Astronomer Jill Tarter wants us all to ask the question, “Are we alone?” As director of the SETI Institute (it stands for the Search for Extraterrestrial Intelligence), Tarter is dedicated to seeking the answer, as well as to imparting upon one and all the importance of the search. In 2009, Tarter was awarded the prestigious TED Prize and founded the website SETILive.org, where people from around the world can register and help with the hunt for alien signals. Tarter’s wish: to “empower Earthlings everywhere to become active participants in the ultimate search for cosmic company.” Ruling out extraterrestrial intelligence at our current point of research, Tarter says, would be akin to scooping one glass of water from the ocean and concluding that there are no fish.

In the three years since Tarter’s TED Prize, the SETI Institute has continued its search, amassed a huge wealth of data and even begun identifying Earth-like planets. They’ve also continued their mission of outreaching their message and educating the public about the full scale of possibilities out there. To that end, Tarter created the TED-Ed lesson, “Calculating the Odds of Intelligent Alien Life,” stressing the full scope of how much is left to be discovered.

But SETI, like many scientific endeavors, has struggled with persistent funding problems. Their newest initiative is a partnership with Uwingu, a private company whose mission is to create a new way to fund research. SETI and Uwingu have been working on apps that will support space exploration as they educate. However, Uwingu needs the funds to launch their products. The company is looking to crowdsource $75K through IndieGoGo.com before September 14. Which means that you can pitch in to help.

Below, read an impassioned letter from Jill Tarter about why the success of this fundraising effort is so crucial, and so exciting.

 ”We all have a vested interest in this one — let’s get Uwingu launched!

Independent of the November presidential election results, future funding for scientific research (especially curiosity-driven, space-related exploration, research and education) will be declining into the foreseeable future.  The drop will be steeper if sequestration is triggered in the federal budget process.  As we wring our hands and lament one another, the phrase ‘alternative funding approaches’ repeatedly crops up in the conversation. But who or what are these?  And how do we access them?  Is there any there, there?

Uwingu LLC is doing more than wringing their collective hands — they are trying to become a source of alternative funding for us! 

This small startup intends to launch their product line in late October (just in time for the Christmas shopping season) and then pool the profits from their marketing efforts to create a fund whose main function will be to make research grants to those of us who can make the best cases for our research proposals.  Will it work?  Who knows? The folks behind this are some of the superstars in our astronomical universe (Alan Stern, Geoff Marcy and a handful of others), but that doesn’t mean they will succeed at making money. Can they really create something like an ‘Angry Birds for space’?  Certainly they won’t succeed if they can’t get started.

Uwingu envisions a $10M-100M annual portfolio for grant making.  That’s small compared with NASA or NIH research budgets, but significant on the scale of NSF astronomy, and I’ll bet it could nicely finance some of your own research ambitions.  But there’s a HUGE long way from here to that lofty goal.  As with any startup, funds are needed to provide early support for the team until receipts from sales start paying the bills and earning a profit.  I want to give them a chance, and I hope you’ll join me.  Uwingu estimates that they will need $75,000 to get started and they are trying to raise that money by crowdfunding at Indiegogo.com.  There are only 7 days left to that campaign, and they still need to raise another $40,000.  You can help them, and perhaps also help our SETI team at the SETI Institute.

Uwingu will evenly split every dollar they raise above their $75,000 threshold with us.  So I’ve got a very personal and vested interest in reaching out to you to become a supporter of this new venture.  Our own SETI team is in dire need of funding — these early returns will be most welcome — but it is the future opportunities that have compelled me to work with Uwingu rather than just asking for your direct support of SETI research and the Allen Telescope Array.  Bricks and mortar, or in our case antennas, are known to be much easier philanthropic ‘sells’ than funding for annual operations and upkeep. Many of you helped us out last summer when we asked for additional funds to cover the expenses of bringing the ATA out of the hibernation necessitated by the withdrawal of our UC Berkeley operating partners when they ran out of funding.  We are back on the air at the ATA studying all the newly discovered exoplanets!  SRI International Inc. is our new partner in the array, but we still need to find funding for our small team of SETI researchers who are constantly coming up with ideas of how to improve the ongoing searches.  We will need these funds this year, and next, and on into the future.  As part of our overall fundraising portfolio, it would be wonderful to be able to propose to the Uwingu Fund for supporting our team each year, and implementing their clever ideas.

