“Space is big. You just won’t believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it’s a long way down the road to the chemist’s, but that’s just peanuts to space.” — Douglas Adams, “The Hitchhiker’s Guide to the Galaxy”
One hundred thousand quadrillion vigintillion.
That, some nutty professors calculate, is how many atoms there are in the known universe.
That’s a stupefyingly huge number — a 10 followed by 80 zeroes — but it’s nothing compared to the number of times all those atoms have interacted with one another over the past 4.32 quintillion seconds (4.32 with 17 zeroes behind it, equal to 13.8 billion years, the age of the universe).
That unimaginably huge amount of stuff being squeezed and slammed, combined and recombined, churning and mixing, exploding and expanding over that unimaginably long span of time has given rise to, well, everything: stars and galaxies, the 90 or so elements we know of that occur naturally, the planets, our beautiful Earth and all of the life that ever has existed here (over about 3.8 billion years of our orb’s 4.6 billion-year existence,) including, of course, us.
Can there be any doubt that the laws of physics and the mathematical odds are in favor of intelligent life elsewhere in the universe?
“That’s a good story,” said astronomer Dr. Jill Tarter, “but we don’t have any data to back it up yet.”
Curse you, Science!
Tarter, former director of the SETI (Search for Extraterrestrial Intelligence) Institute in Mountain View, California, and now chair emeritus for SETI Research, visits Jackson Hole this week as the second guest of Wyoming Stargazing’s inaugural Science Speaker series. Her presentation, “Searching for Life Beyond Earth,” will start at 7 p.m. Saturday at Walk Festival Hall in Teton Village.
“I’ll show really beautiful images having to do with the cosmos,” Tarter said her presentation, “and try to explain how intimately connected we all are with this vast universe and huge time scale. … I try to challenge people’s perspective, to give them a cosmic perspective. I think that’s an important thing. We’ve got so many challenges on this planet, if we don’t take the larger view — see ourselves as part of one system, that we’re all the same — we’re not going to solve them.”
She also will talk about the niche in space exploration for which she is best known: the search for life outside our planet.
Series off to great start
Dr. Samuel Singer, executive director of Wyoming Stargazing, said this inaugural speaker series represents another jump for the nonprofit. Before this year the organization’s main outreach activity was stargazing parties — both free weekly events and private parties.
“We did 50 more programs this year than last year,” he said, “which is hard to believe with the eclipse mania of last summer, but word got out. I think the trend will continue. The New York Times even mentioned us in its travel section in a piece about the spread and rise of astrotourism.”
The speaker series offers another way for Wyoming Stargazing to attract attention. Judging from how the first event went — astronaut Scott Altman spoke Sept. 8 to a crowd of about 250 adults and students, Singer said — the strategy is working.
“We’re excited about these first four folks,” he said.
Tarter has been someone he has wanted to meet for a long time.
“I remember as a kid, I had the SETI screensaver on my computer,” he said, referring to a program that would turn on when your home computer went idle and would join in the tedious business of searching sections of the sky for possible alien transmissions. “It was the first big scientific organization that I’m aware of that did internet-based citizen science. … I remember staring at my screensaver for big chunks of time.”
Tarter earned her bachelor’s degree in engineering physics in 1966 from Cornell, the only woman in the engineering program at the time. During her first year as a graduate student she learned to program a PDP-8/S computer, one of the first commercially available “microcomputers” (it was about the size of a four-drawer filing cabinet). After Cornell she went to the University of California at Berkeley, where she earned her doctorate in astronomy.
Stuart Bowyer, an astronomy professor at Berkeley and an early SETI researcher, had been given a PDP-8/S computer, which by the late 1970s was already obsolete.
“He said, ‘What the hell do I do with this?’” Tarter recalled. “Someone pointed to me, and Stuart asked me to come to work for him because I could program this thing.”
She began working with Bowyer, using a radio telescope at Mountain View to conduct painstaking surveys of patches of sky in search of extraterrestrial radio emissions. That method was pioneered by Frank Drake, another Cornell astronomer and the creator of the Drake Equation, which estimates the possible number of intelligent civilizations in the Milky Way galaxy. Though Drake’s 1960 examinations of the stars Tau Ceti and Epsilon Eridani turned up nothing, his method remains an essential tool for the search — though on a much grander scale.
“Right now what we’re doing is 14 or 15 powers of 10 more comprehensive than the search Frank Drake did,” Tarter said of 21st-century technology and computational capability. “And it’s only going to get better. We can do today what we couldn’t imagine doing yesterday, and tomorrow we’ll be doing what we can’t conceive of today.”
