by Marc Kaufman
“Start observations,” Narusawa finally declared. He was speaking, of course, to the assembled journalists (and for that last order he was actually speaking in Japanese). The other astronomers couldn’t see or hear him, but on their own knew the big moment had arrived. Thirty monitoring points began to simultaneously look at and listen to the exact same spot in space, hoping to detect some signal—a burst of light, a radio signal—that could only be made by intelligent life. They would all continue for two full nights, weather and clouds permitting.
Scanning for extraterrestrial communication is for the very patient and the very determined—the sazanka of astronomers. Narusawa would not have any results for months, and ultimately they would not find any sign of ET life. Millions of similar hours have been spent by SETI scientists and advocates around the world—most of them in the United States—and so far no radio blip or laser burst has been confirmed. Nonetheless, SETI observations have been spreading around the world. South Korea, Italy, Argentina, and Australia also have operating SETI programs, and American institutions including Harvard and Princeton have geared up substantially as well, along with the now-flourishing SETI Institute in California.
There’s a simple reason for this, and it has nothing to do with any perceived breakthrough on the horizon, although the technology to hear or see communications from distant planets is in fact advancing and expanding rapidly. It’s rather a function of the near certainty that no intelligent life exists in our solar system except on Earth. There may well be microbial, bacterial life to be found on Mars, Europa, Enceladus or Titan, a second genesis that would strongly suggest life, even complex life, in the universe is a commonplace. But if the explorations of the modern space age have shown anything for sure, it’s that conditions for the evolution of what we understand to be intelligent life do not exist elsewhere in the solar system. The planets and moons are either too hot, too cold, too dry, or made up primarily of gas.
So if scientists are ever going to make contact with the intelligent life many of them are convinced is out there, it will have to happen via interstellar communication, since earthlings are not going to reach the warp speeds necessary to reach other galaxies anytime soon. The nearest star to our own is Alpha Centauri at 4.3 light-years away, and the nearest one with an identified terrestrial exoplanet is Gliese 581, at about 20 light-years away. That’s about 704,952,200,808,876 miles.
This may seem like an enormous, almost certainly impossible wall to climb. But for astronomers familiar with the vastness of the universe, the minuscule size of our own world, solar system and even Milky Way galaxy, the improbability lies elsewhere. To them, it defies scientific logic to think there isn’t other intelligent life out there. So for Shin-ya Narusawa and scores of others around the world, the vanishingly small chance of detecting and confirming a signal from a distant civilization is science at its most exciting—it’s a wide-open field, it’s challenging on many technical levels, it remains unconventional and even controversial, and it holds the promise, however faint, of someday making what would be the biggest scientific discovery of all time. Substantially larger telescopes are being planned and constructed and the logic of Moore’s law, which says the speed of top-notch computers will double every eighteen months or so, offers hope for a much faster and better read of the mountains of data produced by the science instruments attached to those telescopes.
SETI, or in this case OSETI for its optical version, makes additional sense in Japan because of the way telescopes are perceived and paid for. Narusawa’s Nishi-Harima observatory is the center of a large, hilly park that includes ball fields, hiking trails, and guesthouses, and was funded largely by the Hyogo prefecture. Astronomy is certainly science, but it’s also part of “culture and recreation” as far as Japanese policy makers are concerned. The instruments, including the $40 million Nayuta telescope, always reserve time for local people to come in and look at the nighttime sky. “In Japan, our telescopes are all open to the regular people, and when they come in we want to know what are their big interests in astronomy. The top two are these: Is there an end, a border, to the universe? And is there life, especially intelligent life, anywhere other than Earth? So OSETI is what people want.” Narusawa said his goal, his dream, was conducting observations with SETI programs in the United States. And not quite a year later, after Narusawa had presented his Sazanka data at a large, annual astrobiology meeting in Texas, SETI officials agreed to joint American-Japanese observations. Those soon grew to include observatories from thirteen nations on five continents, and a “Project Dorothy” global SETI took place in late 2010, with Nishi-Harima as headquarters. Narusawa was beside himself.
