After Suffering Irreparable Damage, It’s Lights Out for the Arecibo Observatory’s Iconic Telescope

The 1,000-foot telescope has been a pillar for astronomical research, leading to some of the cosmos’ most exciting discoveries

A photograph of the dish from high above. It has three tall towers around the circular dish, all connected by thick cables. The dish has a 100-foot hole on the side. The observatory is surrounded by expansive forest.
Teams of engineers looked for remedies to help save the telescope, but repairs would be too risky for a construction team to safely undertake. University of Central Florida

After 57 years of gazing into the universe and helping astronomers unravel the cosmos' mysteries, the Arecibo Observatory's world-renowned telescope in Puerto Rico will be torn down, reports Alexandra Witze for Nature.

The observatory has three towers equipped with cables that hold up the telescope's enormous, 1,000-foot reflector dish. In 2017, Hurricane Maria battered the already deteriorating telescope. This August, an auxiliary cable slipped out of its socket, inflicting a 100-foot-long gash in the dish. Three months later, a main cable connected to that same tower snapped, causing more devastating damage. Teams of engineers looked for remedies to help save the telescope, but repairs would be too risky for a construction team to safely undertake, reports Ashley Strickland for CNN.

Given the age of the telescope, it would need more intensive maintenance in the future since the cables were weaker than originally thought. For this reason, the National Science Foundation (NSF) announced yesterday that plans to decommission the telescope were underway.

"There is a serious risk of an unexpected and uncontrolled collapse," Ralph Gaume, the director of NSF’s astronomy division, said in an NSF telephone conference yesterday. "A controlled decommissioning gives us the opportunity to preserve valuable assets that the observatory has."

More cables could fail at any second, which could destroy the whole dish and jeopardize the safety of people at the observatory. A controlled breakdown of the telescope allows the NSF to safely lower it, reports Elie Levine for NPR.

For 53 years, Arecibo was the world's largest radio telescope until it was superseded by a 1,600-foot telescope built in China in 2016. During its reign, the powerful telescope led to discovery after discovery, challenging what scientists knew about outer space. Some of its highlights include: learning that Mercury completes one rotation every 59 days, not 88 days as originally thought; becoming a hotspot for research on extraterrestrial life; and discovering a pair of pulsars, or super-magnetized rotation stars, orbiting the Earth, reports Dennis Overbye for the New York Times.

"It is very sad to witness the passing of this scientific Queen," Jill Tarter, who used to search for aliens at the observatory, writes in an email to the Times. "She withstood powerful hurricanes, but age appears to have gotten the upper hand."

The NSF will swiftly begin to decommission the telescope before any more dangers arise or damages take place. The whole observatory will not be shut down, though. NSF recognizes its importance to Puerto Rico and to Science, so they will try to safeguard it as a research center that can be used again in the future, reports Meghan Bartels for

"While I am disappointed by the loss of investigative capabilities, I believe this process is a necessary step to preserve the research community's ability to use Arecibo Observatory's other assets and hopefully ensure that important work can continue at the facility," says Michael Wiltberger, head of NSF's Geospace Section, in a press release.

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