Editing Arecibo Observatory

{{short description|Radio observatory in Arecibo, Puerto Rico}}
{{about|the observatory complex in general|the former telescope specifically|Arecibo Telescope}}
{{Use mdy dates|date=September 2023}}
{{Infobox observatory
| coordinates          = {{Coord|18|20|39|N|66|45|10|W|type:landmark_region:PR|display=inline,title}}
| embedded             = {{Infobox NRHP
| embed                = yes
| name                 = National Astronomy and Ionosphere Center
| nrhp_type            = hd
| nocat                = yes
| nearest_city         = Arecibo
| mapframe             = yes
| mapframe-frame-coord = {{Coord|18|20|39|N|66|45|10|W|type:landmark_region:PR|display=inline}}
| mapframe-zoom        = 7
| area                 = {{cvt|118|acre|ha}}
| architect            = [[Thomas Christian Kavanagh|Kavanagh, T. C.]]
| engineer             = von Seb, Inc., [[Thomas Christian Kavanagh|T. C. Kavanagh]] of Praeger-Kavanagh, and [[Severud Associates|Severud-Elstad-Krueger Associates]]<ref>{{Cite journal |title=Radio-Radar Telescope Will Probe Solar System |journal=Electrical Engineering |volume=80 |issue=7 |pages=561 |date=July 1961 |doi=10.1109/EE.1961.6433355}}</ref>
| built                = 1963
| architecture         = 
| added                = September 23, 2008<ref name=newlistings20081003>{{cite web |url=http://www.nps.gov/history/nr/listings/20081003.HTM |title=Weekly List Actions |author=National Park Service |date=October 3, 2008 |access-date=February 6, 2018 |archive-date=March 29, 2013 |archive-url=https://web.archive.org/web/20130329001745/http://www.nps.gov/history/nr/listings/20081003.HTM |url-status=live}}</ref>
| visitation_num       = 
| visitation_year      = 
| refnum               = 07000525
| mpsub                = 
}}}}

The '''Arecibo Observatory''', also known as the '''National Astronomy and Ionosphere Center''' ('''NAIC''') and formerly known as the '''Arecibo Ionosphere Observatory''', i<!-- the observatory still exists and will remain functional even without the telescope, do not change to "was"-->s an [[observatory]] in [[Esperanza, Arecibo, Puerto Rico|Barrio Esperanza]], [[Arecibo, Puerto Rico]] owned by the US [[National Science Foundation]] (NSF).

The observatory's main instrument was the [[Arecibo Telescope]], a {{cvt|305|m|ft|sigfig=2}} [[spherical reflector]] [[dish antenna|dish]] built into a natural [[sinkhole]], with a cable-mount steerable receiver and several [[radar]] transmitters for emitting signals mounted {{cvt|150|m|ft|sigfig=3}} above the dish. Completed in 1963, it was the world's largest single-aperture telescope for 53 years, surpassed in July 2016 by the [[Five-hundred-meter Aperture Spherical Telescope]] (FAST) in China. On August 10 and November 6, 2020, two of the receiver's support cables broke and the NSF announced that it would decommission the telescope. The telescope collapsed on December 1, 2020.<ref name="NASEM">{{cite report|title=Failure Analysis of the Arecibo Observatory 305-Meter Telescope Collapse.|date=2024|publisher=The National Academies Press|author=National Academies of Sciences, Engineering, and Medicine|doi=10.17226/26982}}</ref> In 2022, the NSF announced the telescope will not be rebuilt, with an educational facility to be established on the site.