Entrepreneurial space ventures intend to make a profit for their shareholders and founders — and in doing so change the way we access space.  Uwingu LLC intends to make a profit for those of us wanting to pursue space exploration, research and education.  Please help them and our SETI team by over subscribing this round of crowdsource fundraising.  Let’s start creating those necessary ‘alternative funding approaches’ today.” 

Become a Uwingu sponsor by heading to this website.

How many detectable alien civilizations are out there in our galaxy? In 1961, astronomer Frank Drake developed an equation to estimate the number. Now data journalist David McCandless, who gave the talk “The beauty of data visualization” at TEDGlobal 2010, has created an information graphic for the BBC calculating the Drake Equation — with a twist. It’s interactive, and you can be as optimistic or skeptical as you like as you set the value of each variable in the equation. Any tinkering leads to highly different conclusions.

Jill Tarter, the head of the SETI Institute, would no doubt set her variables on the optimistic side. Tarter gave the wonderful TED-Ed lesson “Calculating the Odds of Intelligent Alien Life,” which explains the Drake Equation and its many variables. Tarter won the TED Prize in 2009 and called for more people to join the search for extraterrestrial life. “From my perspective, we live on a fragile island of life in a universe of possibilities,” says Tarter in her talk. “So what exactly is SETI? Well, SETI uses the tools of astronomy to try and find evidence of someone else’s technology out there. Our own technologies are visible over interstellar distances, and theirs might be as well … SETI doesn’t presume the existence of extraterrestrial intelligence; it merely notes the possibility, if not the probability in this vast universe, which seems fairly uniform.”

Chris Anderson, TED’s intrepid curator who made the TED-Ed lesson “Why can’t we see evidence of alien life?,” would be optimistic too. “In the past year, the Kepler space observatory has found hundreds of planets just by nearby stars. If you extrapolate that data, it looks like there could be half a trillion planets just in our own galaxy,” he says. “If only one in 10,000 has conditions that might support a form of life, that’s still 50 million possible life-harboring planets right here in our Milky Way.”

But the real question is — how optimistic or skeptical will you be as you play with McCandless’ interactive data set? View the full chart here >>

As Jill Tarter writes, “[SETI Live!] is an experiment to see whether an army of citizen scientists, working with data streaming from the Allen Telescope Array, can recognize, remember and classify patterns, often multiple patterns, well enough to see if there is anything that could be an ET signal requiring immediate follow-up. We don’t know whether it will work. At a minimum, we may learn enough about how humans try to work through the complex mixture of detected signals so that we can teach SonATA (the SETI computer system at the telescope array) how to do the job in the future. Or we may conclude that these bands of data must remain unusable, but — having solved the technical problems of allowing citizen scientists to work in real time — we may have set the stage for yet other, unrelated applications. We may come to understand that, with clever scheduling, we can observe some of these frequency bands when the sources of interfering signals aren’t in the sky. And of course, we may find what we are looking for — we may find a signal from a distant technology that we would otherwise have overlooked.”

To celebrate the launch of SETI Live!, the cable channel Science has organized a month of programming called “Are We Alone? Month.” As part of this ongoing programming, tonight at 10pm EDT, experts including Nick Sagan and Jill Tarter come together to explore how alien life might communicate with Earth in the debut of “Alien Encounters.” SCIENCE concludes this month of all-new programming by presenting firsthand accounts from NASA astronauts who witnessed the mysterious with “NASA’s Unexplained Files” on Tuesday, March 27, at 10pm EDT.

At TED2012, astronomer Arfon Smith presented a new part of the wish. The Allen Telescope Array is looking for signals from extra terrestrial intelligence on radio frequencies, and a stream of realtime data comes into a spectacular new citizen science project – SETILive. They have just three minutes to classify the data coming in before the telescope moves on, and that’s where you come in. In those three minutes, citizen scientists like yourself can comb through the data looking for unusual signals.

In the past decade we have discovered an extraordinary number of planets orbiting other stars — 1,500 of them, in fact. We’ve discovered so many, we now believe other solar systems are commonplace. In December 2011, NASA announced the discovery of the first exoplanet in the “habitable zone” — a planet where liquid water can exist on the surface.

