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Arecibo Radio Telescope

Aerial view of the Observatory

Organization SRI International

USRA

UMET

Location Arecibo, Puerto Rico, USA

Wavelength electromagnetic spectrum: (3.00

cm to 1.00 meter)

Built completed in 1963

Telescope style spherical reflector

Diameter 1,000 ft (300 m)

Collecting area 73,000 square metres

(790,000 sq ft)

Mounting semi-transit telescope: fixed

primary with secondary

(Gregorian reflector) and a delay-

line feed, each of which moves on

tracks to point to different parts of

the sky.

Dome none

Arecibo ObservatoryFrom Wikipedia, the free encyclopedia

The Arecibo Observatory is aradio telescope in the municipalityof Arecibo, Puerto Rico, USA. Thisobservatory is operated by SRIInternational, USRA and UMET,under cooperative agreement withthe National Science Foundation

(NSF).[2][3] This observatory isalso called the National Astronomyand Ionosphere Center, although"NAIC" refers to both theobservatory and the staff that

operates it.[4]

The observatory's 1,000 ft (305 m)radio telescope is the world'slargest single-aperture telescope. Itis used in three major areas ofresearch: radio astronomy,aeronomy, and radar astronomy.Scientists who want to use thetelescope submit proposals that areevaluated by an independentscientific board.

The telescope has madeappearances in motion picture andtelevision productions and got morerecognition in 1999 when it began tocollect data for the SETI@homeproject. It has been listed on theAmerican National Register ofHistoric Places beginning in

2008.[1][5] It was the featured listing

Coordinates: 18°20′39″N 66°45′10″W

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Website www.naic.edu

(http://www.naic.edu)

National Astronomy and

Ionosphere Center

U.S. National Register of Historic

Places

U.S. Historic district

Coordinates: 18°20′39″N

66°45′10″W

Area: 118 acres

(480,000 m2)

Architect: Gordon,

William E;

Kavanaugh,

T.C.

Governing body: Federal

NRHP Reference#:07000525

Added to NRHP: September

23, 2008[1]

in the National Park Service's

weekly list of October 3, 2008.[6]

The center was named an IEEE

Milestone in 2001.[7]

Contents

1 Ángel Ramos Foundation Visitor Center2 General information3 Design and architecture4 Research and discoveries

4.1 The Arecibo message4.2 Other uses

5 Funding issues6 In popular culture7 Arecibo Observatory Directors8 See also9 References10 Further reading11 External links

Ángel Ramos Foundation VisitorCenter

Opened in 1997, the Ángel Ramos FoundationVisitor Center features interactive exhibits anddisplays about the operations of the radio telescope,astronomy, and atmospheric science. The center is named after the financial foundationthat honors Ángel Ramos, the owner of the El Mundo newspaper and the founder ofTelemundo. This foundation provided half of the money to build the visitors center,with the rest coming from private donations and from Cornell University. It is normallyopen Wednesday-Sunday, with additional opening hours on many holidays and schoolbreaks. As of 2012, the admission fee is $10.00 for adults and $6.00 for seniors and

children under 10.[8]

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General information

The main collecting dish is 1,000 ft (305 m) in diameter, constructed inside the

depression left by a karst sinkhole.[9] It contains the largest curved focusing dish on

Earth, giving Arecibo the largest electromagnetic-wave-gathering capacity.[10] The dishsurface is made of 38,778 perforated aluminum panels, each about 3 by 6 feet (1 by 2m), supported by a mesh of steel cables.

The telescope has three radar transmitters, with effective isotropic radiated powers of20 TW at 2380 MHz, 2.5 TW (pulse peak) at 430 MHz, and 300 MW at 47 MHz.

The telescope is a spherical reflector of radius 870 ft, not a parabolic reflector. To aimthe telescope, the receiver is moved to intercept signals reflected from differentdirections by the spherical dish surface. A parabolic mirror would have varyingastigmatism when the receiver is off the focal point, but the error of a spherical mirroris the same in every direction.

