Arecibo Observatory will be torn down because repairs are too dangerous

NSF can't carry out repairs without putting human lives at risk.

University of Central Florida

After 57 years of helping to expand human knowledge and understanding of the cosmos, the story of Puerto Rico’s world-famous Arecibo Observatory is coming to an unfortunate end. Following two cable failures in recent months, the National Science Foundation (NSF), the agency that oversees the telescope, announced on Thursday it has no choice but to decommission the structure.

The NSF commissioned multiple independent evaluations to determine how to go about repairing Arecibo. They all came to the same conclusion: the 900-ton structure that hangs over the observatory’s iconic dish is at risk of “catastrophic failure,” and attempting to repair it would put both construction workers and the staff’s facility at life-threatening risk. Moreover, even if workers could somehow carry out repairs safely, there’s no guarantee the observatory won’t have long-term stability issues.

"Until these assessments came in, our question was not if the observatory should be repaired but how. But in the end, a preponderance of data showed that we simply could not do this safely. And that is a line we cannot cross," said Ralph Gaume, director of the NSF’s Astronomical Sciences division.

The agency says it will demolish the 1000-foot telescope, while attempting to preserve as many of the surrounding structures as possible, including the nearby visitor center. NSF didn’t say how long the process will take, nor how much it will cost to do. It’s small solace, but not everything is lost. The agency hopes to continue work at the observatory’s LIDAR facility, as well as the nearby offsite Culebra facility, which collects data on clouds and rainfall. It will also continue to analyse and catalog data scientists collected with the telescope before it was ultimately taken out of action.

To say the loss of Arecibo is a major blow to the scientific community, would be an understatement. Researchers with the Search for Extraterrestrial Intelligence (SETI) used the telescope to search for signs that humanity is not alone among the stars. It also helped scientists keep track of dangerous asteroids, as well as study distant cosmic events like pulsars and gravitational waves.