Tag Archives: SETI

A cosmic perspective with Jill Tarter of SETI

Jill Tarter thinks that Craig Venter and Daniel Cohen may not have been bold enough when they declared in 2004 that the 21st Century would be the century of biology.

Jill Tarter

The SETI Institute’s Jill Tarter spoke recently at the Rose City Astronomers in Portland, Oregon. (Photo: Greg Scheiderer)

“I think the 21st Century is going to be the century of biology on Earth—and beyond,” Tarter declared during a talk at last month’s meeting of the Rose City Astronomers in Portland, Oregon. Tarter, the Bernard M. Oliver Chair for SETI at the SETI Institute and former director of the Center for SETI Research, thinks there are many ways we might find extraterrestrial intelligence. We might discover it through biomarkers or even artifacts in our own solar system. We could assay the atmospheres of exoplanets looking for biosignatures. We could spot alien “work product” such as structures or signs of engineering. We might even export it, traveling to the Moon, Mars, or even other star systems.

“I think life beyond Earth is a good bet in this 21st Century,” Tarter said, “and when you begin to think about that kind of thing, you really have to reorient your point of view, your perspective. You have to start talking about here and now in a different way, a much bigger point of view, a cosmic perspective.”

Tarter feels that our perspective has changed much since the advent of the space age. Photographs like the Apollo 8 Earthrise or “selfies” by Voyager and Cassini have helped make that happen. We’ve also looked far into the past in viewing distant galaxies.

In the time we’ve been involved in SETI, Tarter says there have been two gamechangers: extremeophiles and exoplanets.


Photos from Space, such as Earthrise by astronaut Willam Anders from Apollo 8, have changed our global perspective. (Photo: NASA)

“Extremeophiles are life as we did not know it until a just few decades ago,” she said, “thriving in places that we once thought completely hostile to life, and they are now illuminating the amazing possibilities for life on our own planet by suggesting more potentially habitable real estate within our solar system and out into the cosmos.”

Similarly, this discovery of thousands of exoplanets has given us more places to look for life.

“Today we know that there are more planets than stars in the Milky Way, and that’s a fundamental change in our perspective,” Tarter said. “When I was a student we knew of nine planets—then lost one!—and didn’t know whether planets would be plentiful around other stars.”

“There is more potentially habitable real estate out there than we ever imagined,” she added, stressing the potential. “We have no idea whether any of it is, in fact, inhabited, but that’s what this century is going to tell us.”

Tarter noted that a big assumption of SETI is that since our technology is visible from a distance, that alien technology might be as well. So we’re looking for something engineered, not a natural occurrence of astrophysics.

“Whether or not SETI succeeds with its optical, infrared, radio searches for signals is going to depend on the longevity of technologies,” Tarter explained, “because unless technologies, on average, last for a long time, there are never going to be two technologies close enough in space to detect one another and coeval in time—lined up at the same time in this ten billion year history of the Milky Way galaxy.”

Tarter said that, in 50 years of SETI, we’ve searched an amount of the cosmos that compares to a 12-ounce glass of water out of the total of Earth’s oceans, so it’s not so surprising that we haven’t yet caught a fish. She adds we’ve been limited by our technology.

“We are beginning to build tools that are commensurate with the vast size of this search, and we understand that the ocean is vast and we are still very, very motivated to go and find what might be out there,” Tarter said. The Allen Telescope Array is a big part of that; you can follow the search at setiquest. There are dozens of other instruments that may provide data to help with SETI, and more than a half-dozen on the drawing boards for the next decade or so.

“This is a hard job,” Tarter said. “This is a lot of very difficult technology to get this job done.”

“Whether or not SETI succeeds in the near term, it has another job to do,” Tarter concluded. “Whether or not it ever finds a signal, it has another job to do. And that is holding up a mirror to all of us on this planet and showing us that in that mirror, when compared to something else out there, we are all the same. Talking about SETI, thinking about SETI, listening to talks about SETI, helps to transfer and to encourage this cosmic perspective. It helps to trivialize the differences among us.”

Tarter encouraged everyone to go home and set their discriptions on their social media profiles to “Earthling,” and to start thinking and acting from that perspective.

“SETI is a very good exercise at working globally to solve a problem,” she said, “and there are many problems that we are going to have to solve quickly in the near term, and do so as a global community.”


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Battling the giggle factor in the search for extraterrestrial intelligence

Dr. Bernard Bates is fascinated by the search for extraterrestrial intelligence, but acknowledges there’s a certain “giggle factor” about the endeavor even as 21st-Century observatories discover planets in orbit around faraway stars on an almost daily basis. Bates, astronomy instructor at the University of Puget Sound, gave an informative and humorous talk this week titled, “The Quiet Sky: Searching for Extraterrestrial Intelligence.” The event at the Swiss Pub in Tacoma was part of the Science Café series presented by the Pacific Science Center and KCTS9 television.

SETI is listening

SETI is listening, but is anyone talking?

Surely part of the giggle factor comes from a half century of listening for electromagnetic transmissions from ET without hearing a peep. Bates said as technology improves so does the hunt, and suggests we give it another 40 years or so.

“If Moore’s law [about rapidly doubling computer power at lower cost] continues, if we don’t stumble upon someone by 2050, we’ve done something wrong,” he said.

That something could be in the design of the experiment.

“The worst assumption we made was that somebody is out there transmitting,” Bates said. “Someone would have to come up with funding on another planet to just send out signals for no apparent reason for a long time.”

Perhaps cash-strapped governments in other systems decided it was cheaper to just listen. Earthlings, on the other hand, have been broadcasting for a little over a century, and the original transmissions of Gilligan’s Island are now crackling out near Theta Boötes. Bates said if we were out there we would figure it out.

“We are really good at what we do. With the technology we have right now, we could find ourselves a quarter of the way across the galaxy,” he said.

It has been 50 years since Frank Drake cooked up the equation which now bears his name as a device for thinking about the factors that affect the chances of intelligent, radio-beaming civilizations appearing around the galaxy. In 1961 all we had for the seven variables were wild guesses. But now we have a pretty good idea about the astronomical variables: the rate of star formation, the fraction of stars with planetary systems, and the number of planets in each system that could support life. That part of the Drake equation suggests there should be 10 civilizations in the galaxy that are emitting electromagnetic signals. Bates said we’re still a little fuzzy on the rest of the variables.

“All of those cannot be incredibly small probabilities, because we’re here,” he noted, so the final answer has to be at least one. “But we just don’t know. Each of those variables represents an area of active research in different disciplines.”

Why all the fuss about SETI? Bates said his nine-year-old daughter drove the point home when she observed recently that she never sees two of anything. There is either just one, or there are many. Bates thinks that may go for extraterrestrial life, too.

“If we find a second genesis within the solar system that means there are probably a lot of them,” he said. “It’s hard to believe that there would only be two examples of life originating in the entire galaxy.”

Bates thinks most of the people working in the field believe there is at least simple life out there.

“It’s complex life that is hard,” he said. “Intelligence might be something that is so rare or so hard to come by that it never appeared again. There might be so many little accidents that had to happen in order for intelligent life to appear that we’re just it.”

Bates thinks we should keep at it, even if we don’t have a clear signal from another civilization by 2050.

“In the end, the worst that could happen is that we just give up and say, ‘OK we’re it. There’s no one else out there to talk to.’”

You can view the entire talk by Bates on the KCTS9 website.