The observatory also includes a smaller [[radio telescope]], a [[Lidar|LIDAR]] facility, and a visitor center, which remained operational after the telescope's collapse.<ref>{{Cite web |title=Arecibo Observatory Telescope Collapses, Ending An Era Of World-Class Research |url=https://www.npr.org/2020/12/01/940767001/arecibo-observatory-telescope-collapses-ending-an-era-of-world-class-research |access-date=2020-12-03 |website=NPR.org |language=en |archive-date=December 3, 2020 |archive-url=https://web.archive.org/web/20201203161440/https://www.npr.org/2020/12/01/940767001/arecibo-observatory-telescope-collapses-ending-an-era-of-world-class-research |url-status=live }}</ref><ref>{{Cite web |date=2020-12-01 |title=Huge Puerto Rico radio telescope, already damaged, collapses |url=https://apnews.com/article/technology-arecibo-observatory-puerto-rico-science--0da6abb251f455977bf0c752348e712e |access-date=2020-12-03 |website=AP NEWS |archive-date=April 22, 2021 |archive-url=https://web.archive.org/web/20210422013836/https://apnews.com/article/technology-arecibo-observatory-puerto-rico-science--0da6abb251f455977bf0c752348e712e |url-status=live }}</ref> The asteroid [[4337 Arecibo]] is named after the observatory by [[Steven J. Ostro]], in recognition of the observatory's contributions to the characterization of Solar System bodies.<ref name="MPC-object">{{cite web |title=(4337) Arecibo = 1933 HE = 1979 FR3 = 1979 HG2 = 1985 GB |url=https://minorplanetcenter.net/db_search/show_object?utf8=%E2%9C%93&object_id=4337 |url-status=live |archive-url=https://web.archive.org/web/20161004175246/http://www.minorplanetcenter.net/db_search/show_object?utf8=%E2%9C%93&object_id=4337 |archive-date=4 October 2016 |publisher=Minor Planet Center |access-date=16 June 2022}}</ref>

==History==
{{see also|Arecibo Telescope#History|l1=History of the Arecibo Telescope}}
In the 1950s, the [[United States Department of Defense]] (DoD)'s [[Advanced Research Projects Agency]] (ARPA) was seeking a means to detect missiles in Earth's [[ionosphere]]. On November 6, 1959, [[Cornell University]] entered into a contract with ARPA to carry out development studies for a large-scale ionospheric radar probe.<ref>{{Cite web |title=Arecibo Observatory |url=https://www.darpa.mil/about-us/timeline/arecibo-observatory |access-date=September 28, 2024 |website=darpa.mil}}</ref> The Arecibo Telescope was consequently built to study the ionosphere as well as to serve as a general-purpose [[radio telescope]]. Construction of the telescope was started in September 1960. The telescope and supporting observatory were formally opened as the Arecibo Ionospheric Observatory on November 1, 1963.<ref name="congrecord">{{cite magazine |url=https://www.govinfo.gov/content/pkg/CREC-2003-10-31/pdf/CREC-2003-10-31.pdf |title=The 40th Anniversary of the Arecibo Observatory |page=E2181 |first=Aníbal |last=Acevedo-Vila |date=October 30, 2003 |access-date=January 14, 2021 |magazine=[[Congressional Record]] |volume=149 |issue=156 |archive-date=August 21, 2021 |archive-url=https://web.archive.org/web/20210821191118/https://www.govinfo.gov/content/pkg/CREC-2003-10-31/pdf/CREC-2003-10-31.pdf |url-status=live }}</ref>

DoD transferred the observatory to the [[National Science Foundation]] on October 1, 1969. NSF appointed Cornell University to manage the observatory. By September 1971, NSF had renamed the observatory the National Astronomy and Ionosphere Center (NAIC) and had made it a [[federally funded research and development center]] (FFRDC).<ref name="congrecord"/> [[NASA]] began contributing funds to the observatory alongside NSF for its planetary radar mission.<ref name="SP4218">{{cite web |last=Butrica |first=Andrew J. |url=https://history.nasa.gov/SP-4218/sp4218.htm |title=NASA SP-4218: To See the Unseen – A History of Planetary Radar Astronomy |publisher=NASA |date=1996 |access-date=August 6, 2014 |archive-url=https://web.archive.org/web/20071101060112/https://history.nasa.gov/SP-4218/sp4218.htm |archive-date=November 1, 2007}}</ref>