The receiver is on a 900-ton platform suspended 150 m (500 ft) above the dish by 18cables running from three reinforced concrete towers, one 110 m (365 ft) high and theother two 80 m (265 ft) high, placing their tops at the same elevation. The platform hasa 93-meter-long rotating bow-shaped track, called the azimuth arm, carrying thereceiving antennas and secondary and tertiary reflectors. This allows the telescope toobserve any region of the sky in a forty-degree cone of visibility about the local zenith(between −1 and 38 degrees of declination). Puerto Rico's location near the equatorallows Arecibo to view all of the planets in the Solar System, though the round triplight time to objects beyond Saturn is longer than the time the telescope can track it,preventing radar observations of more distant objects.

Design and architecture

The Arecibo telescope was built between mid-1960 and November 1963, by WilliamE. Gordon of Cornell University, who intended to use it to study Earth's

ionosphere.[11][12][13] Originally, a fixed parabolic reflector was envisioned, pointingin a fixed direction with a 150 m (500 ft) tower to hold equipment at the focus. Thisdesign would have limited its use in other areas of research, such as planetary scienceand radio astronomy, which require the ability to point at different positions in the skyand to track those positions for an extended period as Earth rotates. Ward Low of the

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A detailed view of the beam-

steering mechanism and some

antennas. The triangular

platform at the top is fixed,

and the azimuth arm rotates

beneath it. To the left is the

Gregorian sub-reflector, and

to the right is the 96-foot-long

(29 m) line feed tuned to 430

MHz. Just visible at the upper

right is part of the rectangular

waveguide that brings the 2.5

MW 430 MHz radar

transmitter's signal up to the

focal region.

Advanced Research Projects Agency (ARPA) pointed out this flaw, and put Gordon intouch with the Air Force Cambridge Research Laboratory (AFCRL) in Boston,Massachusetts, where one group headed by Phil Blacksmith was working on sphericalreflectors and another group was studying the propagation of radio waves in andthrough the upper atmosphere. Cornell University proposed the project to ARPA inmid-1958 and a contract was signed between the AFCRL and the University inNovember 1959. Cornell University and Zachary Sears published a request forproposals (RFP) asking for a design to support a feedmoving along a spherical surface 435 feet (133 m)above the stationary reflector. The RFP suggested atripod or a tower in the center to support the feed. AtCornell University on the day the project for the designand construction of the antenna was announced,Gordon had also envisioned a 435 ft (133 m) towercentered in the 1,000 ft (300 m) reflector to support thefeed.

George Doundoulakis, who directed research atGeneral Bronze Corporation in Garden City, NewYork, along with Zachary Sears, who directed InternalDesign at Digital B & E Corporation, New York,received the RFP from Cornell University for theantenna design, and studied the idea of suspending thefeed with his brother, Helias Doundoulakis, a civilengineer. George Doundoulakis identified the problemthat a tower or tripod would have presented around thecenter, the most important area of the reflector, anddevised a better approach by suspending the feed. Hepresented his proposal to Cornell for a doughnut trusssuspended by four cables from four towers above thereflector, having along its edge a rail track for theazimuthal positioning of the feed. A second truss, in the form of an arc, or arch, was tobe suspended below, which would rotate on the rails through 360 degrees. The arc alsohad rails on which the unit supporting the feed would move for the elevationalpositioning of the feed. A counter-weight would move symmetrically opposite to thefeed for stability, and the entire feed could be lowered and raised if a hurricane werepresent. Helias Doundoulakis designed the cable suspension system which was finallyadopted. Although the present configuration is substantially the same as the original

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drawings by George and Helias (though with three towers instead of the original four),

the U.S. Patent office granted Helias a patent[14] for the brothers' innovative idea.William J. Casey, later to be the director of the Central Intelligence Agency underPresident Ronald Reagan, was also an assignee on the patent.

