by Sarah Scoles
It didn’t make sense, said Dreher. If the signal were actually coming from the star, as the first sequence of tests indicated, it should have dimmed by a small amount in this new test.
By then, it was late afternoon and the star would soon set. Tarter debated calling another observatory, located to the west, where YZ Ceti would still be above the horizon. But other astronomers didn’t like having their observations interrupted—what if they missed some truly exciting blazar blast or neutral-hydrogen action because they had decided to check up on a dubious claim that ET had finally phoned home?
Besides, Tarter didn’t want to shout, or even whisper, about that potential phone call in public yet, not until they were sure. A false announcement could ruin them; crying wolf never helped a struggling cause. That is, after all, the point of the fable.
She had, though, called California, and her colleagues at the SETI Institute were watching a mirror-copy of the Green Bank control room computers that sat in their lobby. Back in West Virginia, when YZ Ceti set, Tarter and Dreher turned the Phoenix controls back to automatically search the next stellar targets rising in the East. They gathered up the log files and printouts from the day’s activities and headed off to dinner, with a growing sense of disappointment that this signal was not the One.
Sometime during the day, the New York Times called Seth Shostak, Tarter’s colleague and a favorite of the media because of his down-to-Earth dad humor. Science journalist William Broad wanted to know about this signal they were tracking down there in West Virginia. How had he heard about it, in those days before social media, when the team had locked themselves in the control room? Broad explained that he was working on a tribute piece for Carl Sagan, that would post on the second anniversary of his passing. He had just called Sagan’s widow, Ann Druyan, who had that morning talked to Tarter’s unflagging administrative assistant, Chris Neller, who for decades kept the institute—and Tarter—running from behind the stage curtain. Neller had told Druyan that Tarter had delayed her homebound flight to “take care of some business” at Green Bank. In SETI, that’s suspicious.
Shostak, according to his book Confessions of an Alien Hunter, told Broad, “Well, we’re continuing to track the star. But, you know, these things often turn out to be man-made interference. We’re checking out a lead on that right now. But I think we’ll know more in three hours or so. Can I call you back then?”
Broad said yes, probably sure he had the scoop on everyone else because of his fortuitous phone call.
By the time YZ Ceti crawled above the horizon at 5 A.M. the next day, Tarter and Dreher’s perusal of the previous day’s data and a bit of Web searching had turned up a mundane match for their signal: the Solar and Heliospheric Observatory (SOHO), a satellite that takes close-ups of the sun that make it look alive and angry. Every star looks like that, with a campfire-coal surface and loops of plasma protruding from its surface. Maybe somewhere else in the Milky Way, another civilization knew how to take such pore-level portraits of their star, too. But the point was, they had found—once again—only evidence of us. Unfortunately, they had forgotten to tell their colleagues back in California about this mundane explanation, and those folks had stayed in their offices late into the night, nervously waiting for YZ Ceti to rise and the search for the signal to begin anew. A significant amount of professional fence-mending was required when Tarter returned.
If the Woodbury telescope had been functioning, if the spacecraft had been orbiting Earth instead of the sun, and if Tarter had not misread the output of a database query she made shortly after the initial discovery, this incident would have resolved itself right away. Instead, they learned a lesson: If they ever did detect a communication from an extraterrestrial civilization, they wouldn’t be able to keep it a secret. The William Broads of the world would find out fast—and this before Twitter.
No more alarms—false or otherwise—rang while Phoenix operated in Green Bank. It traveled next to Arecibo, the jungle where its predecessor, HRMS, had first begun on Columbus Day six years earlier. Harp says that during their long evenings in the jungle, Tarter would turn on samba music and dance around the small area off the main control room, where the Phoenix computers issued controls to the telescope and displayed any signals being tracked. All the Phoenix detection equipment lived in the parking lot just outside, within the MRF trailer carefully pulled up the winding mountain roads in Puerto Rico. But this was a transformed MRF, with the old NASA-derived electronics ripped out and new PC-based processors slipped inside. It sat next to the control room, which is a ship captain’s wall of glass that looks out over the bowl of rock and greenery in which the Arecibo Radio Telescope rests. Astronomers like to jog around the dish, which has a perimeter of more than a half a mile. Under its speckled shadow (holey from the mesh surface), jungle plants grow. Iguanas saunter up to the patio where the astronomers eat lunch. But above the telescope, something new hung like a chandelier.
Called a Gregorian dome, it looks like the Epcot ball with the bottom third cut off. It hangs 500 feet above the dish on an arced track, and scientists can direct it to travel along this track to aim at different parts of the sky. Before that, Arecibo was more limited in what it could point to and detect, and the upgrade made the telescope a better fit for SETI work.
The Gregorian apparatus attaches to a flat circular track, parallel to the ground. Along that track, the arc and Gregorian can twirl like Disney World teacups, allowing even more pointing. Most importantly for Tarter and Project Phoenix, though, the Gregorian contains two more shaped reflectors inside to correct distortion from the primary dish, making it useful for a wide range of frequencies. And that, in fact, is why NASA—preparing for its SETI program, back before Congress banned SETI from NASA—had invested the initial millions into the upgrade years earlier.