In the early 2000s, NASA eliminated funding for the Arecibo Observatory.<ref>{{cite web |url=http://www.space.com/scienceastronomy/astronomy/arecibo_cuts_011220.html |title=NASA Trims Arecibo Budget, Says Other Organizations Should Support Asteroid Watch |access-date=July 8, 2008 |author=Robert Roy Britt |date=December 20, 2001 |work=Space.com |publisher=Imaginova |url-status=dead |archive-url=https://web.archive.org/web/20081205190409/http://www.space.com/scienceastronomy/astronomy/arecibo_cuts_011220.html |archive-date=December 5, 2008}}</ref> In 2006, NSF indicated that it would reduce funding for the observatory, and decommission it if other funding could not be found.<ref>{{cite news |last=Weiss |first=Rick Weiss |title=Radio Telescope And Its Budget Hang in the Balance |url=https://www.washingtonpost.com/wp-dyn/content/article/2007/09/08/AR2007090801654.html?hpid=moreheadlines |newspaper=The Washington Post |location=Arecibo, Puerto Rico |page=A01 |date=September 9, 2007 |access-date=July 8, 2008 |quote=The cash crunch stems from an NSF ''senior review'' completed last November. Its $200&nbsp;million astronomy division, increasingly committed to ambitious new projects, but long hobbled by flat Congressional budgets, was facing a deficit of at least $30&nbsp;million by 2010. |archive-date=November 6, 2012 |archive-url=https://web.archive.org/web/20121106141623/http://www.washingtonpost.com/wp-dyn/content/article/2007/09/08/AR2007090801654.html?hpid=moreheadlines |url-status=live}}</ref> Academics and politicians lobbied to stave off its closure, and NASA recommitted funding in 2011 for study of [[near-earth object]]s.<ref>{{cite web| archive-url=https://web.archive.org/web/20121006232826/http://science.nasa.gov/media/medialibrary/2010/04/27/NASAsupport_to_Planetary_Radar.pdf |url=http://science.nasa.gov/media/medialibrary/2010/04/27/NASAsupport_to_Planetary_Radar.pdf| title=NASA Support to Planetary Radar|date= April 27, 2010|archive-date=Oct 6, 2012}}</ref> In 2011, NSF delisted Arecibo as an FFRDC, which allowed the observatory to seek funding from a wider variety of sources; the agency also replaced Cornell as the site operator with a team led by [[SRI International]].<ref>{{cite web |url=https://www.nsf.gov/funding/pgm_summ.jsp?pims_id=5652 |title=Management and Operation of the NAIC|archive-url=https://web.archive.org/web/20180303050341/https://www.nsf.gov/funding/pgm_summ.jsp?pims_id=5652 |archive-date=March 3, 2018| access-date= April 6, 2013}}</ref>

Damage to the telescope by 2017's [[Hurricane Maria]] led NSF again to suggest closing the observatory.<ref>{{cite news |url=https://www.washingtonpost.com/news/speaking-of-science/wp/2017/09/20/arecibo-observatory-puerto-ricos-famous-radio-telescope-is-battered-by-hurricane-maria/ |title=Arecibo Observatory, Puerto Rico's famous telescope, is battered by Hurricane Maria |last=Kaplan |first=Sarah |newspaper=[[The Washington Post]] |date=September 22, 2017 |access-date=September 24, 2017 |archive-date=September 21, 2017 |archive-url=https://web.archive.org/web/20170921090157/https://www.washingtonpost.com/news/speaking-of-science/wp/2017/09/20/arecibo-observatory-puerto-ricos-famous-radio-telescope-is-battered-by-hurricane-maria/ |url-status=live}}</ref> A consortium led by the [[University of Central Florida]] (UCF) proposed to manage the observatory and cover much of the operations and maintenance costs, and in 2018, NSF made UCF's consortium the new site operators,<ref>{{cite news |url=https://www.science.org/content/article/iconic-arecibo-radio-telescope-saved-university-consortium |title=Iconic Arecibo radio telescope saved by university consortium |work=[[Science (journal)|Science]] |date=February 22, 2018 |url-status=live |access-date=March 3, 2018 |archive-url=https://web.archive.org/web/20180304172439/http://www.sciencemag.org/news/2018/02/iconic-arecibo-radio-telescope-saved-university-consortium |archive-date=March 4, 2018}}</ref><ref name="ucf">{{cite press release |url=https://today.ucf.edu/ucf-led-consortium-manage-arecibo-observatory-puerto-rico/ |title=UCF-led Consortium to Manage Arecibo Observatory in Puerto Rico |publisher=[[UCF Today]] |date=February 22, 2018 |access-date=April 18, 2018 |archive-date=April 19, 2018 |archive-url=https://web.archive.org/web/20180419120618/https://today.ucf.edu/ucf-led-consortium-manage-arecibo-observatory-puerto-rico/ |url-status=live}}</ref> though no specific actions or funding were announced.

