Arecibo Observatory

Arecibo Observatory
	The Arecibo Telescope in 2019
Alternative names	National Astronomy and Ionosphere Center
Named after	Arecibo
Organization	University of Central Florida ;
Observatory code	251
Location	Arecibo, Puerto Rico, Caribbean
Coordinates	18°20′39″N 66°45′10″W / 18.34417°N 66.75278°W
Altitude	498 m (1,634 ft)
Website	www.naic.edu
Telescopes	Arecibo 12m radio telescope; Arecibo Telescope ;
	Related media on Commons
	National Astronomy and Ionosphere Center
	U.S. National Register of Historic Places
	U.S. Historic district
Nearest city	Arecibo
Area	118 acres (48 ha)
Built	1963
Architect	Kavanagh, T. C.
Engineer	von Seb, Inc., T. C. Kavanagh of Praeger-Kavanagh, and Severud-Elstad-Krueger Associates
NRHP reference No.	07000525
Added to NRHP	September 23, 2008
	[edit on Wikidata]

The Arecibo Observatory, also known as the National Astronomy and Ionosphere Center (NAIC) and formerly known as the Arecibo Ionosphere Observatory, is an observatory in Barrio Esperanza, Arecibo, Puerto Rico owned by the US National Science Foundation (NSF).

The observatory's main instrument was the Arecibo Telescope, a 305 m (1,000 ft) spherical reflector dish built into a natural sinkhole, with a cable-mount steerable receiver and several radar transmitters for emitting signals mounted 150 m (492 ft) 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. Following two breaks in cables supporting the receiver platform in mid-2020, the NSF decommissioned the telescope. A full collapse of the telescope occurred on December 1, 2020, before either repairs or controlled demolition could be conducted. 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 facility, and a visitor center, which remained operational after the telescope's collapse.^[3]^[4] 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.^[5]

^ "Radio-Radar Telescope Will Probe Solar System". Electrical Engineering. 80 (7): 561. July 1961. doi:10.1109/EE.1961.6433355.
^ National Park Service (October 3, 2008). "Weekly List Actions". Archived from the original on March 29, 2013. Retrieved February 6, 2018.
^ "Arecibo Observatory Telescope Collapses, Ending An Era Of World-Class Research". NPR.org. Archived from the original on December 3, 2020. Retrieved December 3, 2020.
^ "Huge Puerto Rico radio telescope, already damaged, collapses". AP NEWS. December 1, 2020. Archived from the original on April 22, 2021. Retrieved December 3, 2020.
^ "(4337) Arecibo = 1933 HE = 1979 FR3 = 1979 HG2 = 1985 GB". Minor Planet Center. Archived from the original on October 4, 2016. Retrieved June 16, 2022.

[1] "Radio-Radar Telescope Will Probe Solar System". Electrical Engineering. 80 (7): 561. July 1961. doi:10.1109/EE.1961.6433355.

[newlistings20081003-2] National Park Service (October 3, 2008). "Weekly List Actions". Archived from the original on March 29, 2013. Retrieved February 6, 2018.

[3] "Arecibo Observatory Telescope Collapses, Ending An Era Of World-Class Research". NPR.org. Archived from the original on December 3, 2020. Retrieved December 3, 2020.

[4] "Huge Puerto Rico radio telescope, already damaged, collapses". AP NEWS. December 1, 2020. Archived from the original on April 22, 2021. Retrieved December 3, 2020.

[MPC-object-5] "(4337) Arecibo = 1933 HE = 1979 FR3 = 1979 HG2 = 1985 GB". Minor Planet Center. Archived from the original on October 4, 2016. Retrieved June 16, 2022.

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