Why Closing the Arecibo Observatory Is a Blow for Science and Imagination
published during a full moon.

Most people go to Puerto Rico for sand and sun. I went there for the radio telescope.

I scored some beach time and enjoyed the 80-degree weather as temperatures back in Boston plummeted so low that schools had to close, but the highlight of the trip was standing on a platform overlooking the world’s largest radio telescope and realizing that I was as close to extraterrestrial life as I’d ever get. That memory is particularly bittersweet given the likelihood that the observatory will soon be shut down due to lack of funding.

Arecibo Observatory

The drive from San Juan to the Arecibo Observatory is appropriately dramatic. A straight shot west on Highway 22 to Arecibo took about an hour, and then we turned south into the Karst region, meandering along dicey stretches that were more path than road, doubling back a few times when it seemed impossible that an observatory with a 1,000-foot telescope was anywhere nearby. But we soon found a paved road and a sign, which we followed to the observatory, and to the massive telescope nestled in a sinkhole.

Popular with tourists (an estimated 100,000 visit each year), students, and researchers from around the world, the observatory museum is full of information about SETI (the Search for Extra Terrestrial Intelligence), the various movies shot there—Carl Sagan’s Contact and the Bond movie GoldenEye are the best known—and the telescope itself. As a space nerd, I couldn’t have been happier. Even though I’ve been to my fair share of science museums and planetariums, I’ve never been to one as comprehensively devoted to studying the cosmos, nor have I felt the same pleasant disorientation; I wouldn’t have guessed I was in Puerto Rico, or even on Earth. The museum imbues visitors with the “cosmic perspective”—being granted a glimpse of the infinite universe gave me what Carl Sagan describes as “that soaring feeling, that sense of elation and humility combined.” And all of this was before I saw the telescope up close.

Arecibo Observatory

Arecibo radio telescope. Credit: Jeff Hitchcock

Until China finished its Aperture Spherical Radio Telescope last year, the Arecibo radio telescope was the largest and most sensitive radio in the world. Instead of capturing light to make faraway objects visible, the massive telescope, which is 1000 feet across, 167 feet deep, and spans roughly 20 acres, receives radio waves via a large dish. Astronomers can examine the frequency and timing of those emissions, including radiation from pulsars and quasars. Constructed between 1960-1963, the Arecibo Observatory was initially conceived by a Cornell University professor as a way of studying the Ionosphere, but since its unveiling, it has been upgraded with LIDAR (a Light Detection and Ranging remote sensing technique) and ALFA (Adaptive optics with a Laser For Astronomy), and has been used for a wide range of scientific projects.

Here’s a brief summary of the Arecibo telescope’s highlight reel:  It helped astronomers figure out that it takes Mercury 59 earth days to rotate. In 1974, two astronomers used it to observe the first pulsar in a binary system (pulsars orbiting one another), a discovery that supports Einstein’s theory of general relativity and led to a Nobel Prize. In the early 1990s, the telescope became the first instrument to detect exoplanets. In 1998, the telescope helped find the SOHO spacecraft, which had lost communication with ESA and NASA. It detected what is now widely believed to be hydrocarbon lakes on Titan, and it has identified hundreds of asteroids both near and far from Earth.

Looking at the massive telescope made me surprisingly emotional.

Perhaps the most intriguing endeavor undertaken by the telescope is its 1974 broadcast of the Arecibo Message to the 11.65 billion-year-old M13 star cluster 25,000 light years away in the hopes of reaching extraterrestrial life.  The are also referred to as the “Great Hercules Cluster,” contains more than 300,000 stars and who knows how many planets. The message, composed by astronomers such as Frank Drake and Carl Sagan, contains basic information about humankind, such as numbers; an atomic, formulaic, and graphic breakdown of DNA; and images of humans, the solar system, and the radio telescope itself. It will take roughly 25,000 years for the message to reach M13—and just as long for any life form to send a response—so we’ll have to wait a long, long time in the unlikely event it initiates an interstellar conversation. Regardless of the response, that the telescope could even send such a dispatch demonstrates its technological and symbolic power. That message was intended to stoke our imaginations, to provoke us into wondering or what else is out there, and what we might communicate if we ever find proof of alien life.

In that respect, the Arecibo Message is reminiscent of the plot of Contact, although in that story aliens contact humans after they pick up Nazi Germany’s television broadcast of the 1936 Berlin Olympics. Few of us think about the chance that extraterrestrial life might receive our TV or radio signals, yet those transmissions are traveling, quietly, in the background as you read this article or go about your day. The Arecibo Message will continue its journey throughout and beyond your lifetime and mine. Just as the humans in Contact had no idea that their broadcast was being received, we won’t know either, which means it’s possible that we’re on the way to initiating our first communication with alien life.

Maintaining the telescope costs $12 million per year, $4 million of which comes from NASA and $8 of which comes from the U.S. Nation Science Foundation, which can no longer maintain that amount of funding because of new projects. Perhaps the most compelling justification for the expense is that the Arecibo telescope comprises a main line of defense—identification—against incoming asteroids; it’s hard to put a price on something that could potentially save the human race. Even though the Arecibo telescope contributes tangibly to science in this and other ways, its ability to send and receive transmissions that make contact with alien life represents immeasurable symbolic importance that may someday become life-changing practical importance.

Such an effort is tantamount to searching for a needle in a haystack. Pouring resources into a radio telescope on the chance that someday it will pick up (or successfully deliver) an extraterrestrial signal is kind of like me liquidating all of my savings to buy a pricey piece of land in the hopes that I’ll find a gold mine on it. Perhaps I’m overly idealistic or romantic when it comes to space missions, but our hope of finding an intelligent life form, as well as our willingness to keep our eyes and ears open to look and listen for it feels every bit as important as the other functions the telescope carries out.

Arecibo Observatory

Aerial view of Arecibo radio telescope.

Searching for intelligent extraterrestrial life has been an occupation, and a preoccupation, for many of us. Back in 1896, Nikola Tesla imagined that his wireless transmission system could be upgraded to beam information to Martians; three years later, he mistakenly thought he received signals from Mars. SETI ramped up in the 60s in both America and the USSR, and since then we have received a handful of signals that we thought, at least momentarily, could be from aliens. The SETI Institute was founded in 1984, and the first screensaver I ever had was SETI@home, a volunteer computing effort in which people’s personal computers scanned for possible transmissions in data gathered by—you guessed it—the Arecibo radio telescope.

Looking at the massive telescope made me surprisingly emotional. Carl Sagan’s words, “we humans are capable of greatness,” rang in my ears. Humans made that dish and schlepped all of its parts through the karsts of Puerto Rico. It made me think of the signaling device Elliot and E.T. make in the woods with a Speak ‘n Spell, record player, fork, hanger, saw blade, and umbrella. While the Arecibo telescope is far more impressive and powerful, it manages to evoke the same spirit of ingenuity and childlike wonder I felt when I watched E.T. and realized that aliens could be out there, if not in our backyards, then in our greater cosmic neighborhood. We should keep looking and listening for them with the scientific equivalent of Reese’s Pieces at the ready.