Construction began in mid-1960, with the official opening on November 1, 1963.[15] Asthe primary dish is spherical, its focus is along a line rather than at a single point (aswould be the case for a parabolic reflector); therefore, complicated line feeds had to beused to carry out observations. Each line feed covered a narrow frequency band (2–5%of the center frequency of the band) and a limited number of line feeds could be used atany one time, limiting the flexibility of the telescope.

The telescope has been upgraded several times. Initially, when the maximum expectedoperating frequency was about 500 MHz, the surface consisted of half-inch galvanizedwire mesh laid directly on the support cables. In 1974 a high-precision surfaceconsisting of thousands of individually adjustable aluminum panels replaced the oldwire mesh, and the highest usable frequency was raised to about 5,000 MHz. AGregorian reflector system was installed in 1997, incorporating secondary and tertiaryreflectors to focus radio waves at a single point. This allowed the installation of a suiteof receivers, covering the whole 1–10 GHz range, that could be easily moved onto thefocal point, giving Arecibo more flexibility. At the same time, a ground screen wasinstalled around the perimeter to block the ground's thermal radiation from reaching thefeed antennas, and a more powerful 2,400 MHz transmitter was installed.

Research and discoveries

Many scientific discoveries have been made using the Arecibo telescope. On April 7,1964, shortly after it began operations, Gordon Pettengill's team used it to determinethat the rotation rate of Mercury was not 88 days, as previously thought, but only 59

days.[16] In 1968, the discovery of the periodicity of the Crab Pulsar (33 milliseconds)

by Lovelace and others provided the first solid evidence that neutron stars exist.[17] In

1974, Hulse and Taylor discovered the first binary pulsar PSR B1913+16,[18] anaccomplishment for which they later received the Nobel Prize in Physics. In 1982, thefirst millisecond pulsar, PSR B1937+21, was discovered by Donald C. Backer,

Shrinivas Kulkarni, Carl Heiles, Michael Davis, and Miller Goss.[19] This object spins642 times per second, and until the discovery of PSR J1748-2446ad in 2005, it was thefastest-spinning pulsar known.

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The Arecibo

message with

added color to

highlight the

separate parts.

The actual

binary

transmission

carried no color

information.

In August 1989, the observatory directly imaged an asteroid for the first time in history:

4769 Castalia.[20] The following year, Polish astronomer Aleksander Wolszczan madethe discovery of pulsar PSR B1257+12, which later led him to discover its three

orbiting planets and a possible comet.[21][22] These were the first extra-solar planetsdiscovered. In 1994, John Harmon used the Arecibo radio telescope to map the

distribution of ice in the poles of Mercury.[23]

In January 2008, detection of prebiotic molecules methanimine and hydrogen cyanidewere reported from Arecibo Observatory radio spectroscopy measurements of the

distant starburst galaxy Arp 220.[24]

The Arecibo message

Main article: Arecibo message

In 1974, the Arecibo message, an attempt to communicate withpotential extraterrestrial life, was transmitted from the radiotelescope toward the globular cluster M13, about 25,000 light-

years away.[25] The 1,679 bit pattern of 1s and 0s defined a 23 by73 pixel bitmap image that included numbers, stick figures,

chemical formulas, and a crude image of the telescope itself.[26]

Other uses

Terrestrial aeronomy experiments at Arecibo have included theCoqui 2 experiment, which were supported by NationalAeronautics and Space Administration (NASA).The telescope alsohas had military intelligence uses; among them, locating Sovietradar installations by detecting their signals bouncing off theMoon.

