"The cosmic haystack"
HAT CREEK, Calif. — E.T. might be phoning, but do we care enough to take the call?
Operating on money and equipment scrounged from the public and from Silicon Valley millionaires, and on the stubborn strength of their own dreams, a band of astronomers recently restarted one of the iconic quests of modern science, the search for extraterrestrial intelligence — SETI, for short — which had been interrupted last year by a lack of financing.
Early in December, a brace of 42 radio telescopes, known as the Allen Telescope Array, nestled here in the shadow of Lassen Peak, came to life and resumed hopping from star to star in the constellation Cygnus, listening for radio broadcasts from alien civilizations. The lines are now open, but with lingering financial problems, how long they will remain that way is anybody’s guess.
These should be boom times for those seeking out aliens, or at least their radio proxy.
Astronomers now know that the galaxy is teeming with at least as many planets — the presumed sites of life — as stars. Advanced life and technology might be rare in the cosmos, said Geoffrey W. Marcy, the Watson and Marilyn Alberts in the Search for Extraterrestrial Intelligence professor at the University of California, Berkeley, “but surely they are out there, because the number of Earthlike planets in the Milky Way galaxy is simply too great.”
A simple “howdy,” a squeal or squawk, or an incomprehensible stream of numbers captured by one of the antennas here at the University of California’s Hat Creek Radio Observatory would be enough to end our cosmic loneliness and change history, not to mention science. It would answer one of the most profound questions humans ask: Are we alone in the universe?
Despite decades of space probes and billions of NASA dollars looking for life out there, there is still only one example of life in the universe: the DNA-based web of biology on Earth. “In this field,” said Jill Tarter, an astronomer at the SETI Institute in Mountain View, Calif., the “number two is the all-important number. We count one, two, infinity. We’re all looking for number two.”
But the story of SETI is the story of a dream deferred by politics, a lack of money and the technological challenges of searching what astronomers call “the cosmic haystack”: 100 billion stars in the galaxy and 9 billion narrow-band radio channels on which aliens, if they exist, might be trying to hail us.
Politics and the recession have crimped astronomers’ budgets and left the institute’s scientists with a kind of siege mentality. Last spring, the University of California ran out of money to run the Hat Creek observatory, forcing the Allen telescopes into hibernation. In order to continue the search, astronomers are negotiating a deal to share the telescopes with the Air Force, which wants to use them to track satellites and space junk.
No federal funds have been spent searching for radio signals from extraterrestrials since 1993.
A recent visit to the SETI Institute’s Mountain View offices found many of the cubicles empty and the corridors eerily quiet. Last summer, as the Allen telescopes slumbered, weeds grew around them.
998,000 Stars to Go
The story begins with a young radio astronomer named Frank Drake, who pointed an antenna from the National Radio Astronomy Observatory in Green Bank, W.Va., at a pair of stars in 1960, wondering if he could make contact with anything or anyone.
All he got was static, but the hook was set.
In 1971, NASA held a workshop led by Barney Oliver, the research chief of Hewlett-Packard, that concluded the best way to find extraterrestrials was with a $10 billion array of giant radio telescopes called Cyclops. The price tag — as well as the subject — set off alarm bells that still reverberate.
In 1978, Senator William Proxmire of Wisconsin, an outspoken critic of what he considered wasteful government spending, awarded one of his infamous “Golden Fleece” awards to the hunt for aliens, and in 1993, a NASA-sponsored survey for signals from 1,000 nearby stars was canceled by Congress. With the help of friends like Dr. Oliver in the Silicon Valley, Dr. Tarter and her colleagues took the search private.
As the director of SETI research at the institute, Dr. Tarter, 67, has become the public face of the cause, and she was consulted by the actress Jodie Foster about her portrayal of Ellie Arroway, a radio astronomer who finds a signal, in the movie “Contact.”
Dr. Tarter was recruited in 1976, when, as a postdoctorate student at Berkeley, she read the Cyclops report, a rite of passage for most alien-oriented astronomers.
“You didn’t have to ask a priest or philosopher about life in the universe,” Dr. Tarter said. But she realized she was in the first generation who could conduct experiments about it. A half-century and roughly 2,000 stars later, humanity is still officially alone.
Dr. Drake is undaunted, noting that there are 100 billion suitable stars in the galaxy. His personal estimate, based on an equation he invented in 1961, is that there are 10,000 technological civilizations in the galaxy, one per million stars.
