Arecibo telescope faces catastrophic collapse, must be deconstructed

One of the world’s most iconic astronomical observatories has collapsed beyond repair. Now he threatens to completely collapse.

Following two unexpected cable breaks, engineers determined that Arecibo’s 1,000-foot (305-meter) radio telescope is so structurally unhealthy that any worker attempting to fix it would risk their life. So the National Science Foundation, owner of the Puerto Rico telescope, decided to put it out of service.

Now engineers are struggling to figure out how to safely dismantle one of the world’s largest radio telescopes before it collapses on itself. The structure is so unstable that engineers cannot even approach it to assess the risk and timing of such a collapse.

“Even attempts to stabilize or test the cables could accelerate the catastrophic failure,” Ralph Gaume, director of the NSF’s Astronomical Sciences Division, said at a press conference Thursday morning.

“ It’s like losing someone important in your life ”

During its 57-year life, the Arecibo Telescope chased dangerous asteroids near Earth, searched for signs of alien life, and discovered the first planet beyond our solar system. In 1974, Arecibo aired the most powerful program ever sent by Earth to communicate with potential aliens. In 2016, it detected the first repeated rapid radio bursts – mysterious signals from space that scientists say now come from dead stars.

But Arecibo’s woes began in August, shortly after Tropical Storm Isaias hit the island. A 3-inch-thick auxiliary cable came out of its socket on one of the telescope’s three towers and crashed into the reflector antenna below. He tore a 100-foot gash in the panels.

Arecibo Observatory

Then in early November, just before repairs began in earnest, a 15,000-pound trunkline from the same tower broke and crashed into the antenna. Engineers had thought the structure was still strong enough to prevent a second disaster – and this cable was only carrying 60% of its estimated load capacity – but the failure proved them wrong. They decided they could no longer trust any of the remaining cables.

The two failed cables supported a huge metal platform suspended above the antenna. If another cable from the same tower failed, engineers discovered that the platform would fall with it.

“The entire 900-ton platform is going to crash into the main drive, and there is a possibility that the three main towers themselves, which are over 300 feet tall, topple over,” Gaume said.

Universal Images Group via Getty Images

Deconstructing the telescope means giving up any chance of saving it, but that’s the course of action recommended by three engineering firms.

“This decision is not an easy one for the NSF. But the safety of people is our number one priority,” said Sean Jones, deputy director of the Mathematical and Physical Sciences Branch of the NSF.

By moving quickly, the NSF hopes to recover a set of buildings that were directly under one of the telescope towers. In this way, the Arecibo Observatory can remain open – but without its defining characteristic.

“When I heard the news, I was totally devastated,” Abel Mendez, director of the Planetary Habitability Laboratory at the University of Puerto Rico at Arecibo, told Business Insider. He has been around the observatory since the age of 10 and has worked with it professionally for the past decade.

“It’s hard to take. It’s like losing someone important in your life. Yeah, 2020 – that’s not good,” he said.

The United States has lost its best asteroid hunter and alien researcher

The loss of the Arecibo telescope is a huge blow to the search for extraterrestrial humanity, our ability to defend the planet from asteroids and the whole field of radio astronomy.

Mendez said that while Arecibo does not discover any potentially dangerous space rocks, it is essential to study them: the observatory can ping these objects with radar to decipher their shape, rotation, surface characteristics and their trajectory in space.

Don Davis / NASA

Without this data, it is much more difficult to know if an asteroid is heading towards Earth.

The Arecibo observatory plans to work with scientists who intended to use the telescope to find ways to transfer their research elsewhere, Gaume said. Other NSF facilities – the National Radio Astronomy Observatory in Virginia and the Green Bank Observatory in West Virginia – could potentially support some Arecibo sciences.

However, Mendez said Green Bank is only 10% to 20% as sensitive to weak radio signals as Arecibo. He therefore believes that the telescope’s death effectively ends the United States’ chance to conduct a global research project for radio waves from extraterrestrial technologies.

“The only place we have to do something like this, which would be sensitive or more sensitive than Arecibo, is now FAST in China,” Mendez said, referring to the five hundred meter aperture spherical radio telescope in Guizhou province. . “The United States has lost all of this capacity because it doesn’t have Arecibo.”

Arecibo and FAST, Mendez said, were Earth’s “two big eyes” in radio astronomy.

“If you are monitoring a source of interest that is in the low radio spectrum, you need two large radio telescopes: one pointing at something during the day and the other at night,” he said. Explain. “If you lose Arecibo, you lose the ability to monitor – 24 hours a day – a weak source of radio signals.”

He added: “Now we only have one eye.”

‘We are working against the clock’

It will likely take about five to six weeks to figure out how to safely deconstruct the Arecibo telescope. Engineers will be weighing their options from afar, with drones taking aerial photos.

Engineers are also considering ways to save time, such as tilting the towers a few inches to reduce the weight of the remaining cables.

“We are working against the clock,” said Gaume.

The technical reports announcing the death of Arecibo are integrated below.

If engineers can take the telescope apart before it destroys itself, the Arecibo Observatory will still be able to conduct scientific research. Its LIDAR lasers can study the Earth’s upper atmosphere and ionosphere. It also has a facility on Culebra Island that collects data on cloud cover and precipitation.

Future researchers could also still analyze the telescope’s archived data.