In the spring of 1960, a 29-year-old astronomer with streaks of preternaturally white hair and a devil-may-care attitude set out to tackle one of humanity’s most existential questions: Are we alone in the universe?
Frank Drake, then an astronomer at the National Radio Astronomy Observatory, was gearing up to search for radio whispers from faraway civilizations that might be sailing the cosmic sea. For such a grand quest, he had a budget of $2,000 and access to a radio telescope thought to be sensitive enough to detect transmissions from any potentially broadcasting extraterrestrials.
“Searching for intelligent life was considered bad science in those days,” says Drake, who just turned 90 years old—and is better known to me as Dad.
At the time, looking for evidence of alien technologies was still squarely in the camp of schlocky science fiction. But for my dad, it was worth taking a risk to find out if the cosmos is as richly populated as Earth’s teeming oceans—or if humanity is adrift in a profoundly quiet interstellar expanse.
Humble and curious, with a knack for quiet mischief, Dad is committed to his science, still writing research papers and serving on committees. My early memories are full of trips to observatories and conferences, and the singular pleasure of staring through telescopes at the twinkling sky. I was never bitten by the academic astronomy bug, though.
It wasn’t until I began working as a science journalist that I realized just how risky and revolutionary Dad's early work really was.
Astronomers knew of no worlds beyond our solar system back in the 1960s, but Drake reasoned that if planets like Earth orbited stars like the sun, then those worlds might be populated by civilizations advanced enough to broadcast their presence to the cosmos. His logic made sense: For the last century, Earthlings have been making these sorts of announcements all the time in the form of TV and radio broadcasts, military radar, and other communications that leak into space.
So he designed an experiment to search for signals coming from worlds that could be orbiting the nearby stars Epsilon Eridani and Tau Ceti. He named the experiment Project Ozma, after the princess in L. Frank Baum’s Oz series—an homage to an adventure tale populated by exotic and unearthly beings.
Before sunrise on April 8, 1960, Drake climbed an 85-foot radio telescope in Green Bank, West Virginia, jammed himself inside a trash-can-size piece of equipment, and launched humanity’s first scientific search for extraterrestrial intelligence—now known as SETI. For three months the telescope scanned its targets and found nothing more than cosmic static. The stars were stubbornly quiet.
“That was a disappointment,” Dad told me a few years ago. “We’d hoped that, in fact, there were radio-transmitting civilizations around almost every star.”
Even though Ozma failed to find evidence of extraterrestrial technologies, the project was uniquely transformative—the first step toward solving a monumental mystery.
“For me, Ozma is a platform that points out to the world that, when compared to something else that might potentially be out there, we’re all the same,” says the SETI Institute’s Jill Tarter, one of the leading astronomers in the field. “That cosmic perspective is just critical to solving the challenges that we’re looking at.”
Sixty years after Ozma, an endeavor that once sat on the fringe of science is gaining legitimacy. Instead of single experiments staring at a handful of stars, today’s quests for contact are nearing the ability to monitor the entire observable sky for signals, all the time.
Still, the discipline hasn’t completely shed the “giggle factor” that makes funding difficult and has quashed federal support for more ambitious projects, such as NASA’s High Resolution Microwave Survey. Money can be scarce in SETI, the field has relatively few dedicated practitioners, and it has yet to fully infiltrate the halls of academia.
But momentum is gathering. A new crew of astronomers is now leading the SETI vanguard and fighting to secure a path toward answering perhaps life’s most fundamental question.
“To me, life is the most interesting property of the universe—just, full stop,” says Andrew Siemion, one of the leaders of the most sweeping SETI searches to date called Breakthrough Listen. “When I open my eyes and I look around at reality, life is the interesting thing. I just don’t get why more people didn’t want to work on SETI.”
In the wake of Ozma, unlikely allies
Project Ozma attracted a firestorm of media attention. In 1961, the National Academy of Sciences asked Drake to convene a meeting at Green Bank to further discuss the search for intelligent life. While organizing that meeting, he casually came up with the now-famous Drake Equation, a framework for estimating how many civilizations might be detectable in the Milky Way galaxy.
For a turn, it seemed that SETI could thrive, but similar efforts soon sputtered.
“There were radio astronomers all over the place who wanted to do SETI searches, but they got squelched,” Dad says, rattling off a list of locations throughout Europe and in Australia where similar projects mostly failed to gain ground. “It still had this problem of being considered flaky stuff.”
Not, however, in the Soviet Union. On the other side of the Iron Curtain, astronomers had gotten word of Ozma, and they eagerly started scanning stars for signs of life.
“There were far fewer restrictions on what Soviet scientists could do. They had kind of steady budgets because of the way the centralized communist government worked. They could kind of do whatever they wanted,” says science historian Rebecca Charbonneau of the University of Cambridge, who specializes in SETI research during the Cold War era. “Your dad was very jealous—they could do all these searches.”
SETI quickly took off in the U.S.S.R. with astronomer Iosef Shklovskii at the helm, and until the Union’s rupture, Soviets and Americans would meet to exchange ideas about searching for intelligent life. In a way, Charbonneau says, it’s not surprising that the two competing superpowers ended up leading SETI searches during the Cold War. The ongoing space race forced both nations to think about what might exist in the heavens, and nuclear stockpiles forced humanity to consider its future on Earth and among the stars. On top of those nagging existential questions, both nations had a rich history of science fiction rife with ideas about first contact.
But even if the Cold War did drive the two countries to compete for the first detection of extraterrestrial life, the search was a congenial endeavor. Over the years, and despite at least one high-profile false detection, the relationship morphed into friendship and a push for global community.
