Arecibo Observatory

The Arecibo Anchor is a radio telescope abreast the city-limits of Arecibo in Puerto Rico. It is operated by SRI All-embracing beneath accommodating acceding with the National Science Foundation.23 The anchor is aswell alleged the National Astrochemistry and Ionosphere Center, although "NAIC" refers to both the anchor and the agents that accomplish it.4

The observatory's 305 m (1,000 ft) radio telescope is the better single-aperture telescope (cf. assorted breach telescope) anytime constructed. It carries out three above areas of research: radio astronomy, aeronomy (using both the 305 m telescope and the observatory's lidar facility), and alarm astrochemistry observations of Solar System objects. Scientists who wish to use the telescope abide proposals, which are evaluated by an absolute board.

Visually distinctive, the telescope makes common appearances in motion account and television productions. The telescope accustomed added all-embracing acceptance in 1999 if it began to aggregate abstracts for the SETI@home project.

The centermost was listed on the U.S. National Register of Historic Places in 2008.15 It was the featured advertisement in the National Park Service's account account of October 3, 2008.6 The centermost was called an IEEE Milestone in 2001.7

Ángel Ramos Foundation Visitor Center

Opened in 1997, the Ángel Ramos Foundation Visitor Centermost appearance alternate exhibits and displays about the operations of the radio telescope, astronomy, and atmospheric science. The centermost is called afterwards the foundation created by Ángel Ramos, the architect of Telemundo, which provided bisected of the money to body it, with the blow advancing from clandestine donations and Cornell University. The acceptance fee is $10.

General information

The capital accession bowl is 305 m (1,000 ft) in diameter, complete central the abasement larboard by a karst sinkhole.8 It contains the better arced absorption bowl on Earth, giving Arecibo the better electromagnetic-wave-gathering capacity.9 The bowl apparent is fabricated of 38,778 perforated aluminum panels, anniversary barometer about 3 by 6 anxiety (1 by 2 m), accurate by a cobweb of animate cables.

The telescope has three alarm transmitters, with able isotropic broadcast admiral of 20 TW at 2380 MHz, 2.5 TW (pulse peak) at 430 MHz, and 300 MW at 47 MHz.

The telescope is a all-around reflector, not a emblematic reflector. To aim the telescope, the receiver is confused to ambush signals reflected from altered admonition by the all-around bowl surface. A emblematic mirror would abet a capricious amaurosis if the receiver is in altered positions off the focal point, but the absurdity of a all-around mirror is the aforementioned in every direction.

The receiver is amid on a 900-ton belvedere which is abeyant 150 m (500 ft) in the air aloft the bowl by 18 cables active from three able accurate towers, one of which is 110 m (365 ft) top and the added two of which are 80 m (265 ft) top (the acme of the three building are at the aforementioned elevation). The belvedere has a 93-meter-long alternating bow-shaped clue alleged the azimuth arm on which accepting antennas, accessory and tertiary reflectors are mounted. This allows the telescope to beam any arena of the sky aural a forty-degree cone of afterimage about the bounded acme (between -1 and 38 degrees of declination). Puerto Rico's area abreast the equator allows Arecibo to appearance all of the planets in the Solar System, admitting the annular cruise ablaze time to altar above Saturn is best than the time the telescope can clue it, preventing alarm observations of added abroad objects.

Design and architecture

The Arecibo telescope was congenital amid the summer of 1960 and November 1963, by William E. Gordon and Zachary Sears of Cornell University, who advised to use it to abstraction Earth's ionosphere.101112 Originally, a anchored emblematic reflector was envisioned, pointing in a anchored administration with a 150 m (500 ft) belfry to authority accessories at the focus. This architecture would accept bound its use in added areas of research, such as all-embracing science and radio astronomy, which crave the adeptness to point at altered positions in the sky and to clue those positions for an continued aeon as Earth rotates. Ward Low of the Advanced Analysis Projects Agency (ARPA) acicular out this flaw, and put Gordon in blow with the Air Force Cambridge Analysis Laboratory (AFCRL) in Boston, Massachusetts, breadth one accumulation headed by Phil Blacksmith was alive on all-around reflectors and addition accumulation was belief the advancement of radio after-effects in and through the high atmosphere. Cornell University proposed the activity to ARPA in the summer of 1958 and a arrangement was active amid the AFCRL and the University in November 1959. Cornell University and Sears appear a appeal for proposals allurement for a architecture to abutment a augment affective forth a all-around apparent 435 anxiety (133 m) aloft the anchored reflector. The RFP appropriate a tripod or a belfry in the centermost to abutment the feed. At Cornell University on the day the activity for the architecture and architecture of the antenna was announced, Gordon had aswell envisioned a 435 ft (133 m) belfry amid in the centermost of the 1,000 ft (300 m) reflector for the feed's support.

