[ad_1]
SAN JUAN, PUERTO RICO – Giant and obsolete cables supporting one of the largest single-disc radio telescopes in the world are slowly unveiling in this US territory, pushing an observatory renowned for its key role in astronomical discoveries on the verge of collapse.
The Arecibo Observatory, which is tethered atop a sinkhole in the lush mountainous region of Puerto Rico, boasts a 300-meter (305-meter) wide antenna featured in Jodie Foster’s “Contact” and James Bond film “GoldenEye”. The dish and a dome suspended above it were used to track asteroids headed to Earth, conduct research that led to the Nobel Prize, and helped scientists try to determine if a planet is habitable.
“As someone who depends on Arecibo for my science, I’m scared. It’s a very worrying situation right now. There is the possibility of a catastrophic cascade failure,” astronomer Scott Ransom said with the North American Nanohertz Observatory. for Gravitational Waves, a collaboration of scientists in the United States and Canada.
Last week, one of the telescope’s main steel cables that was capable of supporting 1,200 pounds (544 kilograms) snapped under just 624 pounds (283 kilograms). That failure further damaged the reflector after an auxiliary cable broke in August, tearing a 30-meter hole and damaging the dome above it.
Officials said they were surprised that they had assessed the facility in August and believed it could handle the weight shift based on previous inspections.
It is a blow to the telescope used by more than 250 scientists around the world. The property is also one of Puerto Rico’s top tourist attractions, attracting approximately 90,000 visitors annually. Research has been on hold since August, including a project that helps scientists search for nearby galaxies.
The telescope was built in the 1960s and funded by the Department of Defense in an effort to develop ballistic missile defenses. It has endured more than half a century of disasters, including hurricanes and earthquakes. Repairs from Hurricane Maria, which devastated Puerto Rico in 2017, were still ongoing when the first cable snapped.
Some new cables are expected to arrive next month, but officials said funding for the repairs has not been agreed with federal agencies. Scientists warn that time is running out. Only a handful of cables now support the 900-tonne platform.
“Each of the structure’s remaining cables now support more weight than before, increasing the likelihood of another cable failure, which would likely cause the entire structure to collapse,” said the University of Central Florida, which manages the structure. in a statement Friday.
University officials say crews noticed wire breaks on two of the remaining main cables. They warn employees and contractors are at risk despite relying heavily on drones and remote cameras to assess damage.
The observatory estimates the damage at over $ 12 million and is seeking money from the National Science Foundation, an independent federal agency that owns the observatory.
Foundation spokesman Rob Margetta said engineering and cost estimates have not been completed and that funding for repairs would likely involve Congress and stakeholder discussions. He said the agency is reviewing “all recommendations for action in Arecibo”.
“NSF is ultimately responsible for decisions regarding the safety of the facility,” he said in an email. “Our top priority is the safety of everyone on the site.”
Representatives from the university and the observatory said the telescope director, Francisco Córdova, was unavailable for comment. In a Facebook post, the observatory said the maintenance was up to date and the most recent external structural assessment occurred after Hurricane Maria.
The most recent damage was likely the result of degrading the cable over time and carrying extra weight after the auxiliary cable snapped, the university said. In August, the socket holding that cable failed, possibly due to a manufacturing error, the observatory said.
The problems disrupted the work of researchers such as Edgard Rivera-Valentín, a scientist with the Universities Space Research Association at the Lunar and Planetary Institute in Texas. He had planned to study Mars in September during its approach to Earth.
“This is the closest Mars it would have been while also being observable from Arecibo until 2067,” he said. “I won’t be there the next time we can get this level of radar data.”
The Puerto Rico observatory is considered crucial for the study of pulsars, which are the remains of stars that can be used to detect gravitational waves, a phenomenon predicted by Albert Einstein in his theory of general relativity. The telescope is also used to search for neutral hydrogen, which can reveal how certain cosmic structures are formed.
“It’s over 50 years old, but it remains a very important tool,” said Alex Wolszczan, a Polish-born astronomer and professor at Pennsylvania State University.
He helped discover the first exoplanets and pulsars and credited the observatory for having a culture that allowed him to test what he described as wild ideas that sometimes worked.
“Losing would be a huge blow to what I think is a very important science,” Wolszczan said.
An astronomer at the observatory in the 1980s and early 1990s, Wolszczan still uses the telescope for certain jobs because it offers an unparalleled combination of high frequency range and sensitivity that he believes allows for a “wide range” of scientific projects. Among them: the observation of the molecules of life, the detection of the radio emission of the stars and the conduct of the work of pulsars.
The telescope has also been a training ground for graduate students and widely loved for its educational opportunities, said Carmen Pantoja, an astronomer and professor at the University of Puerto Rico, the largest public university on the island.
She relied on it for her PhD thesis and recalled staring at it in wonder when she was a girl.
“I was struck by how big and mysterious it was,” she said. “The future of the telescope depends a lot on the position that the National Science Foundation takes … I hope they can find a way and that there is good will to save it.”
Source link
