The Arecibo Observatory in Puerto Rico has figured prominently in our coverage of the cosmos here on ExtremeTech, so we’re sad to report that this iconic radio telescope will be demolished. That’s not because of a lack of funding or to clear the way for a new dish. The Arecibo dish was damaged following a series of cable failures, and the National Science Foundation (NSF) has decided it would be too dangerous to repair.
Construction of the observatory began in 1960, and it took three years to get the 1,000-foot (307-meter) spherical reflector up and running. As a radio observatory, the dish’s main job is to bounce faint radio signals up to the receiver, which hangs above the distinctive bowl. By moving the receiver with cables, astronomers can collect data from different parts of the sky. Arecibo also has four radio frequency transmitters maxing out at 20 terawatts of continuous power. Astronomers even used the array the transmit a message to any aliens who might be living in a distant globular cluster in 1974. It’s called the Arecibo Message.
The design of Arecibo has made it a highly adaptable stalwart of space research for decades, but the project took a turn several months ago. On August 10th, an auxiliary cable broke free and fell into the dish, causing major damage. The NSF began investigating repair options along with current Arecibo operators the University of Central Florida and Yang Enterprises, but tragedy struck again on November 6th when a main cable snapped. This cable also fell into the dish to cause even more damage (see above).
An independent engineering assessment has now wrapped up, and the recommendation is not great news. The NSF confirms that repairing the instrument with two failed cables would pose an unacceptable risk to workers. The remaining cables are holding the 900-ton receiving platform 450 feet above the dish, and they’re well past the rated safety tolerances. If another cable snaps, there could be an uncontrolled collapse that sends the platform and all three support towers into the dish. The only course of action is to demolish the dish, ending Arecibo’s 57-year mission.
Decommissioning Arecibo isn’t going to be risk-free, though. There are other facilities around Arecibo that will continue operating after the observatory is gone. For example, there is an ongoing LIDAR research building under Tower 12 set to resume operation when the site is safe again.
There are more radio telescopes around the world than there were when Arecibo was built in the 1960s (like the Five-hundred-meter Aperture Spherical radio Telescope in China), but it’s still a blow to the scientific community. Arecibo was also a part of popular culture with appearances in films such as Contact and Goldeneye, and TV shows such as The X-Files. There are no current plans to rebuild Arecibo, but we’ve got our fingers crossed.
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