Posts Tagged ‘SETI’

Still Searching: SETI Pioneer Jill Tarter Talks Shutdown, Aliens

28 Apr

For many alien enthusiasts, Jill Tarter is synonymous with the search for extraterrestrial intelligence. As the SETI Institute’s research director — and the inspiration for Jodie Foster’s character in Contact — she’s done more than anyone to raise the search for cosmic company from a fringe effort to serious science.

After receiving a TED prize in 2009, Tarter had grand plans for the Allen Telescope Array, a proposed field of 350 big-nosed radio dishes that would be the world’s only dedicated SETI telescope, as well as its most sensitive. But this week, budget cuts forced the ATA’s existing 42 dishes into hibernation mode. The rest are now just a dream. talked with Jill Tarter about the shutdown and what it means for the future of SETI. The dishes are in hibernation mode now. What exactly does that mean?

Tarter: It means the array runs on a smaller staff. We keep the caretaker staff. We keep power on the antennas, so the cryogenics stay cold and they don’t get harmed. We just put them in a safe mode. But you can’t operate them, you can’t take data. Does that mean you’re expecting to bring it back up?

Tarter: We’re doing everything we possibly can to bring it out of hibernation. But that, you know, that requires new funding.

We’re talking with the Air Force, and we’re hopeful for that. But we also need the public to step up and support SETI research, to keep that on an even keel. This unfortunate situation, coming at just the wrong time, when we were just beginning a two-year search of these Kepler worlds — we hope people understand the irony of that. Tell me about the Kepler project. What were you going to do there?

‘We can expect 50 billion planets in the galaxy, and 500 million of those are likely to be habitable.’

Tarter: Before Kepler launched, we knew about a couple of hundred exoplanets. Most of those were big or right next to their stars. Not likely to be habitable. The Kepler worlds are different. There are 68 of them that are about the same size as Earth, of which it’s calculated that 54 may be in the “Goldilocks” habitable zone. And there’s 1,235 of them altogether, which [extrapolated] gives us the statistic that we can expect 50 billion planets in the galaxy, and 500 million of those are likely to be habitable.

The Kepler results have changed the way we can do our research. We can now point where we know there are likely to be good planet candidates. That’s a change. This is a fantastic new bounty of potential and information. So you had specific plans to go after the Kepler planets directly?

Tarter: Yes. We’d scoped out a two-year observing program. There’s something called a “water hole” from 1 to 10 gigahertz, where the universe is naturally quiet. We want to search through that. That makes it a particularly bad time to be shutting down the telescopes.

Artist's rendition inspired by data from the Kepler telescope, courtesy of NASA.

Tarter: It’s a hugely frustrating time. [SETI senior astronomer] Seth Shostak is all over the place with a great one-liner: “It’s as if the Nina, Pinta and Santa Maria were called back to dry dock.”

The other thing we’re doing now, which we’ve never done before, is trying to get the world involved. We’re trying to open up this search so that it isn’t just done in a silo by a tiny priesthood of astronomers.

Every Friday afternoon for the last year, we’ve saved and uploaded into the cloud huge amounts of data, about 10 terabytes altogether. The idea is to allow people who are good at signal processing to help us develop new algorithms to find new classes of signals. We’ve also just put out the first version of a citizen science participatory opportunity [SETIQuest Explorer], which is in beta test now. It’s our first attempt to see whether people can help us find patterns in the data that we haven’t yet built algorithms for.

Having an active global program — not just turning on your computer, installing software, walking away and never thinking about it again, but getting your brain turned on, thinking about the story, thinking about how you’re connected to the cosmos and everybody else on this planet — that’s another mission. But of course that means we have to get the telescope back on the air before we can carry through on that. Now is not a good time to stop. It’s never a good time to stop. We didn’t build these telescopes to put them into hibernation.

‘We’re trying to get the world involved. We’re trying to open up this search so that it isn’t just done in a silo by a tiny priesthood of astronomers.’ What other approaches are there for SETI?

There’s still SETI@Home, which is run by Berkeley and works on data recorded at the Arecibo Observatory. There’s a new collaborative project started by the Japanese called Project Dorothy. LOFAR, a new telescope that looks for signals at low frequency over the Netherlands, Germany, Holland and the U.K., has begun a SETI program. There’s a little bit of SETI in Australia, and SETI is still ongoing at Institute for Radio Astronomy in Argentina. So there’s hope. The torch is still being carried.

Tarter: Oh, definitely. I’m working harder this morning and yesterday than I ever have before, trying to get the message out. We’re going to find different federal funds, but we really need people invested and engaged and supporting us to keep the funding stable. How important is it to have continuous observations? If we’re targeting individual Kepler planets, the planets will still be there in 10 years.

