Five Billion Years of Solitude (2 page)

By the mid-2000s, I had followed my curiosity into a career in science journalism, where instead of pestering personal friends and acquaintances with my questions, I could simply pester the experts themselves. Answers to some of my earlier questions had emerged over the intervening years: planets proved quite common around other stars, and since the mid-1990s astronomers had found hundreds of them. These worlds were called “exoplanets,” and most were far too large and far too near their suns to be hospitable to life as we know it. Using large telescopes on the ground and in space, astronomers had even managed to take pictures of a few that were very hot, very big, and relatively nearby. But other questions remained unaddressed: Were there other Earth-size, Earth-like exoplanets in our galaxy and in the wider universe? Was our situation here on Earth average, or was it instead quite special, even unique? Were we cosmically alone? I decided to write this book when I learned just how soon we might gain answers to some of these seemingly timeless questions.

It was 2007, and I was interviewing the University of California, Santa Cruz, astrophysicist Greg Laughlin for a story. During our chat, Laughlin explained that since exoplanet searches were becoming progressively more sophisticated and capable, there would soon be
thousands rather than hundreds of known exoplanets to compare with our own. Astronomy’s next big thing, he suggested, would focus not on the edges of space and the beginning of time, but on the nearest stars and the uncharted, potentially habitable worlds they likely harbored. Near the end of our conversation, he guessed that the first Earth-size exoplanets would probably be found within the next five years. He had graphed the year-to-year records for lowest-mass exoplanets, drawing a trend line through the data that suggested an Earth-mass planet would be discovered in mid-2011. It suddenly seemed I had stumbled upon some magnificent secret, hidden in plain view. The more exoplanet-related press releases and papers I read, the more convinced I became that somewhere on Earth there were scientists who would be remembered in history for discovering the first habitable worlds beyond the solar system, and perhaps even the first evidence of extraterrestrial life. Yet they were largely anonymous, utterly unknown to the average person. I wanted to learn more about them, and tell their stories. One by one, I sought them out.

Most welcomed me with open arms, and the ones who didn’t still politely tolerated me. Many planned for a bright near-future, one in which they would use great, government-built techno-cathedrals of glass and steel on remote mountaintops and in deep space to wring secrets from the heavens and investigate any promising exoplanets for signs of life. Looking further out in time, some even envisioned our culture eventually escaping Earth entirely to expand into the wider solar system and beyond, driven by a curiosity so insatiable and restless that it would forever propel us outward into the endless immensities of new, far-flung physical frontiers. And yet, as I researched the book, I saw many of their boldest hopes dashed as crucial telescopes and missions were delayed or canceled, deferring all those dreams for generations, if not forever. On the verge of epochal revelations, their work had faltered, but not because of any newfound limitations of celestial physics. Instead, rapid progress in the search for life beyond Earth had succumbed to purely human, mundane failings—negligent organizational
stewardship, unsteady and insufficient funding, and petty territorial bickering. Time and time again I felt I was witnessing the planet hunters reach for the stars just as the sky began to fall. And so I became committed to telling not only their personal stories, but also the story of their field, where it came from and where, with a reversal of fortune, it might still go.

The result is the book you now hold in your hands. By necessity, it glosses over or fails to mention numerous discoveries and discoverers that deserve entire shelves of dedicated literature. I hope the knowledgeable reader will forgive my omissions in light of all that this work does encompass. It is a portrait of our planet, revealing how the Earth came to life and how, someday, it will die. It is also a chronicle of an unfolding scientific revolution, zooming in on the ardent search for other Earths around other stars. Most of all, however, it is a meditation on humanity’s uncertain legacy.

This book’s title,
Five Billion Years of Solitude
, refers to the longevity of life on Earth. Life on this planet has an expiration date, if for no other reason than that someday the Sun will cease to shine. Life emerged here shortly after the planet itself formed some four and a half billion years ago, and current estimates suggest our world has a good half billion years left until its present biosphere of diverse, complex multicellular life begins an irreversible slide back to microbial simplicity. In all this time, Earth has produced no other beings quite like us, nothing else that so firmly holds the fate of the planet in its hands and possesses the power to shape nature to its whim. We have learned to break free of Earth’s gravitational chains, just as our ancient ancestors learned to leave the sea. We’ve built machines to journey to the Moon, travel the breadth of the solar system, or gaze to the edge of creation. We’ve built others that can gradually cook the planet with greenhouse gases, or rapidly scorch it with thermonuclear fire, bringing a premature end to the world as we know it. There is no guarantee we will use our powers to save ourselves or our slowly dying world and little hope that, if we fail, the Earth could rekindle some new technological civilization in our wake of devastation.

In the long view, then, we are faced with a choice, a choice of life or death, a choice that transcends science to touch realms of the spiritual. As precious as the Earth is, we can either embrace its solitude and the oblivion that waits at world’s end, or pursue salvation beyond this planetary cradle, somewhere far away above the sky. In our lives we all in some way contribute to this greater choice, either drawing our collective future down to Earth or thrusting it out closer to the stars. Some of the people in this book have devoted themselves to seeking signs of other, wildly advanced galactic cultures, hoping to glimpse our own possible futures via interstellar messages carried on wisps of radio waves or laser light. Others closely study the evolution of Earth’s climate over geological time, trying to pin down the limitations of habitability on our own and other worlds. A few have become makers of maps and crafters of instruments, and strive to find the most promising worlds that untold years from now could welcome our distant descendants. All seem to believe that in the fullness of planetary time any human future can only be found far beyond the Earth. You will find their tales, and others, recorded in these pages.

