The death of Arecibo

In 2007, I saw the Arecibo Observatory for the first and last time.

I was in Puerto Rico on a family vacation, and despite a packed schedule, I had to carve out time to see it. The town of Arecibo is a considerable drive from San Juan, where I was staying, and the observatory itself is farther than that. To reach it, you have to traverse a narrow, bumpy dirt road that winds through the dense tropical forests and small homesteads of Puerto Rico’s rural backcountry.

But the trip proved worth it when I laid eyes on that immense, iconic dish, built into a giant natural depression in the landscape. As I said at the time, it must be how Muslims on pilgrimage feel when the Kaaba draws into sight.

Standing on the viewing platform overlooking the telescope, I was overawed by the sheer scale of it. The dish was a vast metal bowl, more resembling a natural formation like a mountain or a river than something humans seemed capable of building. The receiver, which hung suspended from a web of cables, was the size of a house, and the three towers that anchored the cables were large as skyscrapers in their own right. It was like a hand of humanity, reaching out into the cosmos. Being there is still one of the peak experiences of my life.

The Arecibo telescope was one of the 116 images we sent into the cosmos on the Voyager Golden Record, one of a handful of pictures deemed as representative of what humanity has achieved. It was the largest single-aperture telescope in the world from 1963 until China’s FAST observatory, built along similar lines, surpassed it in 2016.

I’ve always liked cathedrals and massive, ornate churches—not for their religious message, but out of aesthetic appreciation for the craftsmanship that went into them. Although they were built at the behest of a faith I don’t share, they were intended to be the most magnificent objects that humans are capable of creating. They skillfully evoke awe and wonder, the sensation of being in the presence of something greater and more significant than your individual self.

For me, giant observatories like Arecibo summon the same emotions, but with an extra layer: a feeling of gratitude and admiration for the designers and the builders who devoted so much effort to the cause of pure science.

I can appreciate the art and skill that went into cathedrals, but it’s always blended with the disquieting knowledge that the beliefs which built them have justified oceans of bloodshed, cruelty and intolerance. When contemplating a great instrument of science, I can feel reverence without that inner conflict.

At its best, science abjures dogma; it transcends national borders and restrictive ideologies. It’s rooted not in hostile claims to absolute certainty, but a humble spirit of curiosity. It’s a peaceful quest to understand the universe, expecting to gain nothing but knowledge, which the discoverers will freely share for the collective benefit of humanity. The Arecibo Observatory and others like it embody these qualities. They’re proof, on a colossal scale, of the best traits we possess.

(Admittedly, a footnote is needed here: The Arecibo telescope was built partially for military purposes, as an early-warning system for detecting ballistic missiles. But pure science was always part of the aim, and soon afterward, it became the sole aim.)

Over its decades of operation, Arecibo produced a bountiful record of scientific discovery. We used it to discover the first solid evidence for neutron stars, the first binary pulsar and the first extrasolar planets. We made detailed radar maps of the Moon and Venus and cataloged near-Earth asteroids. We used it to study repeating fast radio bursts, a mysterious cosmic phenomenon that may arise from the maw of supermassive black holes. Arecibo even sent humanity’s first deliberate message to extraterrestrials, if any happen to be listening.

Sadly, nothing made by human hands lasts forever. A stone pyramid, all but immune to the elements, can endure for millennia. A cathedral can stand for centuries, barring fire, earthquake, or other disaster. But a precision scientific instrument like Arecibo necessarily has a limited lifespan.

In November 2020, thirteen years after my visit, one of the steel cables that held up the instrument platform snapped. After fifty years of exposure to the hot tropical environment, plus the battering of multiple hurricanes, it had weakened to the point of failure. Because there was no way to be sure how much damage the other cables had sustained, the National Science Foundation decided that the telescope couldn’t be repaired safely and would have to be shut down.

That turned out to be a wise precaution. Just two weeks later, the remaining cables of that tower gave way. The 900-ton instrument platform sheared loose, fell, and crashed catastrophically into the main dish. The telescope was utterly destroyed, although thankfully, no one was hurt.

I do mourn Arecibo. Over and above the loss to science, it was an iconic symbol that we lost—one of only a few in our culture that had that level of recognition. I wish it had survived so that more people would have had the chance to see it as I did.

The site may not be destined to languish in ruin until the jungle swallows it up. There have been calls to build a next-generation telescope at Arecibo, more advanced and more capable. However, where the money will come from is an open question. The original telescope suffered from chronic underfunding, even though its operating costs were a drop in the bucket compared to the federal budget. This is partly because Puerto Rico lacks voting representatives in Congress who can fight for its interests—another gap in America’s undemocratic system.

Even as a new generation of space telescopes eclipses the pioneering discoveries of land-based tools, I hope that Arecibo will be reborn. I hope that, one day, there will once again be a shining dish amidst the jungle, sweeping the night sky like a silk line cast into the ocean. And I hope there will be another viewing platform where parents and their children can stand and contemplate the majesty of the universe and our audacious effort to understand it all.