“I’ve known all along we have to look at a million stars,” he said. Now a cherubic 81, Dr. Drake is a professor at the University of California, Santa Cruz, and a former chairman of the SETI Institute.
The Allen Array, which was designed to find Dr. Drake his million stars, is named after Paul G. Allen, the Microsoft founder and philanthropist, who put up $25 million to get the project going. Jointly owned and operated by the University of California, Berkeley, and the SETI Institute, it was to consist of 350 antennas, 20 feet in diameter, that were to be mass-produced like satellite dishes.
The full array would be able to map a swath of sky several full moons in diameter in only 10 minutes, or the whole sky in a night — of great interest to astronomers and, as it turned out, to the military.
But Mr. Allen’s contribution was only enough to build 42 antennas, which started operating in 2007. The astronomers say that another $55 million would complete the array, but there have been no volunteers yet.
The project got a lift in 2009 when Dr. Tarter won a $100,000 prize and “One Wish to Change the World” at the TED conference — short for Technology, Entertainment and Design — in Long Beach, Calif. Her talk there began, “The story of humans is the story of ideas.” It elicited a donation of valuable equipment from Dell and Intel.
The project got another lift — mainly psychological — last year when NASA, whose Kepler spacecraft is beaming back news about the patch of Cygnus that it surveys, published its first list of 1,235 exoplanet candidates.
As Dr. Tarter told a conference of exoplanet hunters recently: “We’re not just pointing at stars. We’re pointing where you have shown us there are planets, and perhaps technologists.”
But the recession and the cutbacks that followed wiped out the university’s funds to run the Hat Creek observatory just as it was getting started on a survey of Kepler’s planets. The Allen telescopes went quiet, and the astronomical staff left.
An appeal for financing went out on the institute’s Web site, which eventually brought in about $220,000 — roughly two months’ worth of operating expenses. Meanwhile, the Air Force was interested in using the radio telescopes.
The array, Dr. Tarter explained, turns out to be adept at tracking satellites and space junk, a possibility first identified as early as 2004 in a memo by her husband, William Welch, a radio astronomer at the University of California, Berkeley, who is known as Jack. “There’s a long tradition of radio astronomy and the military scratching each other’s backs,” Dr. Tarter said.
Under terms of an agreement still being negotiated, the Air Force will pay for a share of the operations at Hat Creek, which costs about $1.5 million (plus another $1 million a year to pay the astronomers). The money raised so far will buy a few months at best.
Welcome All Species
The astronomers started bringing their equipment back to Hat Creek in September. The place looked neglected.
“Nobody had cut the weeds,” Dr. Tarter said. “It looked so sad.”
Early in December, when Dr. Tarter and Dr. Welch returned to Hat Creek in Dr. Welch’s Cessna with a reporter in tow, the weeds had been cut and the antennas were majestically turning to a music only they could hear. Scattered across a meadow, they resembled the forest of satellite dishes you see outside events like the Super Bowl.
Nearby in an unassuming ranch house, racks of electronics and computers hummed with life. The doormat read, “Welcome All Species.”
Inside, Dr. Tarter plopped down in front of a computer and watched with a suspicious eye as the display popped with a row of numbers indicating that a narrow-band signal — the signature of an artificial source — had been detected.
She takes great pride in the fact that she and her colleagues have never published a false alarm, and she nodded approvingly as the telescope and computers went through the process of eliminating the new signal from consideration. The Earth’s motion will cause the frequency of a signal from the sky to drift in frequency, for example. The checklist has grown over the years, she said.
Within a few minutes they were back scanning a new part of the spectrum. The computers will check a persistent signal five times, moving the telescope on and off it, before calling someone to discuss it — “whoever is on the desk,” Dr. Tarter said.
The next step would be to call the director of an observatory to the west (since that is the way the sky rotates) and ask for continued observation.
“We’ve gotten six hours into it four times,” Dr. Tarter said. One dramatic moment was in 1998, when Dr. Tarter and her colleagues were working at the observatory in Green Bank, W.Va., and had a signal they could just not eliminate.
Finally they figured out that they were actually receiving transmissions from the European SOHO satellite.
“We went to bed,” Dr. Tarter said.
“It was a real adrenaline pumping time,” she added. “I can’t imagine what the real deal will be.”