I won’t pretend to know what our collective choice will be, how exactly we would embark on such an audacious adventure, or what we would ultimately find out there. I am content to merely have faith that we do, in fact, have a choice. Similarly, I can’t suggest that we simply ignore all of our planet’s pressing problems by dreaming of escape to the stars. We must protect and cherish the Earth, and each other, for we may never find any other worlds or beings as welcoming. Even if we did, we as yet have no viable way of traveling to them. Here, now, on this lonely planet, is where all our possible futures must begin, and where I pray they will not end.

LEE BILLINGS
NEW YORK CITY, 2013

Looking for Longevity

O
n a hillside near Santa Cruz, California, a split-level ranch house sat in a stand of coast redwoods, the same color as the trees. Three small climate-controlled greenhouses nestled alongside the house next to a diminutive citrus grove, and a satellite dish was turned to the heavens from the manicured back lawn. Sunlight filtered into the living room through a cobalt stained-glass window, splashing oceanic shades across an old man perched on a plush couch. Frank Drake looked blue. He leaned back, adjusted his large bifocal glasses, folded his hands over his belly, and assessed the fallen fortunes of his chosen scientific field: SETI, the search for extraterrestrial intelligence.

“Things have slowed down, and we’re in bad shape in several
ways,” Drake rumbled. “The money simply isn’t there these days. And we’re all getting old. A lot of young people come up and say they want to be a part of this, but then they discover there are no jobs. No company is hiring anyone to search for messages from aliens. Most people don’t seem to think there’s much benefit to it. The lack of interest is, I think, because most people don’t realize what even a simple detection would really mean. How much would it be worth to find out we’re not alone?” He shook his head, incredulous, and sunk deeper in the couch.

Besides a few extra wrinkles and pounds, at eighty-one years old Drake was scarcely distinguishable from the young man who more than half a century earlier conducted the first modern SETI search. In 1959, Drake was an astronomer at the National Radio Astronomy Observatory (NRAO) in Green Bank, West Virginia. He was only twenty-nine then, lean and hungry, yet he already possessed the calm self-assurance and silver hair of an elder statesman. At work one day, Drake began to wonder just what the site’s newly built 85-foot-wide radio dish was capable of. He performed some back-of-the-envelope calculations based on the dish’s sensitivity and transmitting power, then probably double-checked them with a growing sense of glee. Drake’s figuring showed that if a twin of the 85-footer existed on a planet orbiting a star only a dozen light-years away, it could transmit a signal that the dish in Green Bank could readily receive. All that was needed to shatter Earth’s cosmic loneliness was for the receiving radio telescope to be pointed at the right part of the sky, at the right time, listening at the right radio frequency.

“That was true then, and it’s true today,” Drake told me. “Right now there could well be messages from the stars flying right through this room. Through you and me. And if we had the right receiver set up properly, we could detect them. I still get chills thinking about it.”

It didn’t take long for Drake to discuss the wild prospect with his superiors at NRAO. They granted him a small budget to conduct a simple search. During the spring of 1960, Drake periodically pointed the 85-footer at two nearby Sun-like stars, Tau Ceti and Epsilon Eridani, to
listen for alien civilizations that might be transmitting radio signals toward Earth. Drake called the effort “Project Ozma,” after the princess who ruled over the imaginary Land of Oz in Frank Baum’s popular series of children’s books. “Like Baum, I, too, was dreaming of a land far away, peopled by strange and exotic beings,” he would later write.

Project Ozma recorded little more than interstellar static, but still inspired a generation of scientists and engineers to begin seriously considering how to discover and communicate with technological civilizations that might exist around other stars. Over the years, astronomers used radio telescopes around the world to conduct hundreds of searches, looking at thousands of stars on millions of narrowband radio frequencies. But not one delivered unassailable evidence of life, intelligence, or technology beyond our planet. The silence of the universe was unbroken. And so for more than fifty years Drake and his disciples played the roles of not only scientists but also salespeople. For the entirety of the discipline’s existence, SETI groups had been searching nearly as ardently for sources of funding as they had for signals from extraterrestrials.

Early on, governments were quite interested—SETI was briefly one of the scientific arenas in which the United States and the Soviet Union grappled during the Cold War. What better propaganda victory could there be than to act as humanity’s ambassador to another cosmic civilization? What invaluable knowledge might be gained—and exploited—from communication between the stars? In 1971, a prestigious NASA commission concluded that a full-bore search for alien radio transmissions from stars within a thousand light-years of Earth would require an array of giant radio telescopes with a total collecting area of between 3 and 10 square kilometers, built at a cost of about $10 billion. Politicians and taxpayers balked at the price tag, and SETI began its long descent from political favor. The trend of null results stretched out over decades, and already scarce and fickle federal funding for American SETI efforts progressively dwindled. A glimmer of hope emerged in 1992, when NASA launched an ambitious new SETI
program, but congressional backlash shuttered the project the following year. Since 1993, not a single federal dollar had directly sponsored the search for radio messages from the stars. Drake and a group of his disciples had suspected what was coming, so in 1984 they formed a nonprofit research organization, the SETI Institute, to more easily solicit financial support from both the public and private sectors. Headquartered in Mountain View, California, the SETI Institute began to thrive in the mid-1990s through a combination of research grants and private donations from starry-eyed and newly wealthy Silicon Valley technologists. Drake served as the Institute’s president from its founding until 2000, before transitioning into an active retirement a couple of years after the turn of the millennium.