Editing European Southern Observatory (section)

== History ==

{{multiple image
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 |image1 = ESO Headquarters.jpg
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 |caption1 = The ESO headquarters in [[Garching]], Germany, in 1997
 |caption2 = The same site in 2014, a year after a new extension was built (in the foreground)
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The idea that European astronomers should establish a common large observatory was broached by [[Walter Baade]] and [[Jan Oort]] at the [[Leiden Observatory]] in the Netherlands in spring 1953.<ref>{{cite book |title=ESO's Early History |author=Adriaan Blaauw |publisher=ESO |date=1991 |page=4}}</ref> It was pursued by Oort, who gathered a group of astronomers in Leiden to consider it on 21 June that year. Immediately thereafter, the subject was further discussed at the Groningen conference in the Netherlands. On 26 January 1954, an ESO declaration was signed by astronomers from six European countries expressing the wish that a joint European observatory be established in the southern hemisphere.<ref name="ESO Timeline">{{cite web |url=http://www.eso.org/public/about-eso/timeline.html |title=ESO Timeline |access-date=2011-04-28 |archive-date=2013-09-27 |archive-url=https://web.archive.org/web/20130927205026/http://www.eso.org/public/about-eso/timeline.html |url-status=live }}</ref>

At the time, all [[reflector telescope]]s with an [[aperture]] of 2 metres or more were located in the northern hemisphere. The decision to build the observatory in the southern hemisphere resulted from the necessity of observing the southern sky; some research subjects (such as the central parts of the [[Milky Way]] and the [[Magellanic Clouds]]) were accessible only from the southern hemisphere.<ref>{{cite book |title=Europe's Quest for the Universe |author=Lodewijk Woltjer |publisher=EDP Sciences |date=2006}}</ref>

{| class="wikitable floatright" style="font-size: 0.95em; width: 220px;"
! Director General !! In office
|-
| [[Otto Heckmann]]
| align=center | 1962–1969
|-
| [[Adriaan Blaauw]]
| align=center | 1970–1974
|-
| [[Lodewijk Woltjer]]
| align=center | 1975–1987
|-
| Harry van der Laan
| align=center | 1988–1992
|-
| [[Riccardo Giacconi]]
| align=center | 1993–1999
|-
| [[Catherine Cesarsky]]
| align=center | 1999–2007
|-
| [[Tim de Zeeuw]]
| align=center | 2007–2017
|-
| [[Xavier Barcons]]
| align=center | 2017–present
|-
| colspan=2 style="background-color: #f2f2f2; font-size: 0.90em; padding: 6px 0 4px 4px;" | Source: ''www.eso.org, about ESO''<ref>{{cite web |url=http://www.eso.org/public/about-eso/dg-office/previous-dg.html |title=Past ESO Directors General |access-date=2011-04-29 |archive-date=2011-05-13 |archive-url=https://web.archive.org/web/20110513235223/http://www.eso.org/public/about-eso/dg-office/previous-dg.html |url-status=live }}</ref>
|}

It was initially planned to set up telescopes in South Africa where several European observatories were located ([[Boyden Observatory]]), but tests from 1955 to 1962 demonstrated that a site in the [[Andes]] was preferable: When [[Jürgen Stock (astronomer)|Jürgen Stock]] enthusiastically reported his observations from [[Chile]], [[Otto Heckmann]] decided to leave the South African project on hold. ESO—at that time about to sign the contracts with South Africa—decided to establish their observatory in Chile.<ref>{{Cite web |last=DIRK H. LORENZEN |title=Obituary JÜRGE STOCK 1923 – 2004 |url=https://www.eso.org/sci/publications/messenger/archive/no.117-sep04/messenger-no117-65-65.pdf |website=ESO |access-date=2024-05-08 |archive-date=2024-05-08 |archive-url=https://web.archive.org/web/20240508204158/https://www.eso.org/sci/publications/messenger/archive/no.117-sep04/messenger-no117-65-65.pdf |url-status=live }}</ref>  The ESO Convention was signed 5 October 1962 by Belgium, Germany, France, the Netherlands and Sweden. Otto Heckmann was nominated as the organisation's first director general on 1 November 1962. On 15 November 1963 Chile was chosen as the site for ESO's observatory.<ref>{{cite book |title=ESO's Early History |author=Adriaan Blaauw |publisher=ESO |date=1991}}</ref>

