One of the world’s most respected radio telescopes, on the verge of destruction, has begun a race to uncover it by engineers at the Arecibo Observatory in Puerto Rico after two complex cables supporting a 900-ton instrument platform broke.
The platform, in which a large dish was made by cables fluttering from the towers, must freeze quickly, or it could break to the ground and destroy the telescope. With the loss of these two cables, the remaining cables are under increasing stress, and rescue efforts are sure to be successful.
“For me, it’s probably fifty-fifty,” says Michael Nolan, now the former observatory director at the University of Arizona. “They are doing what can be done. I’m still really worried they won’t be able to do enough. If we worry about her falling, no one should go there or be there when it happens. ‘
Suspended from the three towers, the telescope’s platform rotates about 500 feet above the thousand-foot-wide dish. In August Gust, the auxiliary cable slipped out of its socket and sank into the dish, carving a 100-foot-long gauze into its reflective panels. Before the crew could repair the cable, another one attached to the same tower collapsed on November 6. This second broken cable is one of the four primary things that connect that tower to the platform.
“I wasn’t worried when the first cable failed, because I was confident it would take a few months to recover,” says Abel Mendez, an astronomer at the University of Puerto Rico in Arecibo who frequently observes with a telescope. But Mendez says he was stunned when the second cable failed. “I’m worried now.”
Arecibo has played a crucial role in seeing planets other than our solar system, discovering extraterrestrial cultures, and studying asteroids and other worlds close to home. Today, scientists use telescopes to study powerful radio bursts called rapid radio bursts and to spy on space-time fabrics that have been formed to collide with galaxies.
The platform suspended on Arecibo’s radio dish contains many of the observatory’s scientific equipment, and is in danger of collapsing after two cables supporting the constitution fail.
Photograph by Xavier Garcia, Bloomberg by Getty Images
Each tower of the observatory has four primary cables, but only two are needed to keep the platform alone – assuming they are in the right shape. Tower four (named because it is at a four o’clock position if the afternoon is north) is now only three primary. If one of the cables fails, it is unclear whether the two older cables will be able to hold the platform.
“It’s an ugly situation for sure,” says Frank Drake, a former Arecibo director (and my father). “When you have cables like this broken, it causes the chain reaction to break more cables at any moment, and cause the whole thing to fall down.”
It will be a major blow to ongoing science observations and to Puerto Rico, where the observatory is equally proud, provides employment, attracts tourists and shares resources with surrounding communities, especially during a crisis like Hurricane Maria.
Multiple engineering companies and U.S. Army Corps of Engineers engineers are on the ground evaluating the endangered platform, while daily drone inspections provide updates on cables. Teams are exploring ways to stabilize the structure, including using a helicopter to remove a small amount of weight from the platform, lowering the platform to remove tension from the system, and reconnecting a fallen support cable that remains largely intact even after slipping out of its socket.
“We’ll probably report very soon if they can take the band-aid, remove some of the tension, remove the immediate problem, so we can solve the big problem.”
Cutting the cable
In the 1960s, engineers built a huge radio dish of Arecibo in one of Puerto Rico’s natural sinholes. An overhead, triangular instrument platform helps target telescopes in different parts of the universe. That platform is packed with receivers, line feeds, and a complex reflector system that focuses precisely on radio waves – and that’s where James Bond fought Alec Trevelion in the 1995s. Golden New.
Although it may seem small compared to a dish, the suspended structure is really spacious – a small house can easily fit inside a domed reflector system.
The platform is wrapped in three concrete towers made of 18 thick, steel cables, the highest of which is 365 feet in size. In addition to the four primary cables on each tower, two auxiliary devices per tower were installed in the 1990s to stabilize the structure and bear the extra weight.
Observatory staff regularly inspect towers, cables and platforms to detect any signs of weakening or corrosion due to saline, tropical air.
“There’s nothing worse than salt fog,” says Dennis Egan, an engineer at the Green Bank Observatory in West Virginia. “It’s better to stay underwater.”
These observations have yielded some evidence of stranded pads in cables, a problem that could be exacerbated by Nolan’s suspected hurricane Maria and the recent large-scale earthquake. But they found no sign of widespread weakness or impending failure. In a question and answer posted on Facebook, Arecibo’s director, Francisco Cordova, said the crash was unexpected and an indicator of structural deterioration.
The observatory is “500 years old, and there has never been a situation where a bunch of different strands suddenly break,” says Drake, who famously sent a message from the observatory in 1974 into outer space. Now on to that thing. There is no escape. You just hung up. “
If Tower Four fails, the platform can either crash through the dish or swing the pendulum into a nearby cliff. Without balancing the towers without the weight of the platform, it is possible for all three to slip into the surrounding forest.
If engineers can stabilize the structure, they will then be able to repair or replace some of the older cables. Cardova said on Facebook that two new cables are on order due to arrive at the observatory in December.
But to replace the cables, workers have to go to the platform. “They have to do something to check that the existing cables are proper and unnecessary, in a way that doesn’t endanger the people on the structure,” says Drake.
A scientific and cultural icon
The Arecibo Observatory has faced a number of challenges over the past few years, including threats of yanke funding from the National Science Foundation. But scientists and the surrounding community rallied, and the University of Central Florida stepped in to operate the established observatory.
Now, many are wondering whether the NSF will help Arecibo during this crisis. According to Cardova’s social media post, the NSF is reviewing a request for $ 12.5 million in repair funding.
“The NSF is in talks with Arecibo. We are monitoring the situation and considering all possible options to accelerate the stability of the structure, ”the agency said in a statement. “Our top priority is the health and safety of Arecibo staff.”
Despite its current difficulties, the observatories have a long and orthodox history, which has earned scientists and Puerto Ricans pride.
Edgard Rivera-Valentન્ટn, of the Institute of Lunar and Planetary Sciences, says, “He immersed himself in our culture in our everyday life, in Puerto Rico, whose grandfather helped build the telescope. Rivera-Valentરાn says,” And I definitely remember knowing that people in my city are really doing all these great things. “I’m in science because I grew up near the observatory.”
Aresibo’s discovery includes the discovery of a pair of orbiting pulsars in 1974 that emit gravitational waves – won the Nobel Prize in Physics in 1993 – and the first confirmed planets orbited stars other than the Sun in 1992. Scientists from Arecibo also discovered the planet Mercury. Rotation rates, repeated rapid radio explosions were observed, and numerous searches were conducted for cultures outside the conversation, an attempt popularized by Carl Sagan’s novel. Contact It then became a movie of the same name.
In addition to observing the heavens and collecting radio waves, the Ci Resibo is also an extremely powerful radar. Scientists use this ability to characterize asteroids that cross Earth’s orbit, calculating their position with great precision to figure out how to avoid future collisions. And in 1974, Dad used it to send an international message to the star cluster known as the Great Cluster in the constellation Hercules. In it, he encoded information about humans, the Earth, the solar system, and Arecibo and broadcast it during a celebration of the upgrade to the telescope.
“He does atmospheric science, he does solar science, he does astronomy, he does astrophysics,” says Rivera-Valentin. “It’s important for science and for the whole world.”
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