SETILive is targeting the 1500 Kepler candidates, looking for signs of life, and they need your help.

Take part in the search for extraterrestrial life>>

Already designed, just in case... RT @EchoLilyMai: @the_zooniverse If I find an alien will I get a badge? :)

—
SETI Live (@SETILive) February 29, 2012

Last night at the Galapagos Art Space in Brooklyn, Nobel laureate Sir Paul Nurse moderated a discussion centered around the age-old question: Are we alone? Four scientists, including 2009 TED Prize winner Jill Tarter, shared their latest projects, which are better equipping Earthlings to answer this exciting question.

Steven Squyres, who works on NASA’s Spirit Mars Rover mission, announced that recent studies of Martian rock samples from 2005 show evidence of a wet, non-acidic environment that could have been favorable to life at one time. Lab tests confirmed the presence of high concentrations of carbonate, a precipitate of water. Carbonate dissolves in acid, so the remainder of carbonate in these rocks suggests neutral, life-friendly conditions. Squyers also mentioned the possibility for a life-friendly environment on Jupiter’s moon, Europa. Beneath Europa’s frozen outer layer may be an ocean supported by the moon’s internal heat, which could provide the metabolical energy necessary for life.

David Carbonneau explained how his hunt for exoplanets — planets orbiting nearby sun-like stars — could lead to the discovery of life elsewhere. Locating exoplanets involves monitoring certain constellations for eclipses caused by exoplanets passing by stars. As part of the NASA Kepler Team, Carbonneau searches for Earth-like planets that orbit their star’s habitable zone where there is potential for liquid water and life to exist.

Michael Russell proposed that our search for life shouldn’t be guided by the question, “What is life?” but rather “What does life do?” By studying the chemical and biological origins of early life on earth, particularly the circumstances under which protein and RNA came about, he says our search for life elsewhere can be better informed.

Jill Tarter spoke about her latest work with SETI to build the Allen Telescope Array in northern California. So far they’ve built 42 dishes, but hope to fill out the array with 350. The dishes will scan 24/7 for radio signals from afar. Any signal discovered would have originated in the past (due to the time taken for the signal to travel vast intergalactic distances), and most likely would come from an older civilization that’s had technology for longer than Earth. While Jill admitted that we may be searching for the wrong thing, or we may not yet have the technology to recognize signals from intelligent extraterrestrial life, she affirmed that we should keep looking and push technology ahead to better our chances.

At the event’s conclusion, Sir Paul Nurse asked Jill her opinion on Stephen Hawking’s statement that humans should avoid alien contact because they would most likely be hostile. She replied that if she discovered an alien signal, first of all, she would have a glass of champagne to celebrate. Then, she would have faith that the likely older civilization would’ve had to have mastered control over their aggression in order to survive, so they should be peaceful beings. Instead of inspiring fear, she hopes such a profound discovery would trivialize humans’ differences so they could see themselves as fellow Earthlings.

(Photo: TED / Asa Mathat)

SETI Institute, an interdisciplinary scientific organization that explores the nature of life throughout the universe, announced that starting today it will make large quantities of astronomical radio telescope data accessible to astronomers and other scientists as part of an effort to build a global community of searchers for evidence of extraterrestrial intelligence.

Today’s announcement represents the latest milestone in SETI Institute’s mission to facilitate mass collaboration in the search for civilizations beyond earth. The radio telescope data will be released by setiQuest, a program formed in 2009 after SETI Institute director Dr. Jill Tarter was awarded the 2009 TED Prize, whose benefits included $100,000 and the assistance of the global TED community to help realize her “One Wish to Change the World.” Accepting the prize, Dr. Tarter asked the TED community to “empower Earthlings everywhere to become active participants in the ultimate search for cosmic company.”

After months in development, the setiQuest program has reached the point where it is able to invite the global scientific community to access radio signal data collected by SETI Institute’s Allen Telescope Array (ATA). Commissioned in 2007, the Allen array is operated jointly by SETI Institute and the University of California at Berkeley. It is a “Large Number of Small Dishes” (LNSD) telescope array designed to conduct surveys for both conventional radio astronomy by the university, as well as for SETI Institute’s research.