On August 6, 2020, an auxiliary cable broke on the telescope, followed by a main cable on November 7.  The NSF announced that they would decommission the telescope through controlled demolition, but that the other facilities on the observatory would remain operational. Before demolition could occur, remaining support cables from one tower rapidly failed in the morning of December 1, 2020, causing the instrument platform to crash through the dish, shearing off the tops of the support towers, and partially damaging some of the other buildings, though with no injuries.<ref name="guardian collapsed"/><ref name="NASEM"/> NSF officials said in 2020 that they aimed to have the other observatory facilities operational as soon as possible and were considering rebuilding a new telescope instrument in its place.<ref name="verge decommission">{{cite web |url=https://www.theverge.com/2020/11/19/21575025/arecibo-observatory-puerto-rico-decommission-structural-collapse-cable-break |title=Facing collapse, the famed Arecibo Observatory will be demolished |first=Loren |last=Grush |date=November 19, 2020 |access-date=November 19, 2020 |work=[[The Verge]] |archive-date=November 19, 2020 |archive-url=https://web.archive.org/web/20201119165655/https://www.theverge.com/2020/11/19/21575025/arecibo-observatory-puerto-rico-decommission-structural-collapse-cable-break |url-status=live}}</ref> However, in 2022, the NSF announced the telescope will not be rebuilt but an educational facility would be established on the site.<ref>{{Cite journal |last=Witze |first=Alexandra |date=2022-10-14 |title=Renowned Arecibo telescope won't be rebuilt — and astronomers are heartbroken |journal=Nature |volume=610 |issue=7933 |pages=618–619 |language=en |doi=10.1038/d41586-022-03293-4 |pmid=36241884 |bibcode=2022Natur.610..618W |s2cid=252903742 |doi-access=}}</ref> The following year, NSF picked a consortium of universities{{mdash}}[[Cold Spring Harbor Laboratory]] in New York; the [[University of Maryland, Baltimore County]]; the [[University of Puerto Rico, Río Piedras Campus]] in San Juan; and the [[Universidad del Sagrado Corazón|University of the Sacred Heart]], also in San Juan{{mdash}}to set up and run an education center called [https://www.areciboc3.org/ Arecibo C3] (Arecibo Center for Culturally Relevant and Inclusive Science Education, Computational Skills, and Community Engagement).<ref>{{Cite journal |last=Oza |first=Anil |date=2023-09-26 |title=A new era for Arecibo: legendary observatory begins next phase |url=https://www.nature.com/articles/d41586-023-03021-6 |journal=Nature |volume=622 |issue=7981 |pages=19–20 |language=en |doi=10.1038/d41586-023-03021-6 |pmid=37759120 |bibcode=2023Natur.622...19O |s2cid=263113097 |access-date=September 28, 2023 |archive-date=September 28, 2023 |archive-url=https://web.archive.org/web/20230928135656/https://www.nature.com/articles/d41586-023-03021-6 |url-status=live }}</ref><ref>{{cite web |title=Arecibo C3 |url=https://www.areciboc3.org/ |publisher=U.S. National Science Foundation |access-date=10 December 2024}}</ref>

==Facilities==
===Arecibo Telescope===
{{Main|Arecibo Telescope}}
The observatory's main feature was its large [[Arecibo Telescope|radio telescope]], whose main collecting dish was an inverted [[spherical dome]] {{convert|305|m|ft|sigfig=3|order=flip}} in diameter with an {{convert|265|m|ft|sigfig=3|adj=on|order=flip}} [[radius of curvature]],<ref name="arecibo-multifeed">{{cite journal |last1=Goldsmith |first1=P. F. |last2=Baker |first2=L. A. |last3=Davis |first3=M. M. |last4=Giovanelli |first4=R. |title=Multi-feed Systems for the Arecibo Gregorian |journal=Astronomical Society of the Pacific Conference Series |date=1995 |volume=75 |bibcode=1995ASPC...75...90G |pages=90–98}}</ref> constructed inside a [[karst]] [[sinkhole]].<ref>{{cite web |url=https://www.naic.edu/ao/telescope-description |title=Telescope Description |publisher=[[National Astronomy and Ionosphere Center]] |access-date=November 20, 2020 |archive-date=November 20, 2020 |archive-url=https://web.archive.org/web/20201120035144/https://www.naic.edu/ao/telescope-description |url-status=live}}</ref> The dish's surface was made of 38,778 perforated aluminum panels, each about {{convert|1|by|2|m|ft|0|order=flip}}, supported by a mesh of steel cables.<ref name="arecibo-multifeed"/> The ground beneath supported shade-tolerant vegetation.<ref>{{cite web |url=https://www.nsf.gov/mps/ast/env_impact_reviews/arecibo/eis/DEIS.pdf |website=nsf.gov |publisher=NSF |page=66 |title=Environmental Impact Statement for the Arecibo Observatory Arecibo, Puerto Rico (Draft) |quote=At the Arecibo Observatory, a mix of shade-tolerant species have colonized the area beneath the 305-meter radio telescope dish. |access-date=November 23, 2020 |archive-date=December 16, 2020 |archive-url=https://web.archive.org/web/20201216232114/https://www.nsf.gov/mps/ast/env_impact_reviews/arecibo/eis/DEIS.pdf |url-status=live }}</ref>