That the SETI got time on the telescope at all was a political favor. The cost of the NASA-SETI-funded contribution to the upgrade almost exactly matched the operational cost of the hours of observation the team requested. And although Arecibo is like other large-scale American facilities operated by the National Science Foundation, in that allocation committees rank proposals by merit—a process that doesn’t usually go well for SETI—Tarter suspects the observatory director chose his proposal reviewers “carefully.” SETI became the largest single user for the next 5+ years, taking up 5 percent of the telescope’s total operation time.
A controversy around SETI taking over telescope time comes up in the movie Contact, which Robert Zemeckis began filming around this time. In Contact, Tarter’s arch-nemesis David Drumlin tries to convince Ellie Arroway to stop doing SETI, because of its null results, its needle-in-a haystack-ness, and its lack of contribution to larger science—or even its subtraction from larger science, whose time it steals. Drumlin’s speech doesn’t work.
When fictional Arroway stays at Arecibo, she lives in one of several cabins that scientists do actually occupy when visiting the observatory. Dubbed the visiting scientists’ quarters (or VSQ, because astronomers love acronyms), they sit high on a hill, up seven flights of outdoor wooden stairs away from the control room. Strange slippery molds and algae grow on the stairs, easily landing you in a pile of mud. The cabins have tiny linoleum kitchens connected to living rooms of bamboo furniture with floral, almost three-dimensional cushions. Two rooms with two beds—one of which is meant for you to share with Matthew McConaughey, if Contact is an indication—are nearly open to the elements. The sounds of coqui frogs (which sound like their name) tunnel through the wood walls. From the porch, you can look out over the kinds of lush trees whose oxygen production you can almost feel. The air tastes new.
Tarter has lived in these VSQ for many months total, including during Phoenix. Jodie Foster merely played at doing so during the filming. But when Foster took on the role of Ellie Arroway, she wanted to find out what being an astronomer really was like. For that, she turned to the person on whom Sagan had modeled her character.
Before filming be
gan in 1996, Foster called Tarter regularly to talk. “It was never about the science,” Tarter says. “She was clear that she wasn’t going to teach anyone science, but she wanted to find out what the life of a scientist was like.”
One day, Foster asked, “Do astronomers have egos?”
Tarter, who openly does, laughed. The answer is simple: yes. They’re the surgeons of the physical sciences, godlike because of their cosmic dealings, or like prophets sent to interpret cosmic truths for the masses. Tarter laughed some more, to make sure Foster knew her response was sarcastic. “No,” the radio astronomer said. “Well, maybe the infrared astronomers.”
One day during filming, when both women were doing their respective jobs at the world’s largest telescope, Tarter took Foster up into the Gregorian dome. They rode the jerky cable car up to the support platform and trekked across the catwalk. Tarter never thought about falling, never felt that jolt when she looked down from a great height (instead, she says that the Gregorian platform offers the best views on the island). When they reached the middle, they ducked under the Gregorian’s opening. Inside, the air felt cooler. Tarter looked up at the polygon-panel ceiling and listened to the chirp, chirp, chirp of the cryogenic vacuum pump echoing off the white walls. Right then, the telescope was collecting radio waves from many light-years away. These waves had left their home in outer space years ago. No one could see them, but the telescope’s electronics turned them into pictures and plots that humans can make sense of. This dome let scientists see an invisible universe.
“This is an astronomer’s cathedral,” she said, turning to Foster. Then, switching back to science mode, she said, “It works the same way as the whispering dome at St. Paul’s.”
There, sound waves from human voices slink near the curved wall’s circumference, arriving on the far side of the building nearly as loud as they were when they left. If an intelligent being stood across such a room from you, trying to communicate, you would have no trouble hearing their message, no matter how quietly they spoke. You would just need to be in the right place at the right time, listening.
CHAPTER 9
EXTREMOPHILES AND EXOPLANETS
Today, the SETI Institute’s offices are situated strategically in Mountain View, California, in the ever-expanding heart of Silicon Valley. From here, Tarter and her team have access to the tech world’s best minds and their big money. Until 2015, the institute shared their two-story duplex building with a company called Jasper, which bills itself as “The ON Switch for the Internet of Things.” The building itself is simple, gray. And at the back of the oak-shaded parking lot, a neighborhood-style basketball hoop hangs over prime shady parking spaces. Some guy does tai chi out there every day at lunch.
Tarter’s office sits in the middle of the building, filled with paraphernalia: a director’s chair that says JILL TARTER PRODUCTIONS, 22 different certificates, a model dinosaur skull, three globes, an autographed photo of Jodie Foster, and that screensaver: “So . . . are we alone?” It’s almost as a movie set designer to constructed an office that Jill Tarter might have in a Jill Tarter biopic.
Around the office, which Tarter still visits weekly even though she’s nominally retired, scientists study all the topics that relate to some factor in the Drake equation—that piece of philosophical math developed more than 50 years ago—and breaks down the ingredients that go into the rise of smart, communicative, off-Earth life. In the 33 years since the institute formed, the scientists here and around this whole planet have been getting more tangible results about the possibility that extraterrestrial life might exist—and not just in the usual binary-form answer to the question “Did we intercept a message or not?” Those tangible results come from two main fields: exoplanets and extremophiles.
