The iconic Arecibo Observatory in Puerto Rico has been destroyed after a 900 tonne metal platform suspended above the telescope collapsed around 8 a.m. local time today. The National Science Foundation (NSF) says that no injuries have been reported and that it is now “working with stakeholders to assess the situation”.
Since it opened in 1963, the Arecibo Observatory has been crucial for radio astronomy and at 305 m wide was the world’s second-largest single-dish telescope. Although the telescope’s main uses were focused on radio astronomy, space weather and atmospheric science, it was also renowned for its planetary radar facility, which NASA used for near-Earth asteroid tracking and the characterisation of planetary surfaces.
On 10 August, however, one of the six 8 cm-wide auxiliary steel cables that support the telescope’s platform failed, tearing a 30 m gash through the main reflector dish as it flailed. The auxiliary cables were added in the 1990s to help balance the increased weight when the reflecting system was upgraded. Part of that upgrade involved installing the Gregorian Dome, which was also damaged as the cable crashed down.
Then on 6 November one of four main cables supporting the platform snapped with investigations showing that another two had wire breaks, increasing the likelihood of the tower platform falling and destroying the telescope. On 19 November, the NSF – one of the organizations that manages the observatory together with the University of Central Florida, Universidad Ana G Méndez and Yang Enterprises – decided to decommission the telescope on safety grounds.
Following the news, a “save the Arecibo Observatory” campaign began on social media as astronomers and members of the public also shared their thoughts on the closure using the Twitter hashtag #WhatAreciboMeansToMe. There was also a petition to the US government calling for emergency action to stabilize the telescope, which had been signed by almost 60,000 people.
Arecibo Observatory will be decommissioned, says US National Science Foundation
“[Arecibo’s] demolition or unplanned collapse presents the potential of an environmental emergency as it lies on top of an aquifer and would affect the nearby population,” the petition states. “We urge emergency action to have the Army Corps of Engineers or another agency evaluate the telescope structure and search for a safe way to stabilize it, to provide time for other actions to be considered and carried out.”
However, that now appears impossible after reports that the structure had collapsed (see below). “The Arecibo radio telescope platform has collapsed onto the dish, presumably the scenes are very messy on the ground,” noted James O’Donoghue, a planetary astronomer at the Japanese Aerospace Exploration Agency. “It’s a sad day for astronomy.”
The NSF says it is “saddened” by the 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,” it adds.
