World’s largest telescope puerto rico: Hopes Fade for Resurrecting Puerto Rico’s Famous Arecibo Telescope

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March 6, 2023
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Hopes Fade for Resurrecting Puerto Rico’s Famous Arecibo Telescope

Nearly two years ago one of the most iconic telescopes in the world came crashing down on itself. The Arecibo telescope—located in Arecibo, Puerto Rico—was the world’s largest single-dish telescope for most of its more than half-century of existence. A series of cable failures caused the telescope’s 817-metric-ton receiver platform to collapse onto the dish below on December 1, 2020, putting the telescope out of commission.

Last week, the National Science Foundation (NSF)—which owns and finances the Arecibo Observatory—announced that it would not be funding the telescope’s reconstruction. Likewise, the NSF’s funding plan will not provide “operational support for current scientific infrastructure” at the Arecibo Observatory, such as its 12-meter radio telescope or its Lidar facility. Instead the NSF is soliciting proposals from universities or other groups that could establish a new center for STEM (science, technology, engineering and mathematics) education and outreach at Arecibo with an annual budget of $1 million per year for five years.

Many astronomers were disappointed—but not surprised—by the announcement. “We were aware that the NSF was going to make a tough decision…, but we were expecting a little bit better than that,” says Abel Méndez, a planetary astrobiologist at the University of Puerto Rico at Arecibo. Méndez didn’t expect that the Arecibo telescope would be rebuilt but says he had hoped that the observatory would continue to receive funding for its other on-site instruments.

Still, there’s no doubt that the Arecibo telescope was the flagship instrument of the Arecibo Observatory and what allowed the site to stand out on the global stage. The telescope was built into a natural sinkhole in the northwest of Puerto Rico, which offered the perfect geography to accommodate its curved, 305-meter-diameter reflector dish. The Arecibo telescope was completed in 1963, and for decades, it was the most sensitive radio telescope in the world.

Thanks to its ability to detect faint radio signals, the Arecibo telescope was able to advance many areas of astronomy. One such area was the search for extraterrestrial intelligence, or SETI.

“I think it’s probably fair to say that, historically speaking, the Arecibo telescope has been the most important radio telescope for SETI, period,” says Andrew Siemion, director of the Berkeley SETI Research Center. Siemion explains that much of the Arecibo telescope’s early research centered on studying Earth’s atmosphere and ionosphere, but late astronomer Frank Drake pushed for the expansion of its radio capabilities—in part to scan the skies for potential alien signals. Besides trying to detect messages, the Arecibo telescope famously sent one of its own in 1974. That “Arecibo message,” designed by Drake, could be decoded into a simple pixel-art image providing basic information about life on Earth.

In addition to its contributions to SETI, the Arecibo telescope was used to identify the first confirmed exoplanets. Observing the millisecond radio pulsar PSR B1257+12, the giant dish revealed slight deviations in the rapidly-rotating star’s radio pulses, betraying the presence of at least two planets, both just a few times larger than Earth. These planets were announced by astronomers Aleksander Wolszczan and Dale Frail in 1992.

The Arecibo telescope’s radio observations continued until its collapse in 2020. “It is extraordinary—maybe unprecedented—for a radio telescope to stay as productive as it has for so long,” says Frail, who works at the National Radio Astronomy Observatory.

Yet in its later years, the Arecibo telescope began to fall out of favor among many radio astronomers. “There’s been a move towards multielement telescopes—constructing large telescopes with lots of small pieces,” Siemion explains. Rather than go to the trouble of building radio telescopes with single, massive dishes, it has become easier and more effective to set up arrays of smaller telescopes working in conjunction, he says.

That’s not to say that huge single-dish radio telescopes have been abandoned altogether. In 2016 China unveiled its Five-Hundred-Meter Aperture Spherical Telescope (FAST), which dethroned Arecibo as the world’s largest single-dish telescope. Although multidish arrays are more complicated in some respects, they are also correspondingly more functionally flexible and have thus become the preference for most modern radio astronomers. Today such arrays can be found around the world.

“I am sorry to see the Arecibo telescope go the way of so many other radio telescopes in the past,” Frail says, “as they all have had to make way for newer, more powerful telescopes.”

Yet the Arecibo telescope wasn’t just a radio telescope. It was also a radar telescope, capable of transmitting powerful beams out to objects in the solar system. Once reflected back to the dish, those beams allowed researchers to precisely measure the sizes, spins, surfaces and several other properties of the objects. Such radar probes have proved especially vital for studying potentially Earth-threatening asteroids.