Since its completion in November 1963, the Telescope had been used for [[radar astronomy]] and [[radio astronomy]], and had been part of the [[Search for extraterrestrial intelligence]] (SETI) program. It was also used by NASA for [[Near-Earth object]] detection. Since around 2006, NSF funding support for the telescope had waned as the Foundation directed funds to newer instruments, though academics petitioned to the NSF and Congress to continue support for the telescope. Numerous hurricanes, including [[Hurricane Maria]], had damaged parts of the telescope, straining the reduced budget.

Two cable breaks, one in August 2020 and a second in November 2020, threatened the structural integrity of the support structure for the suspended platform and damaged the dish. The NSF determined in November 2020 that it was safer to decommission the telescope rather than to try to repair it, but the telescope collapsed before a controlled demolition could be carried out. The remaining support cables from one tower failed around 7:56&nbsp;a.m. local time on December 1, 2020, causing the receiver platform to fall into the dish and collapsing the telescope.<ref name="guardian collapsed">{{cite news |date=1 December 2020 |title=Giant Arecibo radio telescope collapses in Puerto Rico |work=[[The Guardian]] |agency=[[Associated Press]] |url=https://www.theguardian.com/world/2020/dec/01/arecibo-radio-telescope-collapses-puerto-rico |access-date=1 December 2020 |archive-date=December 25, 2020 |archive-url=https://web.archive.org/web/20201225005405/https://www.theguardian.com/world/2020/dec/01/arecibo-radio-telescope-collapses-puerto-rico |url-status=live }}</ref><ref name="APNews1Dec2020">{{cite news |last1=Coto |first1=Danica |title=Huge Puerto Rico radio telescope, already damaged, collapses |url=https://apnews.com/article/technology-arecibo-observatory-puerto-rico-science--0da6abb251f455977bf0c752348e712e |access-date=5 December 2020 |work=AP NEWS |date=1 December 2020 |archive-date=April 22, 2021 |archive-url=https://web.archive.org/web/20210422013836/https://apnews.com/article/technology-arecibo-observatory-puerto-rico-science--0da6abb251f455977bf0c752348e712e |url-status=live }}</ref>

NASA led an extensive failure investigation and reported the findings,<ref name="collapsed">{{cite news |date=30 June 2021 |title=Arecibo Observatory Auxiliary M4N Socket Termination Failure Investigation |url=https://ntrs.nasa.gov/citations/20210017934 |website=[[NASA]] |access-date=July 1, 2021 |archive-date=July 3, 2021 |archive-url=https://web.archive.org/web/20210703000546/https://ntrs.nasa.gov/citations/20210017934 |url-status=live }}</ref> along with a technical bulletin with industry recommendations.<ref>{{Cite web |date=2 August 2021 |title=NASA Engineering and Safety Center Technical Bulletin No. 21-05, Industry Recommendations from Arecibo Observatory Zinc Spelter Socket Joint Failure Analysis |url=https://www.nasa.gov/sites/default/files/atoms/files/tb_21-05_arecibo_failure_analysis_080221_final.pdf |url-status=live |website=[[NASA]] |archive-url=https://web.archive.org/web/20220103160714/https://www.nasa.gov/sites/default/files/atoms/files/tb_21-05_arecibo_failure_analysis_080221_final.pdf |archive-date=2022-01-03}}</ref> The investigation concluded that "a combination of low socket [[design margin]] and a high percentage of sustained loading revealed an unexpected vulnerability to [[Creep (deformation)|zinc creep]] and environments, resulting in long-term cumulative damage and progressive zinc/wire failure".