The United States is where SETI was born and where it now—despite decades of skepticism—flourishes. The Japanese team showed impressive coordination, technology, and determination, but they were pretty much groping in the dark. That’s a higher-tech but nonetheless similar place to where SETI pioneer Frank Drake was in 1960 when he first aimed the newly inaugurated antenna of the National Radio Astronomy Observatory in Green Bank, West Virginia, at two relatively nearby star systems, and set about listening for messages. His project Ozma (named after Princess Ozma of Oz) lasted but two months and ended without any contact. But that hardly mattered; a dream was born.
Almost a half century after Drake began his work, the conceptual and technological offspring of Ozma in America are busy listening for that same fleeting signal. Laid out across a high valley between California’s 14,000-foot Mount Shasta and 10,000-foot Mount Lassen, forty-two radio dishes with enclosed antennas stand sentinel and collect data in a systematic way hardly imaginable when SETI began. (This is quite literally true: Drake says the array now works at a level of effectiveness something like 100 trillion times greater than what he had in Green Bank.) A late fall snowstorm was moving into the Hat Creek area when I arrived, and the radio dishes were groaning and grinding in the wind—a perfect Earthly backdrop for an otherworldly venture. But until the winds reach a sustained 30 miles per hour they continue their job—a sometimes targeted, sometimes full-sky, systematic, and nonstop effort to hear radio communications from afar. The telescopes in operation, the biggest radio telescope array in the world, increase by a factor of at least 100 the ability of SETI searchers to find the kind of “transient” radio signals they’re looking for in the sky. But it’s what SETI hopes is only a beginning. Plans for an enlarged Allen Telescope Array at the Hat Creek Radio Observatory call for 350 radio antennas and ever-faster computing power, a concentration of dishes and Moore’s law upgrades that will increase the ability to detect and make sense of radio signals by a factor of 1,000.
The array is set in a leveled field surrounded by lava beds, red fir, and snowcapped mountains, and redolent with the sweet smell of sage even as the snow was falling. Most of the near neighbors walk on four legs. The area, and especially Shasta, looms large in many New Age spiritual tales, and has been considered a sacred spot to native inhabitants going back many centuries. The area has also long been known for reports of Sasquatch or Bigfoot sightings—all part of a worldview the SETI folks are careful to keep far removed from their endeavor. Most of the actual data monitoring and analysis is done far from the field, where astronomers (and their graduate students) receive the data coming into Hat Creek via computer and do their work.
It was only when the strong gusts calmed a bit that I could tell that the wind had camouflaged the sound of the programmed, periodic movements of the twenty-foot-diameter dishes. With a choreography both graceful and surreal—elephants dancing ballet—they moved in pairs or groups to aim at a different star or whole other galaxy. This morning’s mission was to focus on 100 of the 500-plus extrasolar planets discovered in the past fifteen years. It would be the first SETI endeavor of its kind, but followed the logic that animates astronomy (and much of science). A discovery rearranges the scientific furniture, and then researchers in related fields start using the new reality for their own purposes.
Th
e wind was picking up and gusting hard again as I came across one of the numerous antennas named for accomplished donors. This one was named jointly after Jack Welch—not the former chairman of General Electric and business seer, but the famous radio astronomer—and his wife, Jill Tarter. It was a serendipitous but appropriate introduction to the story of how this unlikely, faraway field in the Lassen National Forest came to host 42 radio antennas and may someday have 300 more—all of which would be listening for messages and signals that alien civilizations just might be sending our way.
