Cerro Armazones

{{short description|Mountain in Chile}}

{{Infobox mountain

| name = Cerro Armazones

| other_name =

| photo = File:Eagle Eyes over Armazones.jpg

| photo_size =

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| photo_caption = Aerial view of the Cerro Armazones

| elevation_m = 3046

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| range = Cordillera Vicuña Mackenna

| location = Antofagasta Region, Chile

| map = Chile

| range_coordinates =

| map_alt =

| map_caption = Location in Chile

| map_size = 200

| label_position = left

| coordinates = {{coord|24|35|21|S|70|11|32|W|type:mountain_region:CL_scale:100000|format=dms|display=inline,title}}

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}}

Cerro Armazones is a mountain located in the Sierra Vicuña Mackenna of the Chilean Coast Range of the Andes, approximately {{convert|130|km|mi|abbr=on}} southeast of Antofagasta in the Antofagasta Region, Chile. The mountain is situated in an ideal location for optical astronomy due to its 89% cloudless nights annually.{{cite journal |author=Schöck, M. |author2=Els, S. |author3=Riddle, R. |author4=Skidmore, W. |author5=Travouillon, T. |author6=Blum, R. |author7=Bustos, E. |author8=Chanan, G. |author9=Djorgovski, S. G. |author10=Gillett, P. |author11=Gregory, B. |author12=Nelson, J. |author13=Otárola, A. |author14=Seguel, J. |author15=Vasquez, J. |date=1 April 2009 |title=Thirty Meter Telescope Site Testing I: Overview |journal=Publications of the Astronomical Society of the Pacific |volume=121 |issue=878 |pages=384–395 |arxiv=0904.1183 |bibcode=2009PASP..121..384S |doi=10.1086/599287 |author16=Walker, A. |author17=Walker, D. |author18=Wang, L.}} On 26 April 2010, the European Southern Observatory Council selected Cerro Armazones as the site for the planned Extremely Large Telescope (ELT); construction commenced in June 2014.{{cite news |date=26 April 2010 |title=E-ELT Site Chosen |publisher=European Southern Observatory |location=Europe |url=http://www.eso.org/public/news/eso1018/ |access-date=26 April 2010}}{{Cite web |date=2014-06-19 |title=Astronomers to blow top off mountain to make way for world's biggest |url=http://www.independent.co.uk/news/science/european-extremely-large-telescope-to-break-ground-using-dynamite-live-later-today-9548123.html |access-date=28 July 2019 |website=The Independent |language=en}} The first light observation is scheduled for 2027.{{Cite web |last=information@eso.org |title=Facts {{!}} ELT {{!}} ESO |url=https://elt.eso.org/about/facts/ |access-date=11 September 2023 |website=elt.eso.org |language=en}}

Prior to ELT construction, Cerro Armazones had an elevation of {{convert|3,064|m|ft|0}},{{cite map|publisher=Defence Mapping Agency Topographic Center|title=Joint Operations Graphic|url=https://commons.wikimedia.org/wiki/File:Txu-oclc-224571178-sg19-02.jpg|format=JPEG|year=1974|scale=1:250,000|series=1501|page=Sheet SG 19-2|edition=1st}} but the resulting plateau now stands several meters lower after the summit was truncated during construction.

Situated on a neighbouring hill approximately {{convert|1|km|mi|0|abbr=on}} to the southwest and {{convert|230|m|ft|0|abbr=on}} below Cerro Armazones lies the Polish Cerro Armazones Observatory, operated by the Nicolaus Copernicus Astronomical Center of the Polish Academy of Sciences in Warsaw. Observations are conducted by the Araucaria Project.{{cite web |url=https://polishscience.pl/en/polish-astronomical-observatory-opened-in-the-atacama-desert-in-chile/ |title=Polish Astronomical Observatory Opened in the Atacama Desert in Chile |website=Polish Science |publisher=Polish Science |access-date=2024-10-19 |date=2023-11-28 |language=en}}