An observatory is a location utilised for the purpose of observing terrestrial and/or celestial events. Astronomy, astrology, climatology, geology, meteorology and volcanology are examples of disciplines for which observatories have been constructed. Historically, observatories were as simple as containing a sextant (for measuring the distance between stars) or Stonehenge (which has some alignments on astronomical phenomena). Modern astronomical observatories typically contain one or more permanently mounted telescopes contained in buildings with a rotating or removeable dome. Beginning in the 1940's, radio telescopes were built and began to detect significant radio sources in the universe. 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 . Some of the major ones are at Jodrell Bank in England, Arecibo, Puerto Rico, Parkes in N.S.W., Australia, Socorro, in NM, U.S.A., and Mauna Kea, HI, USA. Within the last twenty years, many space-based observatories have been launched, introducing a new use of the term.

See also

• Volcano observatory
• Space observatory
• Timeline of telescopes, observatories, and observing technology
• list of observatories