Jill Tarter, as all SETI enthusiasts know, is a founder, and now the matriarch, of the SETI Institute. A passionate visionary of extraterrestrial intelligence, she became a rather high-profile cultural figure after release of the 1997 movie Contact, which was based in part on her life. (Jodie Foster played her in the movie, which regrettably did justice neither to the subject nor to the individual, although Tarter says it worked miracles in terms of fund-raising.) An engineer and astrophysicist by training, Tarter has an endowed chair at the SETI Institute, located in the high-end Silicon Valley town of Mountain View, and just across Route 101 from NASA’s Ames Research Center, which once was involved in SETI work as well. Jack Welch may not be quite as well-known in popular culture, but in the world of astronomy he is a giant, too: the first to find water vapor and organic formaldehyde in distant space, discoveries that rewrote the textbooks about the makeup of interstellar space. He led the radio astronomy lab at the University of California, Berkeley, for twenty-four years, and since 1998 has had an endowed chair as well, the Watson and Marilyn Alberts Chair in the Search for Extraterrestrial Intelligence, in the astronomy department at Berkeley. It was the first such chair, and remains the only one of its kind. Given their highly specialized skills and unusual interests, Tarter and Welch were destined to meet. They not only met but they both eventually divorced and re-married.
Each is a forceful personality on his or her own; together they are a power duo that can make things happen. In the late 1990s, SETI and Berkeley formed a partnership to build the array, and in 2004 construction began at Hat Creek, thanks to an initial $11.5 million donation from Microsoft cofounder and billionaire Paul G. Allen. Pleased by what he saw, Allen later put in another $13.6 million, and the initial forty-two-dish array was dedicated and began work in 2007. While the telescopes would fulfill the decades-old SETI dream of having cutting-edge equipment that was dedicated to its goals, it would simultaneously provide equally cutting-edge technology for the Berkeley radio telescope program, which researches more traditional and incrementally revealed subjects such as how galaxies form, the nature and properties of dark matter (ubiquitous in the universe but known only by its gravitational pull), and the nature and workings of black holes. Under Welch’s leadership, the array is also drawing a cosmological map of the presence of hydrogen in the universe.
Hat Creek represents quite a coming of age for SETI, which long struggled for telescope time, funds, and respectability from the federal government, and ultimately secured none in substantial or dependable form. The giggle factor was just too high. During the 1970s and ’80s SETI was funded to a limited extent by NASA, and in the early 1990s was finally embraced and awarded funds for a more sophisticated program. But that dream ended quickly in 1993 after Senator Richard Bryan, Democrat of Nevada, made zeroing out SETI into a personal priority. “The Great Martian Chase may finally come to an end,” he said as he closed in on his goal. “As of today millions have been spent and we have yet to bag a single little green fellow. Not a single Martian has said take me to your leader, and not a single flying saucer has applied for FAA approval.”
The odds remain long that Hat Creek and other SETI efforts will make contact with distant civilizations, but what the scientists are doing is far from the caricature presented by the senator from Nevada. The former senator would be dismayed to know that not only has SETI attracted millions from savvy high-tech entrepreneurs and scientists, but the Institute is again eligible to compete for NASA funds after its program was deemed to be scientifically sophisticated and sound. The forty-two dishes are unusual not only because of their SETI mission, but because they’re also a cutting-edge design and generally seen as the future of radio astronomy.
The United States already has one huge radio astronomy dish at Arecibo, Puerto Rico, which is a thousand feet across and can pick up radio signals from 100 million light-years away. For years it was the primary site for SETI work, though listening time was limited. A much-used “giant eye” with real star power—it has served, after all, as a backdrop to movies ranging from Contact to the James Bond film GoldenEye and an X-Files episode called “Little Green Men”—it nonetheless belongs to the past and is struggling to hold on to the limited National Science Foundation funding that it receives. Not only would it be prohibitively expensive now to build an Arecibo, but it would be seriously behind the technological curve. Welch in particular pioneered the notion that many smaller dishes hooked up together would have the same power and sensitivity as a big dish, and would do it at a much lower cost. Hat Creek is the prime example of that change in approach and vision, and its receiving dish is actually as large as the distance between the most distant antennas. At 350 antennas, the Hat Creek dish would be, in effect, a kilometer in diameter.