[[File:Directors General of ESO – First Stone Ceremony.jpg|thumb|upright=1.1|Directors general of ESO (from left to right): Lodewijk Woltjer, Harry van der Laan, Catherine Cesarsky, Tim de Zeeuw and Xavier Barcons]]
A preliminary proposal for a convention of astronomy organisations in these five countries was drafted in 1954. Although some amendments were made in the initial document, the convention proceeded slowly until 1960 when it was discussed during that year's committee meeting. The new draft was examined in detail, and a council member of [[CERN]] (the European Organization for Nuclear Research) highlighted the need for a convention between governments (in addition to organisations).<ref>{{cite book |title=ESO's Early History |author=Adriaan Blaauw |publisher=ESO |date=1991 |page=7}}</ref>
The convention and government involvement became pressing due to rapidly rising costs of site-testing expeditions. The final 1962 version was largely adopted from the CERN convention, due to similarities between the organisations and the dual membership of some members.<ref>{{cite book |title=ESO's Early History |author=Adriaan Blaauw |publisher=ESO |date=1991 |page=8}}</ref>

In 1966, the first ESO telescope at the La Silla site in Chile began operating.<ref name="ESO Timeline"/> Because CERN (like ESO) had sophisticated instrumentation, the astronomy organisation frequently turned to the nuclear-research body for advice and a collaborative agreement between ESO and CERN was signed in 1970. Several months later, ESO's telescope division moved into a CERN building in [[Geneva]] and ESO's Sky Atlas Laboratory was established on CERN property.<ref>{{cite book |title=ESO's Early History |author=Adriaan Blaauw |publisher=ESO |date=1991 |pages=169, 179}}</ref> ESO's European departments moved into the new ESO headquarters in [[Garching]] (near [[Munich]]), Germany, in 1980.

In 2015, [[Guillem Anglada-Escudé]] confirmed the existence of [[Proxima Centauri b]] at the Southern Observatory.

=== Member states ===
{| class="wikitable sortable floatleft" style="margin-top: 8px;"
! Country
! Accession<ref>{{cite web| url=http://www.eso.org/public/about-eso/memberstates/| title=Member States| last=| website=www.eso.org| access-date=2015-05-11| archive-date=2020-06-15| archive-url=https://web.archive.org/web/20200615083311/https://www.eso.org/public/about-eso/memberstates/| url-status=live}}</ref>
|-
| {{BEL}}
| {{sort|1962|1962}}
|-
| {{DEU}}
| {{sort|1962|1962}}
|-
| {{FRA}}
| {{sort|1962|1962}}
|-
| {{NED}}
| {{sort|1964|1964}}
|-
| {{SWE}}
| {{sort|1964|1964}}
|-
| {{DEN}}
| {{sort|1967|1967}}
|-
| {{SUI}}
| {{sort|1982|1982}}
|-
| {{ITA}}
| {{sort|1982|1982}}
|-
| {{POR}}
| {{sort|2001-1-1|1 January 2001}}
|-
| {{UK}}
| {{sort|2002-7-8|8 July 2002}}
|-
| {{FIN}}
| {{sort|2004-7-1|1 July 2004}}
|-
| {{ESP}}
| {{sort|2006-7-1|1 July 2006}}
|-
| {{CZE}}
| {{sort|2007-1-1|1 January 2007}}
|-
| {{AUT}}
| {{sort|2008-7-1|1 July 2008}}
|-
| {{POL}}
| {{sort|2014-10-28|28 October 2014}}
|-
| {{IRL}}
| {{sort|2018-9-28|28 September 2018}}
|-
|}

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