The mighty Arecibo telescope will be closed forever, the US National Science Foundation has decided.

But the radio telescope which brought us confirmation of the first exoplanet in 1992 will undoubtedly live on in the hearts and minds of scientists, many of who took to social media to mourn the end of an era and to celebrate how Arecibo had changed their lives and inspired their careers.

The iconic radio telescope was the world's largest for decades, and it's weathered a few hurricanes as well as pop-culture fame in its 57 years of beaming out interstellar messages and receiving radio wave signals from space.

Alas, the US National Science Foundation (NSF) has decided that it cannot safely repair the telescope after two surprise cable failures, one in August and another in early November, ripped gigantic holes in Arecibo's 305-metre-wide (1,000 ft) reflector dish.

"For nearly six decades, the Arecibo Observatory has served as a beacon for breakthrough science and what a partnership with a community can look like," NSF Director Sethuraman Panchanathan said in a statement announcing the decision to decommission the telescope.

Scientists are gutted by the news and have been flooding social media with posts under the hashtag #WhatAreciboMeansToMe

"What I love the most about working with Arecibo is how it is a community institution," said astronomer Kevin Ortiz Ceballos from the University of Puerto Rico. "[I]t has broadened Puerto Rican participation in science in immeasurable ways."

The Arecibo Observatory, named after its nearest city on Puerto Rico's northern coast, became a major centre for science education and provided priceless training opportunities for many aspiring Puerto Rican scientists, too.

Among Arecibo's greatest achievements was observing the first set of binary pulsar stars in 1974, a discovery which would pave the way to detecting gravitational waves for the first time, some 40 years later.

It was also the scene of first dates and wedding ceremonies, of Hollywood movie shoots and eye-opening school field trips.

The Arecibo Observatory is part of Puerto Rican culture and gave Puerto Ricans the opportunity to do science in their own backyard, said Kelby D. Palencia-Torres, a physics student at the University of Puerto Rico Mayaguez.

"It's more than an icon, a tool, a structure, it is a community that has been built with no barriers. Connecting people from all over the world … as well inspiring young kids to explore," he said.

Puerto Rican scientist Junellie González Quiles, now a doctoral student at John Hopkins University, recounted how she was inspired to study astronomy after astronomers bearing telescopes from the Arecibo Observatory visited her summer camp.

"It sparked an interest that only grew as years went on, and it was my goal to do research at the Arecibo Observatory when I was older," said González Quiles, who later attended the Arecibo Observatory Space Academy.

"If it hadn't been for this program at the Arecibo Observatory, I would not be where I am today," she said. "I would not be a graduate student. It changed my life."

Evident in the stream of #WhatAreciboMeansToMe posts is that Arecibo not only galvanised generations of planetary scientists, astronomers and astrophysicists; it also inspired leagues of biologists, engineers and instrument scientists, too.

Botanist Amelia Merced said visiting the Arecibo Observatory on a school excursion made her realise she could be a scientist.

"The presence of the largest telescope in this small island, listening to the universe in search of life. Sounded like a dream but it was real," Merced said.

Shark scientist Melissa Cristina Márquez similarly reflected on what Arecibo meant to her as a Puerto Rican who has followed a career in science all the way to Curtin University in Australia.

"It was more than a telescope to me. It was a beacon of hope – that things and people made in #PuertoRico could thrive on the world stage," she said.

"Arecibo showed me that we mattered. I am so, so proud of this telescope and all it represents."

However sad it will be to see the grand Arecibo dismantled, the telescope will surely remain a fixture for the part it played in our search for extraterrestrial life and the hunt for gravitational waves.