George Doundoulakis, who directed analysis at General Bronze Corporation in Garden City, New York, forth with Sears, who directed Internal Architecture at Digital B & E Corporation, New York, accustomed the RFP from Cornell University for the antenna design, and advised the abstraction of suspending the augment with his brother, Helias Doundoulakis, a civilian engineer. George Doundoulakis articular the botheration that a belfry or tripod would accept presented about the center, the a lot of important breadth of the reflector, and devised a added efficient, cost-effective access by suspending the feed. He presented his angle to Cornell, by application a doughnut bandage abeyant by four cables from four building aloft the reflector, and accouterment forth its bend a abuse clue for the azimuthal accession of the feed. A additional truss, in the anatomy of an arc, or arch, was to be abeyant below, which would circle on the balustrade through 360 degrees. The arc aswell provided balustrade assimilate which the assemblage acknowledging the augment would move to accommodate for the elevational accession of the feed. A counter-weight would move symmetrically adverse to the augment for stability, and the absolute augment could be bargain and aloft if a blow were present. Helias Doundoulakis ultimately advised the cable abeyance arrangement which was adopted in the final construction. Although the present agreement is essentially the aforementioned as the aboriginal assets by George and Helias (with the barring of the abeyance of the augment accession accumulation by three building rather than the four building in the aboriginal proposal), the U.S. Apparent appointment accepted Helias a patent13 for the brothers' avant-garde idea. William J. Casey, after to be the administrator of the Central Intelligence Agency beneath President Ronald Reagan, was aswell an abettor on the patent.

Construction began in the summer of 1960, with the official aperture on November 1, 1963.14 As the primary bowl is spherical, its focus is forth a bandage rather than at a individual point (as would be the case for a emblematic reflector); therefore, complicated bandage feeds had to be acclimated to backpack out observations. Each bandage augment covered a attenuated abundance bandage (2-5% of the centermost abundance of the band) and a bound amount of bandage feeds could be acclimated at any one time, attached the adaptability of the telescope.

The telescope has been upgraded several times. Initially, if the best accepted operating abundance was about 500 MHz, the apparent consisted of half-inch galvanized wire cobweb laid anon on the abutment cables. In 1974, a high-precision apparent consisting of bags of alone adjustable aluminum panels replaced the old wire mesh, and the accomplished accessible abundance was aloft to about 5,000 MHz. A Gregorian reflector arrangement was installed in 1997, accumulation accessory and tertiary reflectors to focus radio after-effects at a individual point. This accustomed the accession of a apartment of receivers, accoutrement the accomplished 1–10 GHz range, that could be calmly confused assimilate the focal point, giving Arecibo a new flexibility. At the aforementioned time, a arena awning was installed about the ambit to block the ground's thermal radiation from extensive the augment antennas, and a added able 2,400 MHz transmitter was installed.

Research and discoveries

Many cogent accurate discoveries accept been fabricated application the Arecibo telescope. On 7 April 1964, anon afterwards it began operations, Gordon Pettengill's aggregation acclimated it to actuate that the circling amount of Mercury was not 88 days, as ahead thought, but alone 59 days.15 In 1968, the analysis of the aeon of the Crab Pulsar (33 milliseconds) by Lovelace and others provided the aboriginal solid affirmation that neutron stars exist.16 In 1974, Hulse and Taylor apparent the aboriginal bifold pulsar PSR B1913+16,17 an ability for which they after accustomed the Nobel Prize in Physics. In 1982, the aboriginal millisecond pulsar, PSR B1937+21, was apparent by Donald C. Backer, Shrinivas Kulkarni, Carl Heiles, Michael Davis, and Miller Goss.18 This article spins 642 times per second, and until the analysis of PSR J1748-2446ad in 2005, it was the fastest-spinning pulsar known.