Arecibo is the source of data for the SETI@home and Astropulsedistributed computing projects put forward by the Space SciencesLaboratory at the University of California, Berkeley and was used

for the SETI Institute's Project Phoenix observations.[27] TheEinstein@Home distributed computing project has discovered

more than 20 pulsars in Arecibo data.[28]

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Funding issues

A report by the division of Astronomical Sciences of the National Science Foundation,made public on 2006-11-03, recommended substantially decreased astronomy fundingfor Arecibo Observatory, ramping down from $10.5 million in 2007 to $4.0 million in

2011.[29][30] If other sources of money cannot be obtained, the observatory wouldclose. The report also advised that 80 percent of the observation time be allocated tothe surveys already in progress, reducing the time available for other scientific work.NASA gradually eliminated its share of the planetary radar funding at Arecibo from

2001 thorough 2006.[31]

Academics and researchers responded by organizing to protect and advocate for theobservatory. They established the Arecibo Science Advocacy Partnership (ASAP),which was meant to advance the scientific excellence of Arecibo Observatory research

and to publicize its accomplishments in astronomy, aeronomy and planetary radar.[32]

ASAP's goals include mobilizing the existing broad base of support for Areciboscience within the fields it serves directly, the broad scientific community; provide aforum for the Arecibo research community and enhance communication within it;promote the potential of Arecibo for groundbreaking science; suggest the paths that willmaximize it into the foreseeable future; showcase the broad impact and far-reaching

implications of the science currently carried out with this unique instrument.[32]

Contributions by the government of Puerto Rico may be one way to help fill the fundinggap, but are controversial and uncertain. At town hall meetings about the potentialclosure, Puerto Rican Senate President Kenneth McClintock announced an initial localappropriation of $3.0 million during fiscal year 2008 to fund a major maintenanceproject to restore the three pillars that hold up the antenna platform to their original

condition, pending inclusion in the next bond issue.[33] The bond authorization, with the$3.0 million appropriation, was approved by the Senate of Puerto Rico on November

14, 2007, on the first day of a special session called by Aníbal Acevedo Vilá.[34] ThePuerto Rico House of Representatives repeated this action on June 30, 2008. The

Governor of Puerto Rico signed the measure into law in August 2008.[35] These fundswere made available in the second half of 2009.

José Enrique Serrano, a member of the U.S. House of Representatives AppropriationsCommittee, asked the National Science Foundation to keep Arecibo in operation in a

letter published on September 19, 2007.[36]

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Language similar to that in the letter of September 19 was included in the FY-2008omnibus spending bill. In October 2007, Puerto Rico's then-Resident Commissioner,Luis Fortuño, along with Dana Rohrabacher, filed legislation to assure the continued

operation of the observatory.[37] A similar bill was filed in the U.S. Senate in April

2008 by the junior Senator from New York, Hillary Clinton.[38]

Since the Arecibo observatory is owned by the Government of the United States, directdonations by private or corporate donors cannot be made. However, as non-profit(501(c)(3)) "public charities" under US law, Cornell University and subsequently SRI

International can accept contributions on behalf of the Arecibo Observatory.[39]

In September 2007, in an open letter to researchers, the NSF clarified the status of thebudget for NAIC, stating that the present plan could hit the targeted budgetary

revision.[40] No mention of private funding was made. However, it need be noted thatthe NSF is undertaking studies to mothball or demolish the observatory to return it to itsnatural setting in the event that its budget target is not reached.

In November 2007, The Planetary Society urged the U.S. Congress to prevent theArecibo Observatory from closing because of insufficient funding since its radar

contributes greatly to the accuracy of predictions of asteroid impacts on the Earth.[41]

The Planetary Society believes that continued operation of the observatory will reducethe cost of mitigation (that is, deflection of a near-Earth asteroid on collision to Earth),should that be necessary.

Also in November of that year The New York Times described the consequences of the

budget cuts at the site.[42] In July 2008, the British newspaper The Daily Telegraphreported that the funding crisis, due to federal budget cuts, was still very much

alive.[43]

The SETI@home program is using the telescope as a primary source for the research.The program is urging people to send a letter to their political representatives, in

support of full federal funding of the observatory.[44]

The NAIC received $3.1 million from the American Recovery and Reinvestment Act of2009, and this was used for basic maintenance and for a second, much smaller, antennato be used for very long baseline interferometry, new Klystron amplifiers for the

planetary radar system, and for student training.[45] This allotment was an increase of

