The Arecibo telescope tracked dangerous asteroids, broadcast to potential aliens, and starred in a Bond film. Here's what the world lost when it collapsed.

Morgan McFall-JohnsenDec 2, 2020, 19:55 IST

The Arecibo Observatory in Puerto Rico as seen before its collapse.NAIC Arecibo Observatory/NSF

The Arecibo Telescope collapsed on Tuesday: Its 900-ton hanging platform crashed into its main dish.
The disaster ended 57 years of historic radio astronomy. Arecibo tracked potentially hazardous asteroids, discovered the first exoplanet, and broadcast a message for aliens.
The telescope even starred in a James Bond film and the movie "Contact."

One of the world's largest and most iconic radio telescopes collapsed on Tuesday.

In its 57 years, the Arecibo Observatory in Puerto Rico revolutionized radio astronomy. It beamed messages to potential aliens, tracked asteroids that could crash into Earth, and discovered the first exoplanet.

It also weathered hurricanes and earthquakes for years. But after Tropical Storm Isaias passed over the island this summer, the cables holding the telescope's receiver platform above its reflector dish began to fail. Shortly after, the National Science Foundation, which owns the telescope, declared that it was too unstable to safely repair. The plan was to try to disassemble it, but then the 900-ton platform broke loose and crashed into the 1,000-foot disk below.

"When I learned of the news, I was totally devastated," Abel Mendez, the director of the Planetary Habitability Laboratory at the University of Puerto Rico at Arecibo, told Business Insider when the telescope was decommissioned last month.

Mendez had been around the observatory since he was 10 years old and worked with it professionally for the past decade.

"It's hard to take. It's like losing someone important in your life," he said. "Yeah, 2020 — it's not good."

Here's what Arecibo accomplished in its lifetime, and what the world has lost with its demise.

Cornell University professor William E. Gordon began designing the Arecibo Observatory in 1958.

William Gordon, who designed the Arecibo Observatory, makes plans with Domingo Albino, the first Puerto Rican engineer to work there, April 1961. Arecibo Observatory

He chose a natural sinkhole in Puerto Rico, where the terrain would fit the telescope's deep, 1,000-foot-wide dish.

The sinkhole where Arecibo was to be built, June 1960. Arecibo Observatory

Construction began in the summer of 1960. Building the world's largest radio telescope was no easy feat.

Workers connect cables under the dish so its panels can be installed, July 1963. Arecibo Observatory

In 1963, the dish was completed with the reflection platform raised above it, supported by 18 cables connected to three towers.

Workers construct a catwalk to the telescope's platform, February 1963. Arecibo Observatory

The telescope started to observe the cosmos. Its first major discovery was that scientists had Mercury's rotation all wrong.

A mosaic portrait of Mercury, taken by the MESSENGER spacecraft on January 14, 2008. NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie

Then in 1974 it detected the first ever binary pulsar: a highly magnetized, compact star orbiting another star. This was a confirmation of Einstein's theory of general relativity.

The blue dot in this image marks the spot of an energetic pulsar — the magnetic, spinning core of star that blew up in a supernova explosion. NASA/JPL-Caltech/SAO

Then in 1974 it detected the first ever binary pulsar: a highly magnetized, compact star orbiting another star. This was a confirmation of Einstein's theory of general relativity.

That same year, Arecibo beamed the most powerful broadcast Earth has ever sent to communicate with potential aliens.

Technician Luis Heredia uses flat shoes to walk on the 20-acre dish of the Arecibo Radio Telescope without damaging the instrument's precise shape. Roger Ressmeyer/Corbis/VCG via Getty Images

Its radar made the first maps of Venus's surface in 1981.

An image of Venus and its thick clouds taken by NASA's Mariner 10 mission during a planetary flyby maneuver in February, 1974. Kevin M. Gill/NASA/JPL-Caletech

In 1992, Arecibo discovered the first known planet beyond our solar system.

Larry Webster and Jill Tarter watch computer screens at the Arecibo Observatory, working on the search for signs of extraterrestrial life, October 10, 1992. Roger Ressmeyer/Corbis/VCG via Getty Images

The telescope made appearances in the 1995 James Bond film "GoldenEye" and the 1997 film "Contact."

Jodi Foster in the film "Contact," based on a novel by Carl Sagan. Francois Duhamel/Sygma via Getty Images

In 1997, the observatory got its Gregorian Dome.

The Gregorian Dome hangs from the receiver platform. Arecibo Observatory

Arecibo identified the world's first repeating fast radio burst — millisecond pulses of radio from beyond our galaxy.

A super-dense neutron star, the remains of a supernova explosion, as captured by three NASA observatories. NASA/JPL-Caltech/ESA/CXC/Univ. of Ariz./Univ. of Szeged

Arecibo's woes began in August, shortly after Tropical Storm Isaias passed over Puerto Rico. An auxiliary cable broke and crashed into the dish below.