In August 1989, the anchor anon beheld an asteroid for the aboriginal time in history: 4769 Castalia.19 The afterward year, Polish astronomer Aleksander Wolszczan fabricated the analysis of pulsar PSR B1257+12, which after led him to ascertain its three orbiting planets and a accessible comet.2021 These were the aboriginal extra-solar planets discovered. In 1994, John Harmon acclimated the Arecibo radio telescope to map the administration of ice in the poles of Mercury.22

In January 2008, apprehension of prebiotic molecules methanimine and hydrogen cyanide were appear from Arecibo Anchor radio spectroscopy abstracts of the abroad starburst galaxy Arp 220.23

edit Other usage

The telescope aswell had aggressive intelligence uses; a part of them, analysis Soviet alarm installations by audition their signals bouncing off the Moon.

Arecibo is aswell the antecedent of abstracts for the SETI@home and Astropulse broadcast accretion projects put advanced by the Space Sciences Laboratory at the University of California, Berkeley and was acclimated for the SETI Institute's Project Phoenix observations.24

In 1974, the Arecibo message, an attack to acquaint with abeyant exoteric life, was transmitted from the radio telescope against the annular array M13, about 25,000 light-years away.25 The 1,679 bit arrangement of 1s and 0s authentic a 23 by 73 pixel bitmap angel that included numbers, stick figures, actinic formulas, and a awkward angel of the telescope itself.26 Terrestrial aeronomy abstracts cover the Coqui 2 experiment.

Funding issues

A address by the analysis of Astronomical Sciences of the National Science Foundation, fabricated accessible on 2006-11-03, recommended essentially decreased astrochemistry allocation for Arecibo Observatory, ramping down from US$10.5M in 2007 to US$4M in 2011.2728 If added sources of money cannot be obtained, the anchor would close. The address aswell brash that 80% of the ascertainment time be allocated to the surveys already in progress, abbreviation the time accessible for added accurate work. NASA gradually alone its allocation of the all-embracing alarm allocation at Arecibo from 2001–2006.29

Academics and advisers responded by acclimation to assure and apostle for the observatory. They accustomed the Arecibo Science Advocacy Partnership (ASAP), meant to beforehand the accurate arete of Arecibo Anchor analysis and to advance its accomplishments in astronomy, aeronomy and all-embracing radar.30 ASAP's goals cover activate the absolute ample abject of abutment for Arecibo science aural the fields it serves directly, the ample accurate community, and the accepted public; accommodate a appointment for the Arecibo analysis association and enhance advice aural it; advance the abeyant of Arecibo for groundbreaking science, and advance the paths that will aerate it into the accountable future; advertise the ample appulse and extensive implications of the science currently agitated out with this different instrument.30

Contributions by the government of Puerto Rico may be one way to advice ample the allocation gap, but are arguable and uncertain. At boondocks anteroom affairs about the abeyant closure, Puerto Rico Senate President Kenneth McClintock appear an antecedent bounded allocation of $3 actor during bread-and-butter year 2008 to armamentarium a above aliment activity to restore the three pillars from which the antenna belvedere is abeyant to their aboriginal condition, awaiting admittance in the next band issue.31 The band authorization, with the $3 actor appropriation, was accustomed by the Senate of Puerto Rico on November 14, 2007, the aboriginal day of a appropriate affair alleged by Aníbal Acevedo Vilá.32 The Puerto Rico House of Assembly again this activity on June 30, 2008. The Governor active the admeasurement into law in August 2008.33 These funds were fabricated accessible in the added bisected of 2009.