===Additional telescopes===
The Arecibo Observatory also has other facilities beyond the main telescope, including a {{convert|12|m|ft|sp=us|adj=on}} radio telescope intended for [[very-long-baseline interferometry]] (VLBI) with the main telescope;<ref>{{cite arXiv |last1=Roshi |first1=D. Anish |last2=Anderson |first2=L. D. |last3=Araya |first3=E. |last4=Balser |first4=D. |last5=Brisken |first5=W. |last6=Brum |first6=C. |last7=Campbell |first7=D. |last8=Chatterjee |first8=S. |last9=Churchwell |first9=E. |last10=Condon |first10=J. |last11=Cordes |first11=J. |last12=Cordova |first12=F. |last13=Fernandez |first13=Y. |last14=Gago |first14=J. |last15=Ghosh |first15=T. |last16=Goldsmith |first16=P. F. |last17=Heiles |first17=C. |last18=Hickson |first18=D. |last19=Jeffs |first19=B. |last20=Jones |first20=K. M. |last21=Lautenbach |first21=J. |last22=Lewis |first22=B. M. |last23=Lynch |first23=R. S. |last24=Manoharan |first24=P. K. |last25=Marshall |first25=S. |last26=Minchin |first26=R. |last27=Palliyaguru |first27=N. T. |last28=Perera |first28=B. B. P. |last29=Perillat |first29=P. |last30=Pinilla-Alonso |first30=N. |last31=Pisano |first31=D. J. |last32=Quintero |first32=L. |last33=Raizada |first33=S. |last34=Ransom |first34=S. M. |last35=Fernandez-Rodriguez |first35=F. O. |last36=Salter |first36=C. J. |last37=Santos |first37=P. |last38=Sulzer |first38=M. |last39=Taylor |first39=P. A. |last40=Venditti |first40=F. C. F. |last41=Venkataraman |first41=A. |last42=Virkki |first42=A. K. |last43=Wolszczan |first43=A. |last44=Womack |first44=M. |last45=Zambrano-Marin |first45=L. F. |title=Astro2020 Activities and Projects White Paper: Arecibo Observatory in the Next Decade |date=13 July 2019 |class=astro-ph.IM |eprint=1907.06052}}</ref> and a LIDAR facility<ref>{{cite web |title=NSF begins planning for decommissioning of Arecibo Observatory's 305-meter telescope due to safety concerns [News Release 20-010] |url=https://www.nsf.gov/news/news_summ.jsp?cntn_id=301674 |website=www.nsf.gov |access-date=November 19, 2020 |language=en |archive-date=November 19, 2020 |archive-url=https://web.archive.org/web/20201119163316/https://www.nsf.gov/news/news_summ.jsp?cntn_id=301674 |url-status=live}}</ref> whose research has continued since the main telescope's collapse.

{{Wide image|Panorama arecibo telescope from observation deck.jpg|800px|The Arecibo Radio Telescope as viewed from the observation deck, October 2013}}

=== Ángel Ramos Foundation Visitor Center ===
[[Image:Arecibo_Observatory,_sign_at_entrance_gate.jpg|thumb|right|Logo of the observatory at the entrance gate]]

Opened in 1997, the Ángel Ramos Foundation Visitor Center features interactive exhibits and displays about the operations of the radio telescope, [[astronomy]] and [[atmospheric sciences]].<ref>[http://www.naic.edu/general/index.php?option=com_content&view=article&id=192&Itemid=638 Visitor Center information] {{webarchive |url=https://web.archive.org/web/20131104160330/http://www.naic.edu/general/index.php?option=com_content&view=article&id=192&Itemid=638 |date=November 4, 2013 }}</ref> The center is named after the financial foundation that honors [[Ángel Ramos (industrialist)|Ángel Ramos]], owner of the ''[[El Mundo (Puerto Rico)|El Mundo]]'' newspaper and founder of [[Telemundo]]. The Foundation provided half of the funds to build the Visitor Center, with the remainder received from private donations and [[Cornell University]].

The center, in collaboration with the Caribbean Astronomical Society,<ref>{{cite web |url=http://www.sociedadastronomia.com/ |title=Sociedad de Astronomia del Caribe |website=www.sociedadastronomia.com |access-date=May 5, 2014 |archive-date=May 5, 2014 |archive-url=https://web.archive.org/web/20140505181129/http://www.sociedadastronomia.com/ |url-status=live}}</ref> hosts a series of Astronomical Nights throughout the year, which feature diverse discussions regarding [[exoplanet]]s, astronomical phenomena, and discoveries (such as [[Comet ISON]]). The purposes of the center are to increase public interest in astronomy, the observatory's research successes, and space endeavors.

