Today, the National Science Foundation (NSF) released shocking footage of the collapse of the Arecibo Observatory in Puerto Rico. The video, captured on December 1st, shows the moment when support cables snapped, causing the massive 900-ton structure suspended above Arecibo to fall onto the observatory’s iconic 1,000-foot-wide dish.
The videos of the collapse were captured by a camera located in Arecibo’s Operations Control Center, as well as from a drone located above the platform at the time of collapse. The operator of the drone was able to adjust the drone camera once the platform started to fall and capture the moment of impact. NSF, which oversees Arecibo, had been doing hourly monitoring of the observatory with drones, ever since engineers warned that the structure was on the verge of collapsing in November. “I think we were just lucky and the drone operator was very adept to see what was happening and be able to turn the camera,” Ashley Zauderer, the NSF program manager for Arecibo Observatory, said during a press conference.
The footage highlights the moment when multiple cables snapped, causing the platform to swing outward and hit the side of the dish. The collapse also brought down the tops of the three support towers surrounding Arecibo, where the cables had been connected to keep the platform in the air. “The cables that go from the top of Tower 4 to the platform — they’re very faint in the camera view but they’re there,” said John Abruzzo, a contractor at engineering consulting firm Thornton Tomasetti, hired by the University of Central Florida. “And so it’s those cables that fail near the tower top first, and then once those fail, the platform then loses stability and starts to come down,” Abruzzo said, describing the first video from the control center.
The collapse of Arecibo didn’t come as a surprise. Following the failure of two support cables in both August and November, engineers had concluded that there was no safe way to repair Arecibo and that the platform could fall onto the dish at any moment. NSF hoped to do a controlled demolition of the telescope before that happened, but the collapse occurred before any kind of action could take place.
Now NSF is trying to figure out a path forward, which mostly revolves around figuring out how to clean up Arecibo in a safe manner. Engineers need to do a full environmental assessment of the area and figure out how stable the remaining structures are.
Replacing Arecibo would be a much longer process, involving decisions from lawmakers. “With regards to replacement, NSF has a very well defined process for funding and constructing large scale infrastructure — including telescopes,” Ralph Gaume, director of NSF’s division of astronomical sciences, said. “It’s a multi-year process that involves congressional appropriations, and the assessment and needs of the scientific community. So it’s very early for us to comment on the replacement.”