Tarter: Sure, the planets will still be there. On the other hand, would it make a difference if you discovered a signal today, as opposed to waiting 10 years? I think it would, [especially] in getting people to recognize that their differences are small. That message is an important one. What do you think would happen if we discovered a signal today?

Natural radio emissions from the Andromeda galaxy, courtesy of SETI.

Tarter: It would change everything overnight. SETI wouldn’t have any funding problems anymore. People would be eager to see if there was information in the signal. But even if it was only a cosmic dial tone, with no obviously or instantaneously available information, we’d still learn some very fundamental facts.

We’ll learn that technologies can survive a long time. Unless technological civilizations have long lifetimes, we’re never going to succeed in detecting a signal. We have to be close enough in three-dimensional space, and we also have to overlap in time. In the 10-billion-year history of our galaxy, if civilizations only last for 100 years, there’s not going to be any overlap. If we get a signal, it means that technologies, on average, can last a long time.

I’m not saying we’re going to get extraterrestrial salvation, by any means. But I am saying we’ll learn that it’s possible to survive our technological adolescence. That’s where we’re stuck right now, and there are a lot of indications that we won’t make it out of this. A signal would make all the difference, would show that it’s possible. That somebody else did it.

To donate to the Allen Telescope Array and the Kepler worlds project, go to

Full disclosure: This reporter spent a summer at the SETI Institute.

Images: 1, 2 & 4) SETI Institute. 3) NASA.

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Our Eavesdropping-on-ET Strategy Not Likely to Work

14 Jul

Bad news for SETI: Even with the most sensitive radio telescopes yet designed, humans probably won’t find intelligent aliens by listening in on their phones and televisions, a new study finds.

“Eavesdropping on ET is very hard, even with the latest radio telescopes,” said astronomer Duncan Forgan of the University of Edinburgh, a coauthor of the study. “If we don’t try any other ways of searching for aliens, then we may never find them.”

Forgan and astronomer Robert Nichol of the Institute of Cosmology and Gravitation in the U.K. set out to test the suggestion that rather than building expensive telescopes dedicated exclusively to listening for signals from aliens, SETI — the search for extra-terrestrial intelligence — could be done on the cheap by piggy-backing on other astronomy missions.

Some astronomers hoped SETI searches could ride on the coattails of the planned Square Kilometer Array, which will probe the history of the universe with thousands of small antennas spread out either Australia or South Africa.

“We focused on the SKA because it will be an incredible advancement in radio astronomy,” Forgan said. “It will be the most powerful radio telescope ever built.”

The SKA will also be sensitive in the same frequency range that cellphones, radio and television operate in. If the aliens out there are anything like us, that frequency range is exactly where we should expect to find them, astronomers have suggested.

In 2007, astrophysicists Abraham Loeb and Matias Zaldarriaga of the Harvard-Smithsonian Center for Astrophysics calculated that signals similar to those used in human military radar could be detected from more than 160 light-years away using a telescope in the Netherlands called LOFAR, and more than 650 light-years away using the SKA.

But assuming these aliens have technology like ours, there won’t be enough time to find them, Forgan and Nichol argue. Humans, the only intelligent civilization we know of, have been communicating using radio waves for only about 100 years — and we’re beginning to go quiet. Advances in technology mean less power is needed to broadcast, and digital communication is starting to replace radio altogether.

Forgan and Nichol randomly generated about 500,000 alien civilizations based on current theories of planet formation, and an optimistic guess as to how many would develop life. They then assumed that each civilization broadcasts in radio for 100 years, and they can hear each other from up to 300 light-years away.

“All communication disappears,” the team wrote. Even with a telescope like the SKA, the odds of eavesdropping on another civilization are one in 10 million. The results were posted in a paper on the astronomy preprint website and accepted for publication in the International Journal of Astrobiology.

A more fruitful strategy would be to target our searches, Forgan suggests. We may not be able to hear leaked signals, but we could still pick up a deliberate beacon from a civilization that wanted to announce its presence. A telescope dedicated to searching for such a beacon, like the Allen Telescope Array in northern California, would improve the odds to one in 10 thousand.

Jill Tarter of the SETI Institute thinks Forgan underestimates the usefulness of the SKA. “The SKA is being built with a large field of view and many simultaneous beams, so that there should in fact be significant observing time available for SETI,” she said.

Whatever the odds, Loeb thinks we should eavesdrop, anyway. “Rather than speculate about how generic is our own evolution and whether others will be the same, we should just search,” he said. He points out that a lot of technological advances are driven by social forces. For example, Earth gave off the most radio waves during the Cold War, when radar ballistic missile searches were common.

“Politics are impossible to predict, they don’t follow laws of physics,” he said. “We should just explore the sky, and try to set as strong limits as we can.”

Forgan agrees. “We should always continue to eavesdrop as it is a cheap search method, especially if we piggy-back,” he said. “If you don’t listen, you won’t hear anything.”

Image: SKA

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