The instrument platform of the 305-meter telescope at Arecibo Observatory in Puerto Rico collapsed overnight, according to the National Science Foundation.
It’s a final blow to one of the most powerful telescopes on Earth that has aided astronomical discoveries for 57 years and withstood hurricanes, earthquakes and tropical storms.
Engineers assessed the damage and determined that all three of the telescope’s support towers broke off, sending the 900-ton instrument platform plummeting down to the dish below. The telescope’s support cables also dropped. The observatory’s learning center was significantly damaged by the falling cables as well.
The collapse occurred just weeks after NSF announced that the telescope would be decommissioned and disassembled through a controlled demolition after sustaining irreparable damage earlier this year.
“The instrument platform of the 305m telescope at Arecibo Observatory in Puerto Rico fell overnight. No injuries were reported. NSF is working with stakeholders to assess the situation. Our top priority is maintaining safety. NSF will release more details when they are confirmed,” according to a tweet by the National Science Foundation.
“NSF is saddened by this development. As we move forward, we will be looking for ways to assist the scientific community and maintain our strong relationship with the people of Puerto Rico,” the foundation said in another tweet.
The spherical radio/radar telescope includes a radio dish 1,000 feet across and a 900-ton instrument platform suspended 450 feet above it. Cables connected to three towers hold the telescope in place.
“We are saddened by this situation but thankful that no one was hurt,” said NSF Director Sethuraman Panchanathan in a statement. “When engineers advised NSF that the structure was unstable and presented a danger to work teams and Arecibo staff, we took their warnings seriously and continued to emphasize the importance of safety for everyone involved. Our focus is now on assessing the damage, finding ways to restore operations at other parts of the observatory, and working to continue supporting the scientific community, and the people of Puerto Rico.”
An auxiliary cable came loose from a socket on one of the towers in August, creating a 100-foot gash in the dish. Engineers were assessing and working on a plan to repair the damage when another main cable on the tower broke on November 6.
When it broke, the cable crashed into the reflector dish below, causing additional damage.
After the break on November 6, engineers inspected the rest of the cables and discovered new breaks as well as slippage from some of the sockets on the towers. Multiple engineering companies reviewed the damage. They determined that the telescope could collapse because it is “in danger of catastrophic failure” and the cables were weaker than expected.
The latest review revealed that damage to the telescope could not be stabilized without risking staff and the construction team. This led to the NSF making the decision to decommission the telescope after 57 years.