A hole in the 1,000-foot-wide reflector dish of the Arecibo Observatory, torn when a cable fell on August 10, 2020. Arecibo Observatory

Three months later, just before engineers were set to begin repairs, a 15,000-pound main cable broke from the same tower and crashed into the dish.

The auxiliary cable that broke on August 10, 2020 was 3 inches thick. Arecibo Observatory

Then assessments engineers warned that if another cable were to break from the same tower, that could send the 900-ton platform plummeting into the dish below. It would bring all three towers with it.

The radio-antenna platform of the Arecibo Observatory in Puerto Rico, as well as three support towers. NAIC Arecibo Observatory/NSF; Business Insider

Then assessments engineers warned that if another cable were to break from the same tower, that could send the 900-ton platform plummeting into the dish below. It would bring all three towers with it.

So the NSF decommissioned the telescope, and engineers set about figuring out how to deconstruct it safely.

An aerial view shows the hole in Arecibo's dish after a second cable failure on November 19, 2020. Ricardo Arduengo/AFP/Getty Images

But before they could make an attempt at taking it apart, the platform collapsed. All 900 tons of it smashed into the disk below, tearing off the tops of the three towers.

The 900-ton platform crashed into the Arecibo telescope's main dish on December 1, 2020. Ricardo Arduengo/AFP/Getty Images

But before they could make an attempt at taking it apart, the platform collapsed. All 900 tons of it smashed into the disk below, tearing off the tops of the three towers.

The loss of Arecibo is a major blow to the world's defenses against hazardous asteroids.

The peanut-shaped 2015 BN590 asteroid, which is shaped like a peanut, is a potentially hazardous object that might one day hit Earth. Arecibo Observatory/NASA/NSF

Arecibo was also the best shot the US had at a comprehensive project to search for radio waves from alien technology.

A starry sky above the observatory. University of Central Florida

The only radio telescope on Earth that can hold a candle to Arecibo is China's Five-hundred-meter Aperture Spherical Radio Telescope (FAST).

The assembly site of China's FAST telescope on July 28, 2015 in Pingtang, China. Feature China/Barcroft Media via Getty Images

Already, astronomers are sharing ideas for building a state-of-the-art facility in Arecibo's place.

An aerial view shows the damage at the Arecibo Observatory after one of the main cables holding the receiver broke in Arecibo, Puerto Rico, on December 1, 2020. Ricardo Arduengo/AFP/Getty Images

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The Arecibo telescope tracked dangerous asteroids, broadcast to potential aliens, and starred in a Bond film. Here's what the world lost when it collapsed.

Cornell University professor William E. Gordon began designing the Arecibo Observatory in 1958.

He chose a natural sinkhole in Puerto Rico, where the terrain would fit the telescope's deep, 1,000-foot-wide dish.

Construction began in the summer of 1960. Building the world's largest radio telescope was no easy feat.

In 1963, the dish was completed with the reflection platform raised above it, supported by 18 cables connected to three towers.

The telescope started to observe the cosmos. Its first major discovery was that scientists had Mercury's rotation all wrong.

Then in 1974 it detected the first ever binary pulsar: a highly magnetized, compact star orbiting another star. This was a confirmation of Einstein's theory of general relativity.

That same year, Arecibo beamed the most powerful broadcast Earth has ever sent to communicate with potential aliens.

Its radar made the first maps of Venus's surface in 1981.

In 1992, Arecibo discovered the first known planet beyond our solar system.

The telescope made appearances in the 1995 James Bond film "GoldenEye" and the 1997 film "Contact."

In 1997, the observatory got its Gregorian Dome.

Arecibo identified the world's first repeating fast radio burst — millisecond pulses of radio from beyond our galaxy.

Arecibo's woes began in August, shortly after Tropical Storm Isaias passed over Puerto Rico. An auxiliary cable broke and crashed into the dish below.

Three months later, just before engineers were set to begin repairs, a 15,000-pound main cable broke from the same tower and crashed into the dish.

Then assessments engineers warned that if another cable were to break from the same tower, that could send the 900-ton platform plummeting into the dish below. It would bring all three towers with it.

So the NSF decommissioned the telescope, and engineers set about figuring out how to deconstruct it safely.

But before they could make an attempt at taking it apart, the platform collapsed. All 900 tons of it smashed into the disk below, tearing off the tops of the three towers.

The loss of Arecibo is a major blow to the world's defenses against hazardous asteroids.

Arecibo was also the best shot the US had at a comprehensive project to search for radio waves from alien technology.

The only radio telescope on Earth that can hold a candle to Arecibo is China's Five-hundred-meter Aperture Spherical Radio Telescope (FAST).

Already, astronomers are sharing ideas for building a state-of-the-art facility in Arecibo's place.