SETI Institute analyzes the ATA radio data in real time with special software to detect technological signals from a distant extraterrestrial civilization. The process is analogous to listening to one hundred million radios, each tuned to a different channel and attached to an antenna that is highly sensitive to just one millionth of the sky, to find faint signals.

To date, SETI Institute’s methods have focused on the search for what are called narrowband signals. One of the benefits of opening the ATA data to the global scientific community is to invite development of techniques to analyze broadband signals.

The radio telescope data will be made available through setiQuest’s website, www.setiquest.org, in the form of files containing streams of data samples from specific targets in space. Data can be accessed by registered participants in the setiQuest program. SETI Institute hopes that by making the ATA data widely available, scientists around the world will develop new and innovative ways to process the massive quantities of radio signals streaming from space every second.

SETI Institute search programs have processed data in real time and discarded it shortly after the observation. They are capturing these new data sets to invite the public to expand the search. Now, setiQuest will provide a day’s worth of ATA data each week, and will leave the data on its website for up to six months.

While astronomers and specialists with experience in digital signal processing (DSP) may be the likely initial population of scientists and technologists with an interest in setiQuest, the program welcomes scientists and technologists of all disciplines. Those interested in learning how they can be part of the setiQuest project can find more information at http://www.setiQuest.org.

As part of making this wish come true, the SETI Institute is looking to hire a project manager with the experience, qualifications and energy to run the TED Prize wish project for at least two years. For the full job description and contact info, read on.

This is a unique opportunity to work in both open-source software and social media, on a project whose ramifications are literally beyond global.

Watch Jill Tarter’s TED Prize wish to get inspired:

We are seeking someone with deep experience in managing open-source software projects and the communities that power them to drive a bold and agenda-setting initiative. The initiative will involve managing a traditional open-source software project, as well as a complex public-facing system that will enlist the general/nontechnical public’s assistance in conducting our search. To succeed, a candidate above all needs a history of success in managing major open-source projects. While it’s not essential that this person be a coding engineer, it is essential that s/he be comfortable enough with C++ code to have technically meaningful interactions with committers and the broader open-source community. It’s also essential that s/he be a strong evangelist — able to speak inspiringly in public, and to energize, recruit and maintain engagement with key influencers in the open source coding world.

The other part of the job will be governing a project that will in many ways resemble Galaxy Zoo (an intriguing “citizen scientist” system). This will involve managing a respected Web development company as it creates the site, and thereafter overseeing/”gardening” a large community of nontechnical contributors. We expect this community to be self-policing and self-monitoring, like Wikipedia’s editorial community. But it will need leadership and a baseline architecture, and our hire will be responsible for delivering this.

This is a unique opportunity to work in both open-source software and social media, on a project whose ramifications are literally beyond global.

This will be a full-time role at the SETI Institute for two years, funded by the money TED has allocated toward granting Jill’s wish. However, because this is a TED Prize wish, one in which many people and individuals are giving a lot to make happen, we do hope to find someone who will do this at a reduced rate. We have a large brainstorm taking place on June 1 and would love to have the right person chosen and at the table for that meeting.

Please send a resume and cover letter to tedprize1@ted.com if you are interested in the position.

And please forward this opportunity on to anyone you believe possess the right skills!

“Around the World in 80 Telescopes” is a unique live 24-hour webcast, following night and day around the globe to some of the most advanced observatories both on and off the planet. You can watch it right here on the 100HA website, and on the 100HA channel on Ustream.tv.

The 24-hour webcast ends 4 April 2009, 09:00 UT (Universal Time/GMT). Both viewing channels are being hit heavily, so be patient, but the images are worth it. On right now: The Millimeter Array at NAOJ Nobeyama in Japan.

The Allen Telescope Array — an effort of the SETI Institute (along with the Radio Astronomy Laboratory at the University of California, Berkeley) — has its 20 minutes of fame tomorrow at 4:40 pm EDT (23:40 UTC). Jill Tarter says: “If you think big telescopes are cool, you can take a look now, or tune in live to see us observing with the ATA.”