== List of directors ==
Source(s):<ref>{{cite journal |last1=Altschuler |first1=Daniel |last2=Salter |first2=Chris |title=Early history of Arecibo Observatory |journal=Physics Today |date=June 2014 |volume=67 |issue=6 |pages=12 |doi=10.1063/PT.3.2402 |bibcode=2014PhT....67f..12A |doi-access=}}</ref>{{Additional citation needed|date=November 2020}}
{{div col|colwidth=17em}}
* 1960–1965: [[William E. Gordon]]
* 1965–1966: John W. Findlay
* 1966–1968: [[Frank Drake]]
* 1968–1971: [[Gordon Pettengill]]
* 1971–1973: [[Tor Hagfors]]<ref>{{Cite web |date=January 24, 2007 |title=Tor Hagfors, astronomy professor and Arecibo pioneer, dies at age 76 |url=https://news.cornell.edu/stories/2007/01/tor-hagfors-astronomy-professor-and-arecibo-pioneer-dies-76 |access-date=November 20, 2020 |website=Cornell Chronicle |language=en |archive-date=November 20, 2020 |archive-url=https://web.archive.org/web/20201120204516/https://news.cornell.edu/stories/2007/01/tor-hagfors-astronomy-professor-and-arecibo-pioneer-dies-76 |url-status=live}}</ref>
* 1973–1982: Harold D. Craft Jr.<ref>{{Cite web |last=Christiansen |first=Jen |title=Pop Culture Pulsar: The Science Behind Joy Division's Unknown Pleasures Album Cover |url=https://blogs.scientificamerican.com/sa-visual/pop-culture-pulsar-the-science-behind-joy-division-s-unknown-pleasures-album-cover/ |access-date=November 20, 2020 |website=Scientific American Blog Network |language=en |archive-date=November 12, 2020 |archive-url=https://web.archive.org/web/20201112023018/https://blogs.scientificamerican.com/sa-visual/pop-culture-pulsar-the-science-behind-joy-division-s-unknown-pleasures-album-cover/ |url-status=live}}</ref>
* 1982–1987: [[Donald B. Campbell]]
* 1987–1988: [[Riccardo Giovanelli]]
* 1988–1992: Michael M. Davis
* 1992–2003: [[Daniel R. Altschuler]]
* 2003–2006: [[Sixto González|Sixto A. González]]
* 2006–2007: Timothy H. Hankins
* 2007–2008: Robert B. Kerr<ref name="Watson2015">{{cite journal |last1=Watson |first1=Traci |title=Arecibo Observatory director quits after funding row |journal=Nature |date=November 2015 |volume=527 |issue=7577 |pages=142–143 |doi=10.1038/nature.2015.18745 |pmid=26560275 |bibcode=2015Natur.527..142W |doi-access=free}}</ref>
* 2008–2011: Michael C. Nolan
* 2011–2015: Robert B. Kerr<ref name="Watson2015"/>
* 2016–2022: Francisco Córdova
* 2022–2023: Olga Figueroa
* Arecibo C3, A STEM Education Center : 2023–present: [[Wanda Díaz-Merced|Wanda Liz Díaz Merced]]<ref>{{cite web |url=https://new.nsf.gov/news/nsf-announces-over-5m-funding-create-new-stem |title=NSF announces over $5M in funding to create new STEM education and research center at the Arecibo Observatory site |date=September 25, 2023 |access-date=2023-10-26 |archive-date=October 26, 2023 |archive-url=https://web.archive.org/web/20231026144348/https://new.nsf.gov/news/nsf-announces-over-5m-funding-create-new-stem |url-status=live }}</ref>{{div col end}}

== See also ==
{{Portal|Astronomy|Puerto Rico|National Register of Historic Places}}
<!-- Please keep entries in alphabetical order & add a short description [[WP:SEEALSO]] -->
{{div col|colwidth=25em}}
* [[Air Force Research Laboratory]] (US)
* [[Atacama Large Millimeter Array]] (Chile)
* [[Five-hundred-meter Aperture Spherical Telescope]] (China)
* [[List of radio telescopes]]
* [[RATAN-600]] (Russia)
* [[UPRM Planetarium]], projection room in the University of Puerto Rico
{{div col end}}
<!-- please keep entries in alphabetical order -->

