Officials at the US National Science Foundation have decided to decommission the iconic Arecibo Observatory in Puerto Rico after a second cable failure caused fresh damage to the telescope’s metal platform, which is suspended above the 305 m-wide reflecting radio dish. According to a statement from the University of Central Florida, two of the remaining main cables seem to have wire breaks, increasing the likelihood of the tower platform falling and destroying the telescope.
Opened in 1963, the observatory is currently the world’s second-largest single-dish telescope. On 10 August one of the six 8 cm-wide auxiliary steel cables added in a 1990s upgrade failed. This tore a 30 m gash through the main reflector dish. Then on 6 November one of the dish’s four main cables snapped, transferring the load onto the remaining cables and so making them more likely to fail. The observatory has also suffered hurricane and earthquake damage in recent years.
Yesterday, the National Science Foundation – one of the organizations that manages the observatory together with the University of Central Florida (UCF), Universidad Ana G Méndez and Yang Enterprises – announced that the damaged areas could not be stabilized safely.
Safety a priority
“NSF prioritizes the safety of workers, Arecibo Observatory’s staff and visitors, which makes this decision necessary, although unfortunate,” NSF director Sethuraman Panchanathan said in a statement.
Second cable failure puts iconic Arecibo Observatory at risk of collapse
Ralph Gaume, director of NSF’s Division of Astronomical Sciences, adds, “Leadership at Arecibo Observatory and UCF did a commendable job addressing this situation, acting quickly and pursuing every possible option to save this incredible instrument”. “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.”
Astronomers and members of the public have been sharing their thoughts on the closure using the Twitter hashtag #WhatAreciboMeansToMe. The Planetary Society posted, “We are sad to say goodbye to Arecibo but we’re grateful for its phenomenal contributions to space science and planetary defence,” referring to the observatory’s role in tracking near-Earth asteroids.
Many people have been highlighting Arecibo’s role in the 1997 film adaptation of Carl Sagan’s novel Contact, which is about humanity’s first contact with an extra-terrestrial civilization. Others have referred to the 1974 “Arecibo message” – an interstellar radio signal carrying basic information about humanity that was sent from a radar transmitter at the observatory to the globular star cluster M13.
Some have posted personal messages on Twitter, including the educator, physicist and former astronomer Emily Alicea-Muñoz who got married at the telescope and shared some of her wedding photographs (see below).
#Arecibo has always meant so much to me, growing up as an astronomy-obsessed little kid in PR. As an undergrad I got to attend an observing session which was beyond cool. 10yrs ago I married @AstroAhura at the observatory. The decommissioning is so sad 😭#WhatAreciboMeansToMe pic.twitter.com/g4JlYq3tk0
— Emily Alicea-Muñoz, PhD (@drealiceam) November 19, 2020