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around 30 percent over the FY-2009 budget. However, the FY-2010 funding request byNSF was cut by $1.2 million (−12.5 percent) over the FY-2009 budget) in light of their

continued plans to reduce funding.[46]

The 2011 NSF budget was reduced by a further $1.6 million, −15 percent compared to

2010, with a further $1.0 million reduction projected by FY-2014.[47] Beginning in FY-2010, NASA began contributing $2.0 million per year for planetary science,particularly the study of near-Earth objects, at Arecibo. NASA implemented this

funding through its Near Earth Object Observations program.[48]

Also in 2010, the NSF issued a call for new proposals for the management of NAIC

beginning in FY-2012.[4] On May 12, 2011, the agency informed Cornell University thatit would no longer be the operator of the NAIC, and thus of the Arecibo Observatory, asof October 1, 2011. At that time, Cornell transferred its operations to SRI International,along with two other managing partners, Universities Space Research Association and

Universidad Metropolitana de Puerto Rico, with a number of other collaborators.[3][49]

Upon the award of the new cooperative agreement for NAIC management andoperation, NSF also decertified NAIC as a Federally Funded Research and

Development Center (FFRDC),[47] with the stated goal of providing the NAIC withgreater freedom to establish broader scientific partnerships and pursue funding

opportunities for activities beyond the scope of those supported by the NSF.[50]

In popular culture

The Arecibo Observatory was featured on Cosmos: A Personal Voyage in Part 12"Encyclopaedia Galactica."The Arecibo Observatory is featured at the end of James Burke's TV seriesConnections in Part 3 "Distant Voices."Arecibo Observatory was used as a filming location in the climax of the JamesBond movie GoldenEye and as a level in the accompanying Nintendo 64videogame GoldenEye 007.Season 2 episode 22 of the cartoon Jackie Chan Adventures featured a spoof of theJames Bond movie GoldenEye, and similarly ended the plot at the AreciboObservatoryThe film Contact features Arecibo, where the main character uses the facility aspart of a SETI project.Fox Mulder was sent to the Arecibo Observatory in The X-Files episode "Little

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Green Men".Songwriter and author Jimmy Buffett mentions the "giant telescope" in his bookWhere Is Joe Merchant?, and in the lyrics to the song "Desdemona's Building ARocket Ship".The musicians Boxcutter, Lustmord, and Little Boots have all released albumsnamed Arecibo.The observatory is featured in the film Species, the James Gunn novel TheListeners (1972), the Robert J. Sawyer novel Rollback, and the Mary DoriaRussell novel The Sparrow.Arecibo Observatory also featured in the action movie The Losers (2010).In the video game Just Cause 2 there is a large radio observatory called PANMILSAT that is very similar in appearance to Arecibo Observatory.Internet radio station Arecibo Radio is named after the observatory.[1](http://areciboradio.com)The Arecibo Observatory was featured in an episode Covert Affairs called"Loving the Alien" as a stand-in for the Lourdes SIGINT Station.

Arecibo Observatory Directors

1963–1965, Dr. William E. Gordon (Ph.D., Cornell University)1965–1966, John W. Findlay (Ph.D., University of Cambridge)1966–1968, Dr. Frank Drake (Ph.D., Harvard University)1968–1970, Dr. Gordon Pettengill (Ph.D., UC Berkeley)1971–1973, Dr. Tor Hagfors (Ph.D., University of Oslo)1973–1981, Dr. Harold D. Craft Jr. (Ph.D., Cornell University)1981–1987, Dr. Donald B. Campbell (Ph.D., Cornell University)1988–1989 (interim) Dr. Riccardo Giovanelli (Ph.D., University of Bologna)1988–1992, Dr. Michael M. Davis (Ph.D., Leiden University)1992–2003, Dr. Daniel R. Altschuler (Ph.D., Brandeis University)2003–2006, Dr. Sixto A. González (Ph.D., Utah State University)2006–2007 (interim) Dr. Timothy L. Hankins (Ph.D., University of California atSan Diego)2007–2008, Dr. Robert B. Kerr (Ph.D., University of Michigan)2008–2011, (interim 2008) Dr. Michael C. Nolan (Ph.D., University of Arizona)2011–present, Dr. Robert B. Kerr (Ph.D., University of Michigan)