Space technology aside, Hat Creek also gives the SETI enterprise a permanent and easily expandable home. Over the next two dozen years, the Allen Telescope Array as currently configured will gather a thousand times more information from distant star systems than has been collected in the past forty-five years. The data will also be far more precise and will come from fainter, more distant stars. Perhaps most important, the dishes produce a detailed image of a broad expanse of the radio sky at any given moment. This is how Seth Shostak, SETI’s lead astronomer, put it: “Let’s say you’re looking for elephants in Africa. If you have one guy with binoculars, your chances of seeing a tusker are pretty limited and it will take a long time to succeed. Compare that with having one thousand guys with binoculars looking for elephants. Suddenly, you’ll be finding a lot of elephants.”
The Hat Creek radio waves are collected, bundled, and carried to waiting computers that split them into four categories based on their radio frequency. Generally, two of the bundles go to SETI and two to Berkeley, a sharing that made the Allen Array so appealing in the first place. SETI needed the solidity of the Berkeley lab to be credible when it approached potential donors, and Berkeley needed the sexiness of SETI. With both Jill Tarter and Jack Welch convinced it should go up at Hat Creek, the momentum was hard to stop.
The antennas are designed and programmed to pick up distant radio waves (a relatively low-energy form of radiation) at a frequency between 1,420 megahertz and 1,660 megahertz. That’s a region of the radio end of the electromagnetic spectrum that has less competing background “noise” from the universe than most others and, as a result, more radio waves, and more distant radio waves, can be detected. In radio astronomy and SETI parlance, that range is called the “Cosmic Water Hole,” because it exists between the points on the spectrum where radio waves from interstellar hydrogen (H) and interstellar hydroxyl ions (OH) arrive on Earth. It was Bernard “Barney” Oliver, a top engineering executive at the Hewlett-Packard Company, the early head of the NASA SETI program and later the first president of the SETI Institute, who gave the “water hole” its name. The logic was simple: The spectral region between H and OH was relatively tranquil and quiet, rather like water (H2O), and the relative calm seemed obviously to be a function of the breaking apart of interstellar H2O. Oliver proposed that any advanced civilization would be able to similarly identify the “water hole” as a good frequency for communications, and the scientific-extraterrestrial community agreed. “Where shall we meet our neighbors?” Oliver famously asked decades ago. “At the water-hole, where species have always gathered.” Many SETI observations are still done at Hat Creek and elsewhere at water-hole frequencies.
As Hat Creek stat
ion scientist Rick Forster explained it, a major reason for choosing Hat Creek as home to the array was that it was especially quiet in the “water hole.” Many other kinds of man-made radio noise now pollute that region of the radio spectrum, and it’s increasingly hard to find places where that new noise doesn’t drown out signals that might be coming from far away. Locations like Hat Creek, the scrub deserts of New Mexico and Arizona, and the high Atacama in Chile are home to the best new radio arrays because—while they still have to account for radio waves coming from cell phones, high-definition television, and military satellites—there is far less radio noise from surrounding human activity than most places.
The SETI Institute is always struggling for money, but the overall enterprise is more capable and stable now than ever before. So, fifty years into SETI, it seems entirely fair to ask this question: Why, if scientists and ET enthusiasts are correct and there are many technologically advanced civilizations in the universe, have we neither heard nor seen any signs of them? Earth would plausibly be the kind of place intelligent extraterrestrials might try to contact, since its atmosphere has been awash in probably the most telling signatures of life—oxygen, ozone, and water—for 2 billion years. For the last hundred years, we’ve also put out an enormous amount of radio traffic that could plausibly be detected from deep space. Yet there have been no incoming messages detected. Some in astrobiology see SETI as the field’s most vulnerable Achilles heel. Too much looking and listening; not enough finding. As a result, the half-century-old SETI policy of relying primarily on radio telescopes to listen for messages is frequently challenged. So, too, is the SETI decision to remain in a listening mode rather than sending out pings and flares from Earth that might inspire a response. SETI scientists say listening offers the greatest chance for success, but increasingly, others disagree.