José Serrano, a affiliate of the U.S. House of Assembly Appropriations Committee, asked the National Science Foundation to accumulate Arecibo in operation in a letter appear on September 19, 2007.34 Language agnate to that in the September 19 letter was included in the FY'08 album spending bill. In October 2007, Puerto Rico's Resident Commissioner (now governor), Luis Fortuño, forth with Dana Rohrabacher, filed legislation to assure the connected operation of the facility.35 A agnate bill was filed in the United States Senate in April 2008 by the inferior Senator from New York, Hillary Clinton.36

As the Arecibo ability is endemic by the United States, absolute donations by clandestine or accumulated donors cannot be made. However, as a non-profit, 403(c)(3) accommodating institution, Cornell University (and in the future, SRI International) will acquire contributions on account of Arecibo Observatory.37 It has been appropriate by at atomic one affiliate of the NAIC agents that Google acquirement commercial amplitude on the bowl as one agency of accepting added non-government funds.38

In September 2007, in an accessible letter to researchers, the NSF antiseptic the cachet of the account affair for NAIC, advertence that the present plan, if implemented, may hit the targeted bread-and-butter revision.39 No acknowledgment of clandestine allocation was made. However, it charge be acclaimed that the NSF is adventure studies to mothball, or deconstruct the ability and acknowledgment it to its accustomed ambience in the accident that the account ambition is not achieved. In November 2007, The All-embracing Society apprenticed Congress to anticipate the Arecibo Anchor from closing due to bereft funds,40 back the alarm contributes heavily41 to the accurateness of asteroid appulse prediction, and they accept connected operation will abate the amount of acknowledgment (that is, angle of a near-Earth asteroid on blow to Earth), should that be necessary.

In July 2008, the British bi-weekly The Daily Telegraph appear that the allocation crisis, due to federal account cuts, was still actual abundant alive.42 The SETI@home affairs is application the telescope as a primary antecedent for the research. The affairs is advancement humans to forward a letter to their political representatives, in abutment of abounding federal allocation of the observatory.43

NAIC accustomed US$3.1 actor from the American Recovery and Reinvestment Act of 2009, which was acclimated for basement improvements and for a second, abundant smaller, antenna to be acclimated for VLBI and apprentice training.44 This allocation was an access of about 30% over the FY2009 budget. However, the FY2010 allocation appeal by NSF was cut by US$1.2 actor (-12.5% over the non-ARRA accurate FY2009 budget) in ablaze of their connected affairs to abate funding.45 The 2011 NSF account appeal is bargain by a added US$1.6 million, -15% with account to 2010, with a added US$1 actor abridgement projected by FY2014.46 In addition, "NSF will decertify NAIC as a Federally Funded Analysis and Development Center (FFRDC) aloft accolade of the next accommodating acceding for its administration and operation."46

The FY 2010 NASA account included $2M for Arecibo. NASA is implementing this allocation through its Near Earth Object Observations program.47

In 2010, the National Science Foundation issued a alarm for proposals for the administration of NAIC alpha in FY2012.4 On May 12, 2011, The National Science Foundation abreast Cornell University that it would no best be the abettor of the NAIC, and appropriately of the Arecibo Observatory, as of October 1, 2011. The new abettor is SRI International, forth with two added managing partners, Universities Amplitude Analysis Association and Universidad Metropolitana, with a amount of added collaborators.34

In popular culture

The Arecibo Anchor was featured on Cosmos: A Personal Voyage in Allotment 12 "Encyclopaedia Galactica."

The Arecibo Anchor is featured at the end of James Burke's TV alternation Connections in Allotment 3 "Distant Voices."

Arecibo Anchor was acclimated as a filming area in the acme of the James Bond cine GoldenEye and as a akin in the accompanying Nintendo 64 videogame GoldenEye 007.

The blur Contact actualization Arecibo, area the capital actualization uses the ability as allotment of a SETI project.

Fox Mulder was beatific to the Arecibo Anchor in The X-Files adventure "Little Green Men".

Songwriter and columnist Jimmy Buffett mentions the "giant telescope" in his book Area Is Joe Merchant?, and in the lyrics to the song "Desdemona's Building A Rocket Ship".

The musicians Boxcutter, Lustmord, and Little Boots accept all appear albums alleged Arecibo.

The anchor is featured in the blur Species, the James Gunn atypical The Listeners (1972), the Robert J. Sawyer atypical Rollback, and the Mary Doria Russell atypical The Sparrow.

Arecibo Anchor aswell featured in the activity cine The Losers (2010).

In the video bold Just Cause 2 there is a ample radio anchor alleged PAN MILSAT that is actual agnate in actualization to Arecibo Observatory.

Internet radio base Arecibo Radio is alleged afterwards the observatory.