See also

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Air Force Research LaboratoryList of radio telescopesSixto A. González, former director of the Arecibo Observatory (2003–2006)William E. Gordon, founder and first director of the observatory (AIO 1963–1965)Tor Hagfors, former director of the Arecibo Observatory (1971–1973) and also ofNAIC (October 1982 to September 1992).

Helias Doundoulakis[51]

UPRM Planetarium

References

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14. ^ US patent 3273156 (http://worldwide.espacenet.com/textdoc?DB=EPODOC&IDX=US3273156), Helias Doundoulakis, "Radio Telescope having ascanning feed supported by a cable suspension over a stationary reflector", issued 1966-09-13

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21. ^ Wolszczan, A. (1994). "Confirmation of Earth Mass Planests Orbiting the MilliesecondPulsar PSR: B1257+12". Science. p. 538.

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24. ^ Staff (15 January 2008). "Life's Ingredients Detected In Far Off Galaxy"(http://www.sciencedaily.com/releases/2008/01/080114110715.htm). ScienceDaily(ScienceDaily LLC). Archived(http://web.archive.org/web/20080421095946/http://www.sciencedaily.com/releases/2008/01/080114110715.htm) from the original on April 21, 2008. Retrieved 2008-03-29. "[Article] Adapted from materials provided by Cornell University."

25. ^ Larry Klaes (30 November 2005). "Making Contact"(http://www.zwire.com/site/news.cfm?newsid=15663534&BRD=1395&PAG=461&dept_id=216620&rfi=6). Ithaca Times.Retrieved 2008-09-02.

26. ^ Geaorge Cassiday. "The Arecibo Message"(http://www.physics.utah.edu/~cassiday/p1080/lec06.html). The University of Utah:Department of Physics. Archived(http://web.archive.org/web/20070717133904/http://www.physics.utah.edu/~cassiday/p1080/lec06.html) from the original on July 17, 2007. Retrieved 2007-07-27.

27. ^ Peter Backus (14 April 2003). "Project Phoenix: SETI Prepares to Observe at Arecibo"(https://www.space.com/searchforlife/seti_arecibo_prep_030414.html). Space.com.Retrieved 2008-09-02.

28. ^ "Einstein@Home new discoveries and detections of known pulsars in the BRP4 search"(http://einstein.phys.uwm.edu/radiopulsar/html/BRP4_discoveries/). Einstein@Home.August 27, 2012. Retrieved August 28, 2012.

29. ^ Roger Blandford; Senior Review Committee, Division of Astronomical Sciences,National Science Foundation (22 October 2006). From the Ground Up: Balancing theNSF Astronomy Program(http://www.nsf.gov/mps/ast/seniorreview/sr_report_mpsac_updated_12-1-06.pdf) (PDF).National Science Foundation. Archived(http://web.archive.org/web/20080626170308/http://www.nsf.gov/mps/ast/seniorreview/sr_report_mpsac_updated_12-1-06.pdf) from the original on June 26, 2008. Retrieved2008-07-08.

30. ^ Rick Weiss (9 September 2007). "Radio Telescope And Its Budget Hang in the Balance"(http://www.washingtonpost.com/wp-dyn/content/article/2007/09/08/AR2007090801654.html?hpid=moreheadlines). TheWashington Post (Arecibo, Puerto Rico: The Washington Post Company). p. A01.Retrieved 2008-07-08. "The cash crunch stems from a "senior review" completed lastNovember at NSF. Its $200 million astronomy division – increasingly committed toambitious, new projects but long hobbled by flat Congressional budgets – was facing adeficit of at least $30 million by 2010."

