The Arecibo Observatory. Photo: JidoBG/Wikimedia Commons, CC BY-SA 4.0.
New Delhi: The Arecibo Observatory in Puerto Rico symbolises the first concerted strides by the US to explore the presence of extraterrestrial life. A figure unto itself when it comes to radio astronomy, radar astronomy and atmospheric science, this observatory has appeared on film, in video games and whose Twitter account counts more than 13,600 followers.
In 1974, a group of astronomers used the observatory to beam a signal containing information about Earth and its humans in the direction of the M13 globular star cluster.
So naturally, when two successive architectural failures led to the damage of 250 of its 38,778 aluminium panels, scientists and space enthusiasts have become worried. The New York Times even called it a “rip in the fabric of interstellar dreams”.
Arecibo is one of the world’s largest single-dish radio telescopes. It was set up in 1963 and has weathered several hurricanes and earthquakes in its 50 years of operation.
Its 305-metre wide dish is supported by enormous cables, most of which are aged, according to Associated Press. Five-hundred metres above the dish is a suspended dome that acts as a platform (see image above). This dome-platform is in turn suspended from three towers with the help of 18 thick steel cables attached to three concrete towers.
In August, one of these cables slipped and fell onto the dish below. This forced a nearly 30-metre “gash” on the dish and ripped off its reflective panels, National Geographic reported. Though this was significant damage, it had not particularly worried the observatory’s managers as the cable that had collapsed was an auxiliary one.
However, each tower has four primary cables (and auxiliary ones) to keep this dome-platform suspended. And on November 6, one of the four primary cables broke. This cable should have been capable of holding 544 tonnes but “snapped under only” 283 tonnes, per Associated Press.
A punto de colapsar el Observatorio de Arecibo.
— Pedro Martínez (@pmartinezvelez) November 14, 2020
The tower is now down to three of its primary cables.
The observatory was built so that only two of these cables could keep the dome-platform aloft. But the fact that the cables are old has become a cause for significant anxiety.
The observatory helps nearly 250 scientists with their astronomical observations, on questions ranging from the path of asteroids to whether Mars is habitable. National Geographic added that scientists also “use the telescope to study powerful blasts of energy called fast radio bursts and to spy ripples in the fabric of space-time produced by colliding galaxies.”
The University of Central Florida (UCF), which manages the observatory under a cooperative agreement with the Universidad Ana G. Méndez in San Juan and an engineering firm called Yang Enterprises Inc. for the US National Science Foundation, has been working to secure the structure. In a press release, UCF blamed the cables’ gradual degradation for the structure’s current predicament.
The salty, tropical air of Puerto Rico could well have exposed the structure to salt fog, a lethal corrosive, engineer Dennis Egan was quoted as saying by National Geographic.
“Each of the structure’s remaining cables is now supporting more weight than before, increasing the likelihood of another cable failure, which would likely result in the collapse of the entire structure,” UCF stated in the release.
Several other reports have quoted scientists whose work has already been impacted and stands to be further affected if the observatory stops functioning.
For example, Polish astronomer Alex Wolszczan, who helped discover the first extrasolar planets and pulsar planets with the help of Arecibo Observatory, said, “Losing it would be a really huge blow to what I think is a very important science.”