Download a short video clip that introduces the ATA >>
Follow 100 Hours of Astronomy on Twitter >>

And watch Jill Tarter make her TED Prize wish to expand the ATA to search for alien intelligence:

Author and activist Isabel Allende discusses women, creativity, feminism — and the power of passionate thinkers and doers:

The former Finance Minister of Nigeria, Ngozi Okonjo-Iweala, talks about one key opportunity to grow African economies — by investing in women and the businesses they start:

(For more, watch Jacqueline Novogratz >>)

Scientist Nalini Nadkarni explores the world of the forest canopy — and shares her findings with the world below, through dance, art and bold partnerships. She’s working to inspire the next generation of women scientists:

The wonderful Nellie McKay sings “Mother of Pearl” (with the immortal first line “Feminists don’t have a sense of humor”) and “If I Had You” from her sparkling set at TED2008:

Find these four and many more astonishing women (including the legendary primatologist Jane Goodall, oceanographers Sylvia Earle and Tierney Thys, games theorist Brenda Laurel, Zipcar inventor Robin Chase … ) on TED.com >>

Astronomer Jill Tarter is director of the Center for SETI Research at the SETI Institute. She was awarded the TED Prize in 2009, and at the TED Conference she wished that the TED community would “empower Earthlings everywhere to become active participants in the ultimate search for cosmic company.” (Her talk on why the search for alien intelligence matters is now online.)

Yesterday the TED Blog interviewed Tarter over the phone about her TED Prize wish. She talked about some of the challenges and practicalities of SETI research, her new plans to help bring the world into the search for cosmic company, and a few new ideas about extraterrestrial intelligence that intrigue her. It’s a fascinating look at the pragmatic thinking that goes into this “stellar” project. Here’s a snippet:

If we could start out by recording data and having people develop algorithms for this class of signals in higher dimensions for us, then we could take the best algorithms and see if we can get them made efficient enough to run real time and put those on the telescope as well. And now you open up a whole universe of looking for something completely different — something we weren’t sensitive to before.

But what about the folks that don’t have that technological know-how? Can we get them involved too, if they’re passionate and eager to participate? Well, the eye is just a fabulous pattern-detection machine. It took a lot of years of evolution to make that work well. And so perhaps what we could do is involve people in using their eyeballs to find these complex signals.

Read the complete interview, below the fold >>

Transcript of interview with TED Prize-winner Jill Tarter of SETI (2/20/09):

You’ve said the Allen Telescope Array can augment the search for signals by orders of magnitude. Expand on that.

Right away, the Allen Telescope Array is almost a factor of 1,000 improvement of what we could do.

In the past, we’ve used other people’s telescopes for the real-time targeted searching. And if we’re lucky we get maybe five percent of their time. In theory, if we get this all working correctly, we can be on the air almost 100 percent of the time. We can do our SETI targeted searches at the same time that radio astronomers are doing their traditional astronomical surveys. So that’s a factor of 20.

We have the opportunity to build more back-end processing hardware and look at multiple stars at the same time. In the past, using the single-dish telescopes that we’ve used, you can only look one direction in the sky. Now, with an array built out of a lot of small telescopes, you look at a huge patch of the sky. You go from looking through a soda straw at a teeny piece of the sky to looking through a wide-angle camera. And in that piece of the sky there are many stars that I would like to look at.

I can actually build my equipment at the back end of the telescope such that it takes the data from all of the separate antennas and adds the signal together with different time delays and different phase shifts — it’s as if I were picking out up to eight individual pixels in this large field of view. I can look at up to eight different stars at the same time. So there was the factor of 20, and then there’s this other factor of eight.

And then I have another factor of almost 10 in terms of building more compute power to increase the amount of the spectrum that I can look at at any moment. So I can build more signal processing equipment. Hopefully for the first time we can do it with commodity servers in real time because until now we’ve built our own signal processing equipment. It looks like the industry has now made your standard cluster fast enough to do the signal processing. So all it means is, buying more of that, we can expand the bandwidth.

That’s what I can do in real time. Altogether, that’s at least a factor of 1,000.

What else is going to help augment the search?

I think about the other resources TED can potentially bring to the process — that is, getting the rest of the world involved, and not just doing the search with the equipment that we currently have in real time in Hat Creek.

There’s the idea of being able to record data, and having signal processing experts and open source developers around the world help us to build new algorithms. Because when I say if I put more compute power at the back end of this thing I can do more searching, I’m talking about the limited class of signals that we now look for in real time. And these are basically signals that are compressed in frequency. They’re narrow-band signals. They’re artifacts. They’re relatively easy to find. They’re certainly quite distinct from astrophysical signals. But there might be other classes of information-bearing signals. Information-rich encoded signals that will also propagate well through the interstellar medium.

