The Arecibo Telescope
The Arecibo Telescope was the main instrument at the Arecibo observatory in Puerto Rico.
It was a non-movable 305m spherical reflector dish built into a natural sinkhole, with a cable-mount steerable receiver 150m above the dish. There were also several radar transmitters for emitting signals mounted on the receiver.
Completed in 1963, it was the world's largest single-aperture telescope for 53 years, surpassed in July 2016 by a similar 500m receiver in China.
The picture above may seem strangely familiar if
you have seen the James Bond film, Goldeneye.
In the movie the
dish rises out of a
lake (that was CGI)
and Bond and his
female companion
actually slide down
the dish. Much of
the climax of the movie takes place on the gantries
above the dish.
But being a movie set was only part of this telescope’s colourful history. In many old SF stories Mercury is described as having one side always facing the sun; similar to our moon always having the same side facing the Earth. Arecibo was able to show that wasn’t the case.
It was the first instrument to map an asteroid (Vesta). It was also used to study pulsars and to detect potentially dangerous near Earth asteroids.
The late Carl Sagan used its radar transmitters to send an interstellar radio message carrying basic information about humanity and Earth. It was sent to the globular cluster Messier 13 in 1974. It was meant as a demonstration of human technological achievement, rather than a real attempt to enter into a conversation with extraterrestrials.
The spherical section of the receiver above the dish you can see in the photograph was added in the mid 1990’s greatly increasing the platform’s weight and requiring extra cables to be added.
In the following years the telescope survived 2 hurricanes and an earthquake. In August 2020 a cable mysteriously broke damaging the dish. Three months later a second cable broke.
After studies by engineers, it was decided that the telescope could not be safely repaired, and plans were being made about how to safely demolish it. The telescope, however, had its own ideas and suffered a catastrophic collapse on 1st December 2020. Fortunately, no one was seriously injured. The observatory is still open using other instruments, and the destroyed dish is now a tourist attraction.
You can find a spine-chilling video of its collapse
(from 2 different viewpoints) at