31. ^ Robert Roy Britt (20 December 2001). "NASA Trims Arecibo Budget, Says OtherOrganizations Should Support Asteroid Watch"(http://www.space.com/scienceastronomy/astronomy/arecibo_cuts_011220.html).

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(http://www.space.com/scienceastronomy/astronomy/arecibo_cuts_011220.html).Space.com. Imaginova. Retrieved 2008-07-08.

32. ^ a b "Areciboscience.org" (http://areciboscience.org/index.html). Areciboscience.org.Retrieved 2012-05-11.

33. ^ Liz Arelis Cruz Maisonave. "Buscan frenar cierre de Radiotelescopio en Arecibo"(http://www.vocero.com/noticias.asp/s=Locales&n=82569). El Vocero (in Spanish).Retrieved 2008-09-04.

34. ^ "Senado aprueba emisión de bonos de $450 millones"(http://www.primerahora.com/XStatic/primerahora/template/nota.aspx?n=128502).Primera Hora (in Spanish). 14 November 2007. Retrieved 2008-09-04.

35. ^ Gerardo E, Alvarado León (10 August 2008). "Gobernador firma emisión de bonos". ElNuevo Día.

36. ^ José E. Serrano (19 September 2007). "Serrano concerned about potential Areciboclosure"(http://web.archive.org/web/20080730201844/http://serrano.house.gov/PressRelease.aspx?NewsID=1473). serrano.house.gov. Archived from the original(http://serrano.house.gov/PressRelease.aspx?NewsID=1473) on 30 July 2008. Retrieved2008-09-04.

37. ^ "Congress gets bill to save Arecibo Observatory"(http://www.news.cornell.edu/stories/Oct07/Arecibo.bill.lg.html). Cornell University. 3October 2007. Archived(http://web.archive.org/web/20080821133911/http://www.news.cornell.edu/stories/Oct07/Arecibo.bill.lg.html) from the original on August 21, 2008. Retrieved 2008-09-04.

38. ^ Jeannette Rivera-lyles (25 April 2008). "Clinton turns attention to observatory in PuertoRico" (http://www.orlandosentinel.com/news/nationworld/orl-arecibo2508apr25,0,5117790.story). Orlando Sentinel. Archived(http://web.archive.org/web/20080930045739/http://www.orlandosentinel.com/news/nationworld/orl-arecibo2508apr25,0,5117790.story) from the original on September 30, 2008.Retrieved 2008-09-04.

39. ^ "Arecibo-observatory.org" (http://arecibo-observatory.org). Cornell and NAIC. 22 June2008. Archived (http://web.archive.org/web/20080707072836/http://www.arecibo-observatory.org/) from the original on July 07 2008. Retrieved 2008-07-08. "Our missionis to establish a new funding model to supplement NSF support and maintain operations ofthe observatory now and into the future."

40. ^ "Dear Colleague Letter: Providing Progress Update on Senior ReviewRecommendations" (http://www.nsf.gov/publications/pub_summ.jsp?ods_key=nsf07052)(Press release). The National Science Foundation. 20 September 2007. Archived(http://web.archive.org/web/20080628044214/http://www.nsf.gov/publications/pub_summ.jsp?ods_key=nsf07052) from the original on June 28, 2008. Retrieved 2008-07-09.

41. ^ Arecibo participated in 90 of the 111 asteroid radar observations in 2005–2007. SeeJPL's list of all asteroid radar observations.(http://echo.jpl.nasa.gov/asteroids/PDS.asteroid.radar.history.html)

42. ^ Chang, K., "A Hazy Future for a 'Jewel' of Space Instruments."(http://www.nytimes.com/2007/11/20/science/space/20scop.html?scp=2), New YorkTimes, November 20, 2007

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Times, November 20, 200743. ^ Jacqui Goddard, "Threat to world's most powerful radio telescope means we may not

hear ET" (http://www.telegraph.co.uk/news/worldnews/northamerica/usa/2291068/Threat-to-world%27s-most-powerful-radio-telescope-means-we-may-not-hear-ET.html), DailyTelegraph, July 12, 2008

44. ^ "Save Arecibo: Write to Congress" (http://setiathome.berkeley.edu/arecibo_letter.php).Retrieved July 19, 2008

45. ^ "12-m Phase Reference Antenna"(http://www.naic.edu/science/new12m_antenna_arecibo.html). Naic.edu. 28 June 2010.Retrieved 2012-05-11.