We have not done much exploration of this class of signals because we haven’t had the compute power to go looking for them. But if we could start out by recording data and having people develop algorithms for this class of signals in higher dimensions for us, then we could take the best algorithms and see if we can get them made efficient enough to run real time and put those on the telescope as well. And now you open up a whole universe of looking for something completely different — something we weren’t sensitive to before. So I’m eager to do that, and ultimately we don’t know how this development process will work and whether the algorithms will ever be quite efficient enough to do in real time.

Hopefully, then, we’ve gotten smart people around the world and we’ve got them thinking about this search for more complex signals. But what about the folks that don’t have that technological know-how? Can we get them involved too, if they’re passionate and eager to participate? We thought, “Well, the eye is just a fabulous pattern-detection machine. A lot of years of evolution to make that work well.” And so perhaps what we could do is involve people in using their eyeballs to find these complex signals.

Crowd-sourcing.

Right. If we can push the technology and get a big enough data pipe in and out of the observatory, maybe that could actually impact the real-time observing so that people could see a pattern, compare it with known patterns of interfering signals that we’ve seen before, and impact the next observation that gets made. Say, “No algorithm found this yet, but I think there’s something there, and I think you ought to go back and follow up on it in the next observing path.” And we don’t know if that will work yet because there’s a lot of unknowns about how much data you can get in and out of this remote site. It’s a long way up I-5. Perhaps that’s too ambitious.

Perhaps the piece we’ll be able to do is sort through data offline and say, “Gee, there’s a pattern here. Gee, there’s a pattern there.” And act kind of like a human TiVo. So they could go through a lot of data and then build a new data set which is signal rich so that the developers wouldn’t be working on just the run-of-the-mill, raw, recorded data, but would have a set of recorded data that was chock full of complex patterns to try their algorithms on.

So, say I’m looking at this data, as one of your crowd-sourced eyeballs. What does the data look like? Something like static on a television screen?

If you’re working in the frequency and time dimensions looking for the kinds of signals that we’re now searching for, it would look like a snowy TV screen. In two dimensions, frequency, usually, we display horizontally, and time vertically. And then the kinds of signals that we look for now are straight lines through that two-dimensional slice. Narrow straight lines. And sometimes the lines are interrupted because they’re actually pulsed. They’re narrow-band pulses. And again, we’ve honed our skills to be pretty good, and our algorithms now can find that kind of artifact when your eye can no longer see it beneath the noise.

If you take the complex signals, the kinds of things that actually contain a lot of information, like what we generate today with our telcom, those algorithms can find that kind of signal if it’s really strong because enough bits and pieces of the signal in the frequency and time dimensions will put extra energy to some straight line somewhere that it will pull it up.

But usually the information and the energy in the signal was spread over other dimensions of chirp, repetition space, dispersion — all kinds of different ways you can encode signals. These are the higher dimensions I was talking about. And they become much more efficient for data transfer. When we use them on Earth, we have a particular encoding scheme, and the transmitter and the receiver both know what that scheme is, and you can build optimum detectors for any kind of signal. So the different schemes used for spacecraft communication or for cell phone technology are all different ways of putting information into the spectrum most effectively. And they wouldn’t look the same. When you looked at frequency and time, you might see absolutely nothing. But if you looked in other dimensions, you might actually see a pattern.

Are we talking about incidental signals or intentional, broadcast signals?

It’s always easier to find something that’s broadcast. If it’s incidental, there’s only enough power in it to serve the audience for which it’s intended. Our television transmitters leak out from the Earth. And actually, there’s a sphere surrounding the Earth from the earliest television signals, maybe 70 years ago, that’s going out one light year per year. But it’s really weak. Because we weren’t transmitting to anybody except to somebody in the next county. We weren’t trying to transmit to somebody at the next star. So the power involved is very small.

You can imagine that there have got to be economics of something for any technological civilization, some conserved resource that would probably mean that you don’t put any more power or energy into a transmission than is necessary. The chances are that what we are going to detect is going to be intentional, and it’s going to be attention-getting. But again, our definition of what is attention-getting — versus an advanced technologies definition of what is attention-getting — may not yet be the same. We’re a very young technology. Very primitive.