Radar data from the Arecibo telescope “has been used to help us understand the range of physical properties that near-Earth asteroids could have and the range of situations we might need to be prepared for,” says Andy Rivkin, a planetary astronomer at Johns Hopkins University. Rivkin notes that the Arecibo telescope helped scientists plan out NASA’s Double Asteroid Redirection Test (DART) mission—the agency’s attempt to knock an asteroid off its course, which Rivkin helped lead. Prior to the mission’s launch, the Arecibo telescope collected precise radar data on the shape and size of the asteroid Didymos and on the size and orbit of its moonlet Dimorphos, Rivkin says, which helped NASA to successfully impact Dimorphos on September 26.

“Arecibo was absolutely still producing important data for asteroid science at the time of its collapse, and there is no replacement for its specific capabilities for high-resolution radar studies,” Rivkin says.

After the Arecibo telescope’s collapse, the NSF was faced with a few options: rebuild the telescope as it was, rebuild it in some upgraded fashion or don’t rebuild it at all. The first two options had projected price tags of several hundred million dollars. (It cost $30 million to $50 million just to clean up the collapse, according to an NSF estimate. ) Preferring to spend its budget on other facilities many astronomers deemed more desirable and viable, the NSF opted not to rebuild the telescope.

Much of the radio astronomy capabilities “that were lost as a result of the [telescope’s] collapse can be recovered through additional investments in existing facilities and through international partnerships,” wrote a spokesperson for the NSF in an e-mail to Scientific American. As for radar, “NSF engaged NASA and other federal agency partners to explore next-generation ground-based radar needs.”

Regarding proposals for a new center for STEM education and outreach at Arecibo that the agency will field, “NSF recognizes the scientific, educational, historic, cultural and economic significance of the Arecibo Observatory site to Puerto Rico and the global scientific community and is focusing on leveraging the incredible STEM educational potential of the facility,” the NSF spokesperson wrote. It is not yet clear how this educational center would incorporate the observatory’s existing visitor center, which already runs educational outreach programs.

Méndez is glad that the NSF has decided to invest in local educational outreach, but he emphasizes that having the capacity for cutting-edge astronomy research on the island is likely even more critical for creating more Puerto Rican scientists. When it was still operational, visits to the Arecibo telescope inspired many local students to pursue a career in STEM—and astronomy specifically—Méndez says. When Méndez himself was younger, he already knew he wanted to study astronomy, but visiting the Arecibo telescope “gave [him] confidence,” he says. “Having this huge, important astronomical place nearby made me feel included” in the astronomical community, he explains.

Méndez hopes that the winner of the NSF’s $5-million grant to establish an education center will independently raise additional funds to support some of the site’s still-operational research instruments, including its 12-meter radio telescope, its solar radio spectrometer and its Lidar facility, which uses lasers to probe the upper atmosphere.

For now, though, it’s unclear whether the Arecibo Observatory will continue to function as a research site in any capacity. The observatory currently employs more than a dozen on-site scientists, who were unavailable to comment on the NSF’s announcement. It also employs engineers, who keep the existing instruments operational, and dozens of other staff members, from groundskeepers to building maintenance workers. “Most of those people will be out of jobs,” Méndez says.

“NSF is grateful to current and past employees of the Arecibo Observatory, who have been integral to the outstanding work at the site,” the NSF spokesperson wrote. The agency is extending the observatory’s current funding award by an extra six months to September 2023 “to provide additional time to support the transition to the proposed new Center.”

For now, the exact future of the Arecibo Observatory remains uncertain. But barring a massive fundraising campaign or a coordinated push to Congress, Méndez says, it’s unlikely that anything like the Arecibo telescope will ever be rebuilt in Puerto Rico.

“Arecibo occupies a very special place in the hearts of a lot of astronomers,” Siemion says. “Although maybe it was an expected day, it nevertheless is a sad day. It’s definitely the end of an era.”

ABOUT THE AUTHOR(S)

Daniel Leonard is a freelance science journalist and former Scientific American editorial intern whose work focuses on space, tech and natural history. Follow Leonard on Twitter @dalorleon

Puerto Rico’s Arecibo telescope, once world’s largest, collapses | Science and Technology News

For five decades, Arecibo was the largest single-aperture telescope in the world, used to study distant planets and find asteroids.

The massive telescope on the Caribbean island of Puerto Rico – located at the Arecibo Observatory and deteriorating since August – collapsed on Tuesday, officials said, after 57 years of astronomical discoveries.

The radio telescope’s 900-tonne instrument platform, suspended by cables 137m (450 feet) above a 305-metre-wide (1,000-foot) bowl-shaped reflector dish, fell on Tuesday morning, the United States’ National Science Foundation (NSF) said. No injuries were reported, it added.

