1962), "Review: The Observatory in Islam and Its Place in the General History of the Observatory by Aydin Sayili", Isis 53 (2): 237–239, doi:10.1086/349558 
  7. ^ Chaisson, Eric; McMillan, Steve (2002). Astronomy Today, Fourth Edition. Prentice Hall. 
  8. ^ "A Brief History of the Hubble Space Telescope: Why a Space Telescope?". NASA. Retrieved 2006-08-14. 
  9. ^ Observatories in Islamic History

External links

Useful Links