You can apply analysis to signals that are compressed in frequency, simply because astrophysics can’t do that. And if you find such a thing, you’ve either found someone else’s technology, or a new brand of astrophysics, a new field of astrophysics. But now that we’ve had more years of technology development, it might be that other kinds of signals make sense.

Is there a star, or a region in the sky, that intrigues you?

We know that life and technological civilizations arose and evolved around one particular type of star — a sort of medium-weight. It’s not really massive, and it’s not a tiny dwarf either. This kind of star burns stably for billions of years. We’re about halfway through the life of our star.

We don’t want to look at stars that are much more massive than the Sun because they use up their nuclear fuel in hundreds of millions of years and we don’t think you could get the evolution of a technological society that quickly. That’s a guess based on our example of one, and how long evolution as a natural process seems to take.

So the idea of looking for stars that are much lower mass than the Sun wasn’t in vogue for a long time because the idea was that those stars would be so faint that any habitable planet would have to be very, very close to the star and it would get tidally locked so that one face of the planet would continually face the star. You’d have a near side and a far side, or a hot side and a cold side. And we thought that it would be impossible to maintain any atmosphere in such a configuration.

But that was on the basis of early calculations, and we’ve now done more sophisticated calculations, and it looks like with a modest amount of greenhouse gas, you could retain an atmosphere and you could have circulation winds which would distribute the heat from the sub-solar point around to the backside. And you might end up with habitable parts of the planet at the terminator, halfway around the planet from the star.

And so, these M dwarfs that live forever — there’s no dwarf star like this that’s ever been born in the galaxy that has yet died. Their lives are tens of billions of years in length. They might, after a few billion years, become a reasonable place to host life. This is stuff we’re just beginning to study. Let’s just say that M dwarf stars are back on the table, whereas they were off for a while.

So, generally speaking, you’re searching for stars within certain parameters …

The kinds of stars that we’re interested in looking at are roughly the solar mass and smaller. And we’ll pick stars that are at least a couple of billions of years old to give evolution time to have produced a technology.

We’ll also pick stars for which companions — nearby stars — aren’t awkwardly placed, because stars that are too close to one another would tend to disrupt the planets in orbit around one of the stars. There are a couple of stable configurations. You can have two stars very close to one another and planets circling around the pair of stars. Or you can have two stars that are widely enough separated that the planets can be circling one and not be disrupted by the second. Or you can have stars that are essentially isolated, like our own sun. We’ll use that kind of thing as a criterion.

We’ll use what astronomers call the metallicity. For an astronomer, anything heavier than helium is a metal. If it’s known, we’ll use the ratio of the amount of iron to hydrogen in the star as an indicator of whether there’s enough stuff there to make rocky planets. Earlier generations of stars in the galaxy could well have had planets. But really, there was only hydrogen and helium to work with, so they’d all be gas giants and not small, rocky planets. It took several generations of star formation in the galaxy to build up the retinue of metals: carbon, nitrogen, oxygen, sulfur, phosphorus — stuff that we’re made out of — and the minerals that form a rocky planet that life as we know it enjoys.

We’ll also look at all of the stars that we know to have planetary systems because those are stars that are somewhat special and we know something more about them.

So we’re using a lot of biases here to pick out stars. At the moment we’ve got about a quarter of a million stars that roughly satisfy the criteria.

And outside of those biases?

We will also look in another way. We’ll say, “We’ve made a lot of assumptions. Why don’t we give up most of those assumptions, except the fact that a technological civilization is going to be associated with a stellar host.” And then the idea is to just look in the directions that there are huge numbers of stars, and not make these assumptions and biases and target individual stars. Just survey regions of the galaxy where the star density is a maximum. That’s generally toward the center of the galaxy and along the plane of the Milky Way galaxy toward the center.

We’ve picked out 20 square degrees on the sky that contain probably 10 billion stars. And we will survey those. And while we’re surveying that region of the sky, the astronomers will piggyback on our observing. And we’ll be piggybacking on theirs. Those stars are all mostly very far away. The galactic center is 26,000 light years away. Most of those stars are at such a large distance that any transmitter that is coming from there would have to be extremely strong.

But we don’t know that there aren’t these cosmic miracles.

Credit: TED.com / SETI Institute
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