The instrument platform of the 305m telescope at Arecibo Observatory in Puerto Rico fell overnight. No injuries were reported. NSF is working with stakeholders to assess the situation. Our top priority is maintaining safety. NSF will release more details when they are confirmed. pic.twitter.com/Xjbb9hPUgD
— National Science Foundation (@NSF) December 1, 2020

The telescope, one of the largest in the world, had been used by scientists around the globe for decades to study distant planets, find potentially hazardous asteroids and hunt for potential signatures of extraterrestrial life.

It was also featured in two US films, GoldenEye starring Pierce Brosnan as James Bond and released in 1995, and Contact, with actors Jodie Foster and Matthew McConaughey two years later.

The Arecibo Observatory space telescope, seen in a satellite image taken over Arecibo, Puerto Rico [File: Planet/Handout via Reuters]

Two cables supporting the reflector dish had broken since August, leaving a gash in the dish and making the site unsafe, forcing officials to close the observatory. The NSF, which helped manage the telescope, said in November that efforts to repair the structure would be too dangerous and therefore it would have to be demolished.

“NSF is saddened by this development,” the independent federal agency wrote on Twitter. “As we move forward, we will be looking for ways to assist the scientific community and maintain our strong relationship with the people of Puerto Rico.”

When it announced the closure last month, the NSF said that “the telescope serves as an inspiration for Puerto Ricans considering education and employment in STEM [science, technology, engineering and mathematics]”.

In the same statement, Michael Wiltberger, head of NSF’s Geospace Section, said the observatory “has helped transform our understanding of the ionosphere, showing us how density, composition and other factors interact to shape this critical region where Earth’s atmosphere meets space”.

The NSF’s original plan was to dismantle the site with “aims to retain as much as possible of the remaining infrastructure of Arecibo Observatory, so that it remains available for future research and educational missions”.

The largest radio telescope in the world.

Remember 10 years ago there was a movie about James Bond – “Golden Eye”. There, just the actions were unfolding on this telescope.

Many probably thought that this was the scenery for the film. And the telescope had already been operating for 50 years by that time

The Arecibo Observatory is located at an altitude of 497 meters above sea level. Although located in Puerto Rico, it is used and funded by various US universities and agencies. The main purpose of the observatory is research in the field of radio astronomy, as well as observation of space bodies. For these purposes, the world’s largest radio telescope was built. The diameter of the dish is 304.8 meters. nine0007

The depth of the dish (reflector mirror according to scientific) is 50.9 meters, the total area is 73,000 m2. It is made of 38778 perforated (perforated) aluminum plates laid on a grid of steel cables.

A massive structure, a mobile irradiator and its guides are suspended above the dish. It is supported by 18 cables stretched from three support towers.

If you buy an admission ticket for a $5 tour, you will get the opportunity to climb the irradiator in a special gallery or in the lift cage. nine0003

The construction of the radio telescope began in 1960, and already on November 1, 1963, the observatory was opened.

During its existence, the Arecibo radio telescope distinguished itself by the fact that several new space objects were discovered (pulsars, the first planets outside our solar system), the surfaces of the planets of our solar system were better studied, and also, in 1974, a message was sent Arecibo, in the hope that some extraterrestrial civilization will respond to him. We are waiting. nine0007

This survey turns on a powerful radar and measures the response of the ionosphere. An antenna of this large size is necessary because only a small fraction of the scattered energy reaches the measurement dish. Today, only a third of the telescope’s operating time is devoted to studying the ionosphere, a third to studying galaxies, and the remaining third is devoted to pulsar astronomy.

Arecibo is no doubt an excellent choice for finding new pulsars, as the telescope’s sheer size makes searches more productive, allowing astronomers to find hitherto unknown pulsars that are too small to be seen with smaller telescopes. However, these dimensions also have their disadvantages. For example, the antenna must remain fixed to the ground due to the inability to control it. As a result, the telescope is able to cover only the sector of the sky that is directly above it in the path of the earth’s rotation. This allows Arecibo to observe a relatively small portion of the sky, compared to most other telescopes, which can cover 75 to 90% sky.

The second, third and fourth largest telescopes that are (or will be used) for pulsar research are the National Radio Astronomy Observatory (NRAO) in West Virginia, the Max Planck Institute Effelsburg Telescope, and the NRAO Green Bank Telescope, respectively. Also in West Virginia. All of them have a diameter of at least 100 m and are fully controllable. A few years ago, the 100-meter NRAO antenna fell to the ground, and work is underway to install a better 105-meter telescope. nine0007

These are the best telescopes for studying pulsars outside the range of Arecibo. Note that Arecibo is three times the size of 100-meter telescopes, which means that it covers an area 9 times larger and achieves scientific observations 81 times faster.