Tarter has been around to experience the boom. Over her 35-year career she has served as project scientist for NASA’s High Resolution Microwave Survey in 1992 and 1993, which used the 1,000-foot Arecibo Ionospheric Observatory in Puerto Rico, and then as director of Project Phoenix, using instruments in Australia and at the National Radio Astronomy Observatory in Green Bank, West Virginia — where Drake conducted his first probes.
In that time Tarter has worked with many of astronomy’s greatest minds, including the late Carl Sagan.
“He was a colleague and a member of the board of SETI,” Tarter said.
In fact, the SETI Institute’s astrobiology branch is called the Carl Sagan Center.
“He was such a towering figure and a wonderful communication for my generation and generations younger,” she said of Sagan, who died in 1996 at the age of 62.
Sagan, who spent most of his career at Cornell and who won a Pulitzer Prize, two Emmy Awards, a Peabody Award and a Hugo Award, published hundreds of scientific papers. But he also wrote a great amount for the lay audience, turning millions on to the wonders of the night sky. He narrated and co-wrote the 1980 PBS series “Cosmos” — the source of his famous line, “We are all made of star stuff” — and his 1985 novel, “Contact,” was a best-seller that became a hit movie.
The main character of “Contact” is a brilliant young scientist named Ellie Arroway — played in the 1997 film by Jodie Foster — who discovers a strange radio transmission from deep space. Sagan used Tarter’s work as the basis of Arroway’s fictional research, and Tarter met with Foster many times during the making of the movie — enough that Tarter is often said to be the model for the character.
Sagan was a champion of the scientific method — mathematical odds and plausible hypotheses were no substitute for hard evidence and a well-designed experiment — and he applied that rigor to exobiology, a branch of science that once could easily be dismissed as fringe or fantasy.
Tarter follows Sagan’s lead. She describes two general classes of evidence: biological and technological. Biological signatures are things like fossils or even gasses in an atmosphere that could only have been left behind by life processes. While we don’t quite have the ability to do it yet, Tarter predicted that within a decade or two we would be able to systematically analyze the atmospheres of far-off exoplanets, using spectroscopy to detect telltale metabolic byproducts or other such clues.
Technological signatures offer other intriguing possibilities. For example, spectroscopy could someday detect tritium in an atmosphere. Tritium is hydrogen, the most common element in the universe. But instead of having normal hydrogen’s single neutron, tritium, which is produced via nuclear fusion, has three, making it fairly easy to identify. If you detected tritium in some unexpected place, like in the atmosphere of an exoplanet, Tarter said, that could be a sign of an intelligent civilization using nuclear fusion as its main source of power.
“Finding something that doesn’t look natural,” she said, “an alignment of stars or plants for instance — there’s a long, long litany of things we could be looking for with new telescopes, not just intentional messages but things that would indicate a technology.”
Yes, in our backyard
One problem — maybe the problem — is that, as already established, the universe is dauntingly vast. Our search so far has found none of the sort of evidence Tarter describes, but our search so far has covered only an infinitesimal portion of the cosmos. Technological advances are allowing us to look farther and wider, but it’s still slow going.
On the other hand, our own solar system has recently revealed some promising leads. Our explorations of Mars have provided plenty of evidence that the Red Planet at one time had conditions we find conducive to life. And a number of icy moons orbiting Jupiter and Saturn likely have huge amounts of water beneath their frozen exteriors.
“If we find evidence in our own solar system of a second genesis, another form of life, that tells us life is ubiquitous,” Tarter said.
Tarter said the most important thing that we humans do is to explore — “to come up with new answers and solutions to old problems and to think of new questions to ask and to understand our place in the universe.” The search for extraterrestrial intelligence, then, is not some lark, some plot for science fiction. It is the logical and inevitable destination of all of our scientific inquiries. And, even more thrilling, it is the jumping-off point of the next leg of our journey.
Wyoming Stargazing’s Speaker Series continues Oct. 20 with Doug Leonard, professor of astronomy and a supernova expert at San Diego State University.
“He was one of my college astronomy mentors,” Singer said. “I wouldn’t have gotten into astronomy without Doug.”
The series concludes Nov. 9 with a talk called “Preserving Dark Night Skies” by author-conservationist Paul Bogard, who is leading the charge of the dark sky movement.
For tickets or information about the series, individual speakers or Wyoming Stargazing, visit WyomingStargazing.org. ￼