"The decision comes after NSF evaluated multiple assessments by independent engineering companies that found the telescope structure is in danger of a catastrophic failure and its cables may no longer be capable of carrying the loads they were designed to support," the NSF said in a statement.
A second cable failed in early November. This one was a main cable and it broke and fell into the reflector dish, damaging both the dish and other cables nearby. The cables were designed to support a 900-ton platform that hangs 450 feet above the dish.
"Each of the structure's remaining cables is now supporting more weight than before, increasing the likelihood of another cable failure, which would likely result in the collapse of the entire structure," the University of Central Florida said in a statement on Nov. 13. UCF manages the facility for the National Science Foundation.
The observatory was the backdrop to a dramatic fight scene in the 1995 James Bond movie GoldenEye with Pierce Brosnan. It also appeared in the 1997 Jodie Foster movie Contact. But Arecibo's true legacy lies in the many scientific discoveries it made possible. It explored pulsars, expanded our knowledge of Mercury, spotted exoplanets and found fast radio bursts.
Field geophysicist Mika McKinnon tweeted, "I'm stunned that we're losing Arecibo. Even if you don't pay much attention to ground-based astronomy, you know this telescope from pop culture & movies. It's somewhere special."
The NSF decommissioning plan will focus on the telescope while attempting to preserve surrounding observatory structures. "When all necessary preparations have been made, the telescope would be subject to a controlled disassembly," the foundation said.