Editing European Southern Observatory (section)

==== Very Large Telescope ====
{{Main|Very Large Telescope}}
{{multiple image
 |direction = vertical
 |align     = right
 |width     = 225
 |image1    = Paranal platform.jpg
 |image2    = The VLT´s Laser Guide Star.jpg
 |caption1  = [[Very Large Telescope]] (VLT). Complex of four large telescopes and several smaller ones.
 |caption2  = VLT Laser Guide Star. The orange laser beam from the telescope is used for [[adaptive optics]].
}}

The main facility at Paranal is the VLT, which consists of four nearly identical {{convert|8.2|m|adj=on}} unit telescopes (UTs), each hosting two or three instruments. These large telescopes can also work together in groups of two or three as a giant [[Interferometry|interferometer]]. The ESO Very Large Telescope Interferometer (VLTI) allows astronomers to see details up to 25 times finer than those seen with the individual telescopes. The light beams are combined in the VLTI with a complex system of mirrors in tunnels, where the light paths must diverge less than 1/1000&nbsp;mm over 100 metres. The VLTI can achieve an [[angular resolution]] of milliarcseconds, equivalent to the ability to see the headlights of a car on the Moon.<ref>{{cite web |url=http://www.eso.org/public/teles-instr/vlt.html |title=The Very Large Telescope |access-date=2011-05-04 |archive-date=2013-08-27 |archive-url=https://web.archive.org/web/20130827183731/http://www.eso.org/public/teles-instr/vlt.html |url-status=live }}</ref>

The first of the UTs had its [[First light (astronomy)|first light]] in May 1998, and was offered to the astronomical community on 1 April 1999.<ref name="A Great Moment for Astronomy">{{cite news |date=27 May 1998 |title=A Great Moment for Astronomy |url=http://www.eso.org/public/news/eso9820/ |publisher=ESO |access-date=2011-05-04 |archive-date=2020-05-21 |archive-url=https://web.archive.org/web/20200521203429/https://www.eso.org/public/news/eso9820/ |url-status=live }}</ref> The other telescopes followed suit in 1999 and 2000, making the VLT fully operational. Four 1.8-metre auxiliary telescopes (ATs), installed between 2004 and 2007, have been added to the VLTI for accessibility when the UTs are used for other projects.<ref>{{cite news |date=22 December 2006 |title=Little Brother Joins the Large Family |url=http://www.eso.org/public/news/eso0651/ |publisher=ESO |access-date=2011-05-04 |archive-date=2020-05-20 |archive-url=https://web.archive.org/web/20200520092402/https://www.eso.org/public/news/eso0651/ |url-status=live }}</ref>

Data from the VLT have led to the publication of an average of more than one peer-reviewed scientific paper per day; in 2017, over 600 reviewed scientific papers were published based on VLT data.<ref name="ESOstats"/> The VLT's scientific discoveries include imaging an extrasolar planet,<ref>{{cite news |date=21 November 2008 |title=Beta Pictoris planet finally imaged? |url=http://www.eso.org/public/news/eso0842/ |publisher=ESO |access-date=2011-05-04 |archive-date=2020-05-20 |archive-url=https://web.archive.org/web/20200520114538/https://www.eso.org/public/news/eso0842/ |url-status=live }}</ref> tracking individual stars moving around the [[supermassive black hole]] at the centre of the Milky Way<ref name="eso.org">{{cite news |date=10 December 2008 |title=Unprecedented 16-Year Long Study Tracks Stars Orbiting Milky Way Black Hole |url=http://www.eso.org/public/news/eso0846/ |publisher=ESO |access-date=2011-05-04 |archive-date=2020-05-20 |archive-url=https://web.archive.org/web/20200520114546/https://www.eso.org/public/news/eso0846/ |url-status=live }}</ref> and observing the afterglow of the furthest known gamma-ray burst.<ref>{{cite news |date=19 September 2008 |title=NASA's Swift Catches Farthest Ever Gamma-Ray Burst |url=http://www.nasa.gov/mission_pages/swift/bursts/farthest_grb.html |publisher=NASA |access-date=2011-05-04 |archive-date=2020-05-20 |archive-url=https://web.archive.org/web/20200520114546/https://www.nasa.gov/mission_pages/swift/bursts/farthest_grb.html |url-status=live }}</ref>

At the Paranal inauguration in March 1999, names of celestial objects in the [[Mapuche language]] were chosen to replace the technical designations of the four VLT Unit Telescopes (UT1–UT4). An essay contest was prior arranged for schoolchildren in the region concerning the meaning of these names which attracted many entries dealing with the cultural heritage of ESO's host country. A 17-year-old adolescent from [[Chuquicamata]], near [[Calama, Chile|Calama]], submitted the winning essay and was awarded an amateur telescope during the inauguration.<ref>{{cite news |date=6 March 1999 |title=VLT Unit Telescopes Named at Paranal Inauguration |url=http://www.eso.org/public/news/eso9921/ |publisher=ESO |access-date=2011-05-04 |archive-date=2020-05-20 |archive-url=https://web.archive.org/web/20200520114554/https://www.eso.org/public/news/eso9921/ |url-status=live }}</ref> The four unit telescopes, UT1, UT2, UT3 and UT4, are since known as ''Antu'' (sun), ''Kueyen'' (moon), ''Melipal'' (Southern Cross), and ''Yepun'' (Evening Star),<ref>{{cite web |url=http://www.eso.org/public/teles-instr/vlt/vlt-names.html |title=Names of VLT Unit Telescopes |access-date=2011-05-04 |archive-date=2013-08-07 |archive-url=https://web.archive.org/web/20130807063615/http://www.eso.org/public/teles-instr/vlt/vlt-names.html |url-status=live }}</ref> with the latter having been originally mistranslated as "Sirius", instead of "Venus".<ref>{{cite web | url=http://www.eso.org/public/teles-instr/vlt/yepun.html | title=On the Meaning of "YEPUN" | access-date=2011-05-04 | archive-date=2010-11-10 | archive-url=https://web.archive.org/web/20101110110223/http://www.eso.org/public/teles-instr/vlt/yepun.html | url-status=live }}</ref>