“Shklovskii ended up publishing what is generally considered one of the first popular books on SETI, coauthored with Carl Sagan,” Charbonneau says. (It’s called Intelligent Life in the Universe.) “There’s this theme of scientists trying to figure out what alien life looks like and how we might communicate with it, and at the same time as they’re trying to communicate with the ‘alien’ on Earth.”
In the United States, however, SETI was struggling. It was once funded by NASA, but Congress cut federal funding for SETI projects multiple times, deriding the search as “Martian hunting” and calling it a veritable waste of taxpayer dollars. Since the mid-1990s the nonprofit SETI Institute, founded in 1984, and the University of California, Berkeley have been among the most active SETI research centers.
But in academia, recruitment to the field is poor. Few students enroll in graduate programs with the intent of searching for life among the stars—except for at Harvard University, where astronomer Paul Horowitz has maintained multiple projects aimed at detecting both radio signals and laser flashes from communicating civilizations. Over the decades, Horowitz has trained four Ph.D. students in SETI—more than anyone else.
“When you catch the SETI bug, it’s hard to shake it off,” Horowitz says. “It’s the greatest experiment you could imagine.”
Eavesdropping on aliens
In 1995, astronomers at last found the first planet orbiting a faraway, sun-like star. The massive Jupiter-like world, called 51 Pegasi b, is completely inhospitable for life as we know it. Since then, however, astronomers have discovered thousands of exoplanets—or planets orbiting other stars—and many have conditions that could be favorable to life.
Six decades after Ozma, we know that planets vastly outnumber stars in the Milky Way, providing billions of places for alien metabolisms to emerge. And on Earth, scientists are finding life in every improbable place they look—from boiling, acidic hot springs to the deepest, darkest, most pressurized parts of the seafloor.
“What we’ve learned about our environment, in an astronomical sense, is just making SETI an inevitable question,” Tarter says. “You're forced by the science that has come over the past decades to take that next step.”
In 2015, a massive new project called Breakthrough Listen kicked off. Funded by Silicon Valley tech investor Yuri Milner, the 10-year, $100-million enterprise harnesses the power of the world’s sharpest radio telescopes to sniff out signs of life among the million nearest stars. Milner—named after Yuri Gagarin, the first person to fly to space—has an abiding curiosity about the cosmos and a quirky set of connections to humanity’s extraterrestrial endeavors that, he thinks, make his involvement in the search almost destiny.
“Somehow, it was all written in the sky somewhere,” Milner says.
Breakthrough Listen is halfway through its tenure and, like Ozma, has yet to hear an alien whisper. But the team, based largely at UC Berkeley, is plunging ahead with observations. Already, the project commands large amounts of time on the 100-meter Green Bank Telescope and at Australia’s Parkes Observatory, and scientists are getting the gear in place for Breakthrough to eavesdrop on observations made by MeerKAT, an array of radio dishes in South Africa.
“I truly believe that this is something we should keep doing,” Milner says. “If we keep doing this for dozens of years, maybe a hundred years, I think we will have an answer one way or another.”
Astronomers are no longer only looking for interstellar radio stations, but for optical pulses, waste heat generated by powerful civilizations, and any other signs of crafty extraterrestrials. Instead of probing for “extraterrestrial intelligence,” the field is shifting to use the term “technosignatures”—coined by Tarter to eliminate ambiguity in defining “intelligence.”
One of these projects, called PANOSETI, is designed to scan the entire sky for fleeting but intense flashes of optical and infrared light. Led by Shelley Wright, an astronomer at the University of California, San Diego (and a former undergraduate advisee of my dad), the project will capture an absolutely astonishing amount of information about transient astronomical phenomena such as supernovae —and, just maybe, artificial transmissions.
“We’re taking a picture of the entire observable sky, every nanosecond,” Wright says. “And we say, hey, was there anything in that field that kind of went bump in the night?”
The future of the search
Today, some say that SETI is in the midst of a renaissance. Large projects are kicking off, funds are materializing, and astronomy courses now include a broader perspective on humanity’s place in the universe.
“We have a whole generation of astronomers for whom, obviously, you should be looking for intelligent life in the universe,” says Jason Wright of Pennsylvania State University, who has worked in recent years to secure a place for SETI in academia. “The way we teach astronomy now is right out of Cosmos,” he says, referring to Carl Sagan’s influential work on cosmic evolution.
If SETI can maintain its current momentum, astronomers are optimistic that future projects could be even more ambitious—maybe even as pie-in-the-sky as installing a radio telescope on the far side of the moon, the only place in the solar system where Earth’s constant transmissions don’t overwhelm radio signals from the cosmos.
Researchers hope that SETI observations will soon be tethered to other observatories, sifting through the multitudes of information that scientists are already collecting about the universe to look for anything out of the ordinary. “I think SETI is going to become a part of the science case for every major observatory in the world, ground-based or space-based,” Siemion says.
The answer to SETI’s most profoundly existential question might arrive in the next few years. Or it could take decades, centuries, or even longer before we know if other civilizations share our galaxy. Detectable radio signals have only been traveling away from Earth for about 100 years, so any civilizations more than 100 light-years from Earth could not have detected us, even if they had the required technology.
Alternatively, we may be the only active civilization at this moment in time. Perhaps others have already risen and fallen in the 13.8-billion-year history of the universe—or they may still be nascent lifeforms, slowly evolving the cellular machinery needed to power complex metabolisms.
Or, perhaps, we are in fact alone—in many ways the most mysterious of possibilities.
In any case, the answer to the question of Project Ozma has the potential to change the course of humanity’s future. Dad says that when he climbed up that telescope 60 years ago, he knew he was doing something different—but he didn’t anticipate how captivating the search would be, or how SETI would grow into the enterprise it is today.
”You went from one or two people doing something about detecting extraterrestrial life to hundreds—including some of the brightest minds on the planet,” Dad says. “I’m very happy about it.”