The world-famous Arecibo Observatory has collapsed after sustaining significant damage.
The vast radio telescope in Puerto Rico was until recently the biggest in the world, and has helped look out into space both near and far, watching for objects that come close to the Earth as well as searching for alien life. It also became famous for its role in films including Goldeneye, which showed its 1,000-foot-wide dish.
But it has now collapsed, after sustaining damage that had already led its managers to conclude that it could not be fixed and would have to be retired.
The 900-ton receiver platform and Gregorian dome – the large structure that sat above the dish – fell down more than 400 feet onto the north part of the telescope below, onlookers said.
Onlookers described a large crash and a wave of emotions after it became clear that it had broken.
"It sounded like a rumble. I knew exactly what it was," Jonathan Friedman, who worked at the observatory for 26 years and lives nearby, told the Associated Press.
"I was screaming. Personally, I was out of control.... I don't have words to express it. It's a very deep, terrible feeling."
Friedman said that he had run up a hill overlooking the observatory, after hearing the noise, and saw a cloud of dust where the dish had once stood.
The observatories problems began in August, when a cable snapped and fell onto the dish, ripping a 100-foot hole in it and damaging the platform. Another cable broke in November, just as repairs on the original problems were beginning.
After those accidents, further examination showed that it would be impossible to safely and affordably fix the telescope, its administrators at the US National Science Foundation had already announced. That had led them to announce that it would be closed permanently, causing distress to scientists who have since been lobbying that funding should be made available for it to stay open.
Then, last weekend, wires started snapping on the observatory. And at 8am local time on Tuesday morning, the whole structure came down, as a result of what appeared to be a snowball effect of the breaking cables.
The Arecibo Observatory was originally built in the 1960s, when it was funded by the Defense Department. Building a new one could cost $350 million and the funds to do so would have to come from the US Congress.