[dropcap]When[/dropcap] you’ve spent your career chasing the ultimate, change-everything cosmic brass ring, how do you retire without feeling disappointed? I’ve been asked that question, or some variation, dozens of times in the past month, and I’ve answered it the same way I have over my many decades as a research scientist searching for extraterrestrial intelligence.
I’m not disappointed. I understand how little searching we’ve done so far, and I’m excited about how much we will do in the future. Now it is time for me to shift from looking for extraterrestrial intelligence to looking for intelligent benefactors to help support that quest. I’ve done this before, but now I have to do it with gusto. Now I’m retired.
The existence of life beyond Earth is an ancient human concern. Over the years, however, attempts to understand humanity’s place in the cosmos through science often got hijacked by wishful thinking or fabricated tales. Of particular note, the New York Sun hoaxed its eager readers in 1835 with stories about a splendid civilization of moon-men that had supposedly been revealed by observations made with a 20-foot optical telescope in South Africa. Percival Lowell opened the 20th century with a popular, but false, interpretation of canals built by thirsty Martians to save their planet.
But things got more serious in 1959, with the publication of a paper in the journal Nature marking the beginning of the modern era of the search for extraterrestrial intelligence, or SETI. The paper’s authors, Giuseppe Cocconi and Philip Morrison, recognized that the new science of radio astronomy offered tools — radio telescopes developed from World War II-era radars — with which these old human questions could be explored.
This is what hooked me on SETI.
As I was leaving graduate school in 1974, I was recruited to join a fledgling SETI project at the Hat Creek Observatory in California, mainly because I knew how to program an ancient PDP8/S computer that had been donated to the project. I was alive at just the right time, with just the right skills.
In 1960, the pioneering astronomer Frank Drake, working at the National Radio Astronomy Observatory in Green Bank, W.Va., pointed the Tatel telescope at two nearby, sun-like stars, seeking to detect any radio signals that extraterrestrials might be transmitting, whether for their own purposes or to attract our attention. Drake’s Project Ozma failed to find any engineered signals coming from the vicinity of those stars, but it did detect unanticipated emissions coming from our own technology. To this day, telling the difference between signals that might be “theirs” and those that are ours remains a major challenge.
In his book “Is Anyone Out There?,” written with Dava Sobel, Drake describes an adrenaline-charged episode when he thought he might have found what he was looking for. The SETI research community is small, but almost all of us have shared that incredible experience. As our hardware and software have evolved in sophistication, we’ve built in safeguards that filter out most human-engineered sources of interference. Most, but not all.
This happened to me in the 1990s, in the midst of a decade-long search called Project Phoenix. (It was named to commemorate rising from the ashes of congressional termination of NASA’s SETI program.) With the help of private donations, we transported a shipping container jammed with electronic gear to major observatories around the world.
We would observe simultaneously with a second, smaller telescope located hundreds of miles away. This was our main defense against confusing our signals with theirs. For any signal to be considered a valid candidate for extraterrestrial intelligence, it had to be detected at both sites and had to exhibit behavior consistent with a signal being transmitted from somewhere near the star we were targeting.
In 1997, a lightning storm in Woodbury, Ga., where our second dish was located, fried a disk drive in one of our computers and left us with only the 140-foot telescope at Green Bank for a few days. And that is when things got interesting.
Early one morning, I was preparing to end my shift babysitting the automated detection systems and pack up to head back to California when a clearly artificial signal was detected. The Phoenix system automatically did what it could without the second dish. It pointed away from the target star, and the signal disappeared, then it pointed back at the star, and there was the signal again.
I stopped thinking about packing.
I had an idea and wrote a small program to search our recent data to see if we had detected this signal before. The results revealed that we had indeed, when the telescope was pointed in other directions, and that it was our technology being picked up by the telescope’s peripheral vision. But I was so excited that I misread the numbers. My quick bit of programming, sloppy formatting and rising excitement all conspired to craft a different script.
My colleagues from the day shift arrived to join the action. I sent a quick e-mail to our administrative assistant in California asking her to help change my travel plans and to let my husband know that I would be delayed. Then the doors of the observing room at the base of the telescope swung open to admit a documentary TV crew; months earlier, we had agreed to let them film our work. Now here they were. For hours we ignored the cameras and nodded the venerable old telescope on and off the target star. The signal disappeared and reappeared as expected. We looked up the star and debated what might make it a successful host for another technological civilization.
By mid-afternoon, although the signal had never failed to show up at the right time, we reluctantly concluded that it was not, after all, evidence of a distant civilization. The way the signal’s frequency components were changing because of the Earth’s rotation was wrong. We didn’t know what it was, but we knew what it wasn’t. As I headed off to dinner, again and again I assured the TV crew that this wasn’t it after all; they were more disappointed than we were.