Since the institute began in 1984, astronomers have discovered two important things: thousands of worlds outside the solar system and increasingly extreme life right here on Earth. The yield of that chemical reaction is the discipline of astrobiology—what scientists call the study of planet habitability, the conditions that cause life to arise, and the search for signs of life (intelligent or not). Astrobiology thus joins the two “ex-” fields together. And by embracing the spectrum of possibilities, from prebiotic chemistry to electromagnetic broadcasts, as all part of the search for life in the universe—something not all scientists do—Tarter has helped grow the institute to nearly one hundred chemists, biologists, computer scientists, astronomers, philosophers, and geologists—a far cry from the single-person endeavor SETI was when Frank Drake did the first Green Bank search.
Some of them work on star formation, others on planet formation and location, and still others on what makes a planet livable. Some dig in to what makes biology come about, some how biology becomes smart and what “smart” even means, and some how we could communicate to that hypothetical smart life and what its communications to us might mean or look like. The part of the SETI Institute that is actually dedicated to traditional SETI—searching for the electromagnetic missives from extraterrestrials—is much smaller than the other branch: the Carl Sagan Center for the Study of Life in the Universe, which covers all the Drake equation factors up to “What fraction of life becomes intelligent?”
All of that more traditional science informs SETI’s likelihood of success. And lately, the odds are looking up, precisely because of how many—and how varied—scientists have found non-Earthly planets and Earthly life to be.
The most interesting of that earthly life comes in the form of so-called extremophiles. Extremophiles are exactly what their name indicates: life that loves extremes. These are the X Games competitors of the biological world. It almost seems like they are trying to one-up each other with weirdness. Some thrive on battery acid, others in the cooling pools of nuclear reactors. They love hugely hot places and really cold ones. The most famous and beloved species, called a water bear or tardigrade, can even survive the vacuum and radiation blasts of space.
Humans once thought life was a rather fragile thing, touchy. It needed just the right Goldilocks conditions to be okay. But scientists have discovered that what’s “right” for the life that’s most like us is actually wrong for life very different from us. As we grow up, we learn that in a cultural and sociological sense. But science was slow to catch on to that same truth in a biological sense.
Earlier last century, even the best biologists thought life needed water, oxygen, and sunlight, just as you learn in elementary school when you’re trying to grow a lima bean in a Dixie cup. Flora and fauna could survive cold, but not too much; heat, but not too much; salty water, but not too salty. It couldn’t hang in highly acidic or very basic places. Its DNA needed the shield of a nucleus.
We were so wrong!
Cracks in that thinking appeared first in the early 1900s. People noticed that their stores of salted cod were going bad. What they didn’t understand was that there were scores of living microscopic animals that survived the salting process and were spoiling their food. Then, in the 1940s, miners found microbes in the seemingly toxic drainage at the Iron Mountain mine. Twenty years later, microbiologist Thomas Brock discovered bacteria in Yellowstone’s otherworldly hydrothermal features—thriving in the hot, acidic environments that bubble up from the innards of Earth. In 1974, NASA Ames scientist R. D. MacElroy gave all of these strange beasts a name: extremophiles.
But “black smokers” really clinched the concept that life goes on basically everywhere. In 1977, scientists and explorers Jack Corliss and Robert Ballard found bacteria around thermal vents on the ocean floor, which pour steam up as if from Dante’s depths. But the bacteria didn’t care that these vents were both brutally cold and unimaginably hot (along with being pitch dark). Nor did they care that no one had noticed their hardiness. They just went about their bacterial business, filling their evolutionary niche like they always had.
Since then, scientists have unearthed even more extreme organisms: endoliths that eat the rock under Antarctic ice, methanogens make me
thane gas under ice in Greenland, Arctic cyroconites that have natural antifreeze proteins, Thiomargarita bacteria that slurp sulfides off Namibia’s coast, bacteria like nitrosomonas that take in chemical energy instead of sunlight, and tardigrades even survive in space sans air or water or the pressure they provide.
With this rainbow of bad living situations that other beings don’t actually find that bad, scientists have been forced into a kind of habitability relativism, in which we can’t project our preferences onto other organisms—a good practice in general. Our optimal happy place is other life’s (usually very small life’s) oppressive environment, and vice versa. The diversity of livable real estate on Earth demonstrates just how many habitable spaces could exist in the universe, if we don’t limit our search only to the neighborhoods exactly like the ones we would personally want to inhabit. So now, scientists can look for myriad conditions (and keep their eyes out for even weirder ones) on other planets or big moons, knowing that the possibility of finding a tiny creature peering back is not totally out of the question.
As Tarter said in a July 2014 talk at NASA Ames Research Center, “Homo sapiens is just one single leaf on a very expansive tree of life, and that tree is really densely packed with organisms that have been finely tuned over millions of years to meet their specific survival needs. Although we know that, I think a lot of our fellow inhabitants of the planet certainly haven’t internalized this idea. Our egos haven’t yet caught up to this scientific understanding. This is a perspective that the natural universe does not share. So get over it.”