== References ==
{{Reflist}}

== Further reading ==
{{div col|colwidth=30em|small=yes}}
* {{cite book |title=The Arecibo Observatory: A History of Innovation and Discovery|date=2024|isbn=978-3-031-75225-4|doi=10.1007/978-3-031-75225-4|publisher=Springer |last=Campbell| first=Donald B.}}
* {{cite news |title=Research rockets, including an experiment from Cornell, are scheduled for launch into the ionosphere next year from Puerto Rico |date=November 14, 1997 |publisher=Cornell University |last=Friedlander |first=Blaine |url=https://news.cornell.edu/stories/1997/11/research-rockets-including-experiment-cornell-are-scheduled-launch-ionosphere-next |ref=none}}
* {{cite news |title=Activists protest US Navy radar project |date=March 3, 1998 |last=Ruiz |first=Carmelo |publisher=Global Network Against Weapons and Nuclear Power in Space |url=http://www.globenet.free-online.co.uk/actions/prico2.htm |archive-url=https://web.archive.org/web/20010501002404/http://www.globenet.free-online.co.uk/actions/prico2.htm |url-status=dead |archive-date=May 1, 2001 |ref=none}}<!-- Sorry, but this is the most reputable source I can find, even though it is a pressure group.-->
* {{cite web |url=http://www.planetary.org/programs/projects/advocacy_and_education/space_advocacy/20080703.html |title=Budget Cuts Threaten Arecibo Observatory |author=Amir Alexander |publisher=The Planetary Society |date=July 3, 2008 |url-status=dead |archive-url=https://web.archive.org/web/20080721105122/http://www.planetary.org/programs/projects/advocacy_and_education/space_advocacy/20080703.html |archive-date=July 21, 2008 |ref=none}}
* {{cite web |url=http://www.eurekalert.org/pub_releases/2008-06/cuc-ajg061008.php |title=Arecibo joins global network to create {{convert|6000|mi|km |adj=on}} telescope |author=Blaine Friedlander |publisher=EurekAlert |date=June 10, 2008 |ref=none}}
* {{cite web |url=http://www.news.cornell.edu/stories/June08/arecibo.clintons.html |title=Clintons (minus Hillary) visit Arecibo; former president urges more federal funding for basic sciences |author=Lauren Gold |publisher=Cornell university |date=June 5, 2008 |ref=none}}
* {{cite news |url=https://www.nytimes.com/2007/12/25/science/25obtele.html |title=Arecibo Radio Telescope Is Back in Business After 6-Month Spruce-Up |author=Henry Fountain |work=[[The New York Times]] |date=December 25, 2007 |ref=none}}
*[http://www.nps.gov/history/nr/feature/weekly_features/IonosphereCenter.pdf Entry into the National Register of Historic Places]
* {{cite journal |url=http://resolver.caltech.edu/CaltechAUTHORS:20091231-110730776 |first1=Marshall H. |last1=Cohen |date=2009 |title=Genesis of the 1000-foot Arecibo Dish |journal=Journal of Astronomical History and Heritage |volume=12 |issue=2 |pages=141–152 |doi=10.3724/SP.J.1440-2807.2009.02.06 |bibcode=2009JAHH...12..141C |s2cid=18990068 |ref=none}}
* {{cite journal |first1=Daniel R. |last1=Altschuler |first2=Christopher J. |last2=Salter |title=The Arecibo Observatory: Fifty astronomical years |journal=Physics Today |volume=66 |number=11 |page=43 |doi=10.1063/PT.3.2179 |date=2013 |bibcode=2013PhT....66k..43A |ref=none}}
https://blogs.iu.edu/sciu/2021/07/03/arecibos-50-years-of-discoveries/

{{div col end}}

== External links ==
{{Commons category|Arecibo Observatory}}
* {{Official website|www.naic.edu}}

{{Radio-astronomy}}
{{NRHP in Arecibo, Puerto Rico}}
{{Extraterrestrial life}}
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[[Category:Astronomical observatories in Puerto Rico]]
[[Category:Government buildings completed in 1963]]
[[Category:Historic districts on the National Register of Historic Places in Puerto Rico]]
[[Category:Historic Mechanical Engineering Landmarks]]
[[Category:Museums in Arecibo, Puerto Rico]]
[[Category:National Science Foundation]]
[[Category:Radio telescopes]]
[[Category:Science museums in Puerto Rico]]
[[Category:Search for extraterrestrial intelligence]]
[[Category:University museums in Puerto Rico]]
[[Category:Advanced Research Projects Agency]]
[[Category:National Register of Historic Places in Arecibo, Puerto Rico]]
[[Category:Educational buildings on the National Register of Historic Places in Puerto Rico]]
[[Category:University of Central Florida]]