December 2020 – WinStars 3

Arecibo: the end of a giant

Following two cable breaks last August and November, Arecibo’s radio telescope was in danger and threatened by collapse. The rupture of a third cable finally caused the 900-tonne central platform to fall onto the 305-metre dish.

Arecibo radio telescope

This radio telescope managed by the National Science Foundation, a US government agency, was built in Arecibo on the north coast of the Caribbean island of Puerto Rico. Originally designed to study the ionosphere, it was also an excellent astronomical instrument and the source of many scientific discoveries. On 7 April 1964, shortly after its inauguration, Gordon Pettengill’s team used it to measure the rotation period of Mercury. In August 1989, the observatory was able to capture the image of an asteroid – (4769) Castalia – for the first time in history. The following year, the Polish astronomer Aleksander Wolszczan discovered the PSR pulsar B1257+12, followed in 1992 by its two orbiting planets.

Arecibo was also the data source of the SETI@home project proposed by the Space Science Laboratory of the University of Berkeley. This distributed computing project using computers connected to Internet had two objectives. The first was to prove the effectiveness of this method, which is much less expensive than using supercomputers. The second was to analyse the signals coming from Arecibo’s antenna in order to detect, which was a failure, the existence of non-terrestrial intelligence.


It was possible to extract the metadata from the Seti@Home calculation blocks in WinStars versions 1 & 2 and know the celestial coordinates and the frequency that had been used to make the recording from the radio telescope. Version 3 no longer offered this functionality since the project was discontinued in March 2020.

Arecibo was also a filming location. We will remember for example the scene where Jodie Foster discovers for the first time the radio telescope on which she is about to work (Contact by Robert Zemeckis – 1997).