One of the most powerful telescopes in the world is on the brink of collapse.
Arecibo, a giant radio observatory nestled in the lush mountains of Puerto Rico, did some of the dreamiest work in astronomy. But it was forced to stop operations this year after suffering unprecedented damage, and officials now believe that it is beyond repair. Instead of trying to fix it, they’re going to tear it down.
The trouble began in August. A metal support cable weighing thousands of pounds slipped out of its socket and plummeted into the cavernous, 1,000-foot-wide radio dish in the middle of the night. The cable, installed in the 1990s, was considered fairly new for an observatory that began operations in 1963, and the incident confounded Arecibo’s stewards. The cable “definitely should not have failed in the way it did,” Ashley Zauderer, the Arecibo program director at the National Science Foundation,which owns the telescope, said during a press conference today.
By the time the sun rose the next day, the telescope was transformed. The great Arecibo, where the fictional astronomer Ellie Arroway scanned the cosmos for unexplainable phenomena in Contact—and where countless real astronomers did the same—now resembled a crumbled set from an apocalyptic disaster movie.
Officials were hopeful they could repair the damage, and outlined a plan. But earlier this month, just days before engineers were scheduled to try to stabilize the telescope, another piece of hardware came smashing into the dish. A main cable, one of the originals installed when the observatory was built, had snapped, causing even more damage. Engineers had recently inspected the cable, and though they saw that some of its exterior wires had torn, they thought it was strong enough to hang on. “It was just not seen as an immediate threat, and I don’t think anyone understood that clearly the cable had deteriorated,” Zauderer said. The gut punch is that this main cable was scheduled to be replaced this year.
The Arecibo Observatory faces an “uncontrolled catastrophic collapse,” Ralph Gaume, the director of the astronomy division at the NSF, told reporters this morning. The structure is so unsteady that it’s too dangerous for engineers to inspect it up close. “According to engineering assessments, even attempts at stabilization or testing the cables could result in accelerating the catastrophic failure,” Gaume said. Engineers fear that more cables could break and crash into the dish.
Arecibo has provided observations for discoveries within the solar system and well beyond. It is considered a landmark in the field of SETI, the search for extraterrestrial intelligence, and one of the best spots for studying potentially hazardous asteroids near Earth.
Over the years, Arecibo has built a reputation as a resilient institution; it has faced danger and damage, but it has always endured. In its lifetime, it has survived earthquakes and storms, including the hurricane that devastated Puerto Rico in 2017, which damaged some of the dish. This year, a month before the first cable failure presaged Arecibo’s downfall, the observatory weathered a tropical storm in silence and then powered up as soon as the skies cleared, ready to chase an asteroid as it zoomed past Earth. Even after the second cable broke this month, officials wanted badly to save the telescope. “It’s just too important of a tool for the advancement of science,” Francisco Cordova, the observatory’s director, said at the time. The expectation was that Arecibo would bounce back yet again.
Engineers are now working to quickly formulate a plan to demolish the telescope before it collapses on its own. Arecibo’s demise is a different fate than astronomers are used to. Hardware of all sorts ages and breaks—Hubble, another famed telescope, is operating with fewer working parts than it launched with 30 years ago. But it is unusual to wreck an observatory because you have no other choice, and so unexpectedly too. Engineers have deliberately destroyed spacecraft before, such as Cassini, which plummeted into the atmosphere of Saturn, and Galileo, which met a similar end on Jupiter, but those goodbyes were planned. Scientists had the chance to make their final observations and close up shop. The spacecraft were running out of fuel, and soon their scientific instruments would fall silent. Their missions were over. Arecibo’s was not.