However, there are many telescopes less than 100 meters in diameter that are also successfully used to study pulsars. Among them are Parkes in Australia and the 42-meter NRAO telescope.

A large telescope can be replaced by combining several smaller telescopes. These telescopes, more precisely networks of telescopes, can cover an area equal to that covered by hundred-meter antennas. One of these networks, created for aperture synthesis, is called the Very Large Array. It has 27 antennas, each 25 meters in diameter.

Since 1963, when the construction of the Arecibo Observatory in Puerto Rico was completed, the radio telescope of this observatory, with a diameter of 305 meters and an area of 73,000 square meters, has been the largest radio telescope in the world . But soon Arecibo may lose this status due to the fact that in the province of Guizhou, located in southern China, the construction of a new radio telescope Five-hundred-meter Aperture Spherical radio Telescope (FAST) has begun. When this telescope is completed, scheduled for completion in 2016, FAST will be able to “see” space at three times the depth and process data ten times faster than the Arecibo telescope’s equipment. nine0003

FAST was originally slated to participate in the international Square Kilometer Array (SKA) program, which will combine signals from thousands of smaller radio telescope antennas spaced 3,000 km apart. As we know at the moment, the SKA telescope will be built in the southern hemisphere, but where exactly, in South Africa or Australia, will be decided later.

Although the proposed FAST telescope project did not become part of the SKA project, the Chinese government gave the green light to the project and provided funding of 107.9million dollars to start building a new telescope. Construction began in March in Guizhou Province, in southern China.

Unlike the Arecibo telescope, which has a fixed parabolic system that focuses radio waves, the FAST telescope’s cable network and parabolic reflector design system will allow the telescope to change the shape of the reflector surface in real time using an active control system. This will be possible thanks to the presence of 4400 triangular aluminum sheets, from which the parabolic shape of the reflector is formed and which can be aimed at any point in the night sky. nine0003

The use of special modern receiving equipment will give the FAST telescope an unprecedentedly high sensitivity and high processing speed of incoming data. With the help of the antenna of the FAST telescope, it will be possible to receive signals so weak that it will be possible to “consider” with its help neutral clouds of hydrogen in the Milky Way and other galaxies. And the main tasks that the FAST radio telescope will work on will be the detection of new pulsars, the search for new bright stars and the search for extraterrestrial life forms. nine0003

sources
grandstroy.blogspot.com
relaxic.net
planetseed.com
dailytechinfo.org

The legendary Arecibo

telescope collapsed in Puerto Rico

Published: 02/12/2020 – 21:06

AP telescope collapsed in Puerto Rico – Yamil Rodriguez

nine0002
The legendary 305-meter Arecibo telescope, which was one of the largest in the world, collapsed in Puerto Rico. It was from him that in 1974 a radio signal was sent with data on human DNA in the direction of the constellation Hercules, intended for aliens.

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The Arecibo radio telescope was a spherical reflector larger than 300 meters inside a funnel and 900 ton mobile platform. Its movement made it possible to point the telescope at various constellations. The system was built in the late 1950s and made it possible not only to obtain information about a number of stars and planets, but also to send a radio signal to aliens. On November 16, 1974, information about human DNA, as well as the solar system and chemical elements on the planet, was sent to the constellation Hercules, located more than 25 thousand light years from Earth. The message lasted 169 seconds and consisted of 1679 digits. nine0003

The unusual shape of the telescope has attracted the attention of filmmakers from all over the world. The structure was featured in the final shots of the James Bond movie GoldenEye. The Arecibo radio telescope was also the star of the sci-fi films Contact by Robert Zemeckis (1997), Arrival by David Twohy (1996), The X-Files episode “The Little Green Men” and several other films.

Problems with Arecibo began in the summer of 2020. Then the auxiliary cable broke and punched a hole in the antenna. After that, one of the supporting cables fell, which made the structure dangerous for researchers and workers. On November 20, the work of the telescope was stopped. nine0003

Muy tristes las fotos desde el Observatorio de Arecibo. pic.twitter.com/7gByZLdPFF
— Deborah Martorell (@DeborahTiempo) December 1, 2020

The unusual shape of the telescope has attracted the attention of filmmakers from all over the world. The structure was featured in the final shots of the James Bond movie GoldenEye.

Photographs of the collapsing telescope show that the fallen platform and cables have punched several holes in the reflector. Whether the structure, which has served for more than 50 years, will be restored is not reported.

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