In the 1997 film Contact, Jodie Foster’s character "Ellie" Arroway was based on real-life astronomer Jill Tarter.
A photograph of the pair proudly stands in the SETI offices in Mountain View, California. The famed astronomer—known for her work in the search for extraterrestrial intelligence and as the former director of SETI—has been a leader in the field for decades. So you might think Jill Tarter’s drive to answer our most profound question –‘Are we alone?’— was something instilled in her since birth.
However, like many great endeavors, Tarter attributes her career path to serendipity. “I was in the right place, at the right time, with the right set of skills, to have a go at trying to answer this old human question. ‘Are we alone?’ And I just couldn’t imagine anything more exciting to do,” Tarter tells Supercluster.
Photo by Louie Psihoyos for Psihoyos.com
It was the astronomer Stu Bowyer—who, in the 1970s, had wanted to do a SETI search using the UC Berkley 85 foot telescope—that first approached Tarter about working in the field. With little cash, Bowyer had to borrow equipment for the investigation and it was Tarter who had the skills to program the old PDPS computer he’d been given. “Stu came to my office with the cyclops report (a 1971 NASA report that became the basis for SETI) and said he wanted me to join his team and program this computer to do a SETI search.”
“And I just got hooked.”
Yet, a career searching for what Tarter describes as ‘a 9-dimensional haystack for some needle which may or may not exist’ can be frustrating. “If you wake up in the morning and you say to yourself ‘today’s the day, I’m going to find a signal,’ then you are going to go to bed most likely quite disappointed. But if you wake up and say ‘I’m going to figure out a way to make the search better than it was yesterday’—then you are going to find a lot of satisfaction.”
The SETI search is something that “might in fact require multiple generations,” but Tarter remains optimistic about the progress made so far. In 2010, she wrote a paper outlining the challenges they face. Drawing a comparison between the universe and Earth’s oceans, she suggests the amount we’ve so far searched amounts to “just one glass.” But in the last decade, with technology increasing exponentially, Tarter says the answer today would “now be more like a small hot tub.”
This analogy starkly outlines the hurdles ahead, and the frustrations that Tarter and future generations will likely face. However, there are glimmers of hope with emerging technologies like machine learning and neural networks, and advances in optics and mirrors like the upcoming James Webb Space Telescope. Among the game changers in the field of SETI is the growing exoplanet catalog––a relatively new addition to what we can confirm about the cosmos. When Tarter started her SETI work it wasn’t known definitively if planets orbited other stars. And combined with studying extremophiles here on Earth “It just blew our minds, and made it abundantly clear that there could be a lot more potentially habitable real estate out there than we once thought,” she explained.
Even robotic missions within our own solar system hunting for signs of microbial life—such as NASA’s Perseverance Rover—are of huge significance to Tarter and SETI research. “If there is a second genesis in our solar system and life arose independently in multiple places, then I think it’s absolutely a sure bet that life will be ubiquitous.”
“And if there’s a lot of life out there, some of it may have made it to technology.”
But let’s just suppose there was a signal and scientists determined it was in fact from an alien civilization. Then what? Given the vast distances in the universe and the limits to our current technology, you’d be forgiven for thinking the possibility of meaningful communication seems bleak. For Tarter, a better model for thinking about interstellar communication is the one-way transmission. She draws a comparison with the conversations we have with Shakespeare, the Ancient Greeks, or the Romans; “We can’t ask them any questions, but from information transferred over the millennia, we can learn a great deal.”
Maybe this how we should look at any communication with an alien civilization. “Because of the tyranny of light speed, any information that we might glean is going to be telling us about their past.” Although not as exciting as depicted in the movies—in Contact Jodie Foster’s character was able to travel across the universe—finding a signal will help answer at least some of our questions about the cosmos.
“If in general, technologies are long-lived, that means somebody else made it through, and therefore so can we. That’s the most important thing SETI can teach us about a successful detection—that it is possible for us to have a long future”.
Photo: North American AstroPhysical Observatory
For now, much of Tarter’s work is closer to home. She expresses frustration at the time spent with the media, refuting claims of bogus signals. Her recent hobby horse is popularizing the new Rio Scale, a way of analyzing signals on a scale of 0 to 10—like a Richter scale for SETI. So far no signal has made it above a 3. But she is also encouraged by the public appetite for space exploration and thinks that ultimately what this search for life elsewhere gives us is something closer to home. It teaches us about Earth and ourselves. “It’s like holding a mirror. Although we all look different, we are in fact, when compared to something which evolved on a different world, all the same.”
This message could perhaps encourage others to take up the reign of the daunting SETI task. “We have all these challenges that we face, that do not respect national boundaries. Covid has been an example of that. Challenges that need to be solved globally. So I think anything that helps people to change their perspective so they see themselves as Earthlings, that’s really very important. That’s SETI‘s opportunity. To try to change people’s points of view.”
Though perhaps for others, the pure romance of searching the vast ocean of the universe will ensure that we continue with SETI.
“I remember walking along the beaches of the Manasota Key in Florida, on the west coast with my dad, and it was really dark. No street lights, nothing. As we were walking along the beach and looking up at the stars my dad was trying to teach me the constellations. And I just remember having this thought that somewhere out there, around one of those stars there was a small creature walking along the edge of the ocean on their planet, with their parent, looking up and seeing our sun as a star in their sky.”
When I ask Tarter to answer her own question, “Are we alone?” she is coyer. “If I told you that, that would be religion and not science. We need to systematically explore. Eventually, if we have explored until we are too fatigued to do it anymore, we might have to accept the conclusion that we are alone. But that is such a momentous conclusion.”