46. ^ "FY2010 Budget Request to Congress"(http://www.nsf.gov/about/budget/fy2010/toc.jsp). Retrieved May 26, 2009

47. ^ a b "Major multi-user research facilities"(http://www.nsf.gov/about/budget/fy2011/pdf/22-Facilities_fy2011.pdf) p. 35–38.Retrieved 2010 Feb. 10

48. ^ "NASA Support to Planetary Radar"(http://science.nasa.gov/media/medialibrary/2010/04/27/NASAsupport_to_Planetary_Radar.pdf) retrieved 2011 July 7

49. ^ "SRI International to manage Arecibo Observatory"(http://www.news.cornell.edu/stories/June11/AreciboStmt.html). Cornell Chronicle. 3June 2011. Retrieved 2012-01-11.

50. ^ "Management and Operation of the NAIC"(http://www.nsf.gov/funding/pgm_summ.jsp?pims_id=5652) retrieved 2013 Apr 6

51. ^ "3,273,156 (1966-09-13) Helias Doundoulakis, Radio Telescope having a scanning feedsupported by a cable suspension over a stationary reflector"(http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=3273156.PN.&OS=PN/3273156&RS=PN/3273156). U.S.Patent Office.

Further reading

Friedlander, Blaine P. Jr. (1997-11-14). "Research rockets, including anexperiment from Cornell, are scheduled for launch into the ionosphere next yearfrom Puerto Rico" (http://www.news.cornell.edu/releases/Nov97/Coqui-II.bpf.html). Cornell University.Ruiz, Carmelo (1998-03-03). "Activists protest US Navy radar project"(http://www.globenet.free-online.co.uk/actions/prico2.htm). Global NetworkAgainst Weapons and Nuclear Power in Space.Amir Alexander (July 3, 2008). "Budget Cuts Threaten Arecibo Observatory"(http://www.planetary.org/programs/projects/advocacy_and_education/space_adv

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ocacy/20080703.html). The Planetary Society.Blaine Friedlander (June 10, 2008). "Arecibo joins global network to create6,000-mile (9,700 km) telescope" (http://www.eurekalert.org/pub_releases/2008-06/cuc-ajg061008.php). EurekAlert.Lauren Gold (June 5, 2008). "Clintons (minus Hillary) visit Arecibo; formerpresident urges more federal funding for basic sciences"(http://www.news.cornell.edu/stories/June08/arecibo.clintons.html). Cornelluniversity.Henry Fountain (December 25, 2007). "Arecibo Radio Telescope Is Back inBusiness After 6-Month Spruce-Up"(http://www.nytimes.com/2007/12/25/science/25obtele.html). New York Times.Entry into the National Register of Historic Places(http://www.nps.gov/history/nr/feature/weekly_features/IonosphereCenter.pdf)

External links

Arecibo Observatory (http://www.naic.edu)Arecibo Science Advocacy Partnership (http://areciboscience.org)Angel Ramos Foundation Visitor Center(http://www.naic.edu/outreach/describe_fset.htm)SETI@home (http://setiathome.ssl.berkeley.edu)IEEE History Center – IEEE Milestones: NAIC/Arecibo Radiotelescope(http://www.ieeeghn.org/wiki/index.php/Milestones:NAIC/Arecibo_Radiotelescope,_1963)Lofar (http://www.lofar.nl)The Arecibo Observatory Contributions Site (http://arecibo-observatory.org)Letter to save Arecibo Observatory(http://setiathome.berkeley.edu/arecibo_letter.php)

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