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New Worlds Targeted by Allen Telescope Array

The on-again, off-again SETI search at the Allen Telescope Array is back in business as Jill Tarter and team focus in on some of the more interesting worlds uncovered by the Kepler space telescope and follow-up observations. You’ll recall that last April the ATA was in hibernation, having lost its funding from the University of California at Berkeley, which had operated the Hat Creek Observatory in northern California where the ATA is located. It took a public campaign to raise the funds needed for reactivation and new operations, as well as help from the US Air Force in the form of its own assessment of the ATA’s applicability in its space situational awareness studies, which include developing a catalog of orbiting space objects.

The SETI Institute, along with third-party partners and volunteers, has set up SETIstars.org as a fund-raising operation specifically targeting the ATA — it’s important to realize that getting the array back in operation is a first step in the larger process of meeting expenses for continuing work, so you’ll want to check in on SETIstars regularly to see how the campaign is going.

But back to the forthcoming ATA work on Kepler planets. The plan is to work through the Kepler discoveries, taking advantage of the fact that SETI now knows for a fact that the stars in question have planets. Thus Jill Tarter (SETI Institute):

“This is a superb opportunity for SETI observations. For the first time, we can point our telescopes at stars, and know that those stars actually host planetary systems – including at least one that begins to approximate an Earth analog in the habitable zone around its host star. That’s the type of world that might be home to a civilization capable of building radio transmitters.”

The worlds found in the habitable zone (here defined as the zone in which liquid water could exist on the surface) will receive priority, but the people behind the ATA are as aware of the dangers of preconceived notions as any of us, and if sufficient funding is found, all the planetary systems Kepler discovers will be examined across the 1 to 10 GHz terrestrial microwave window. The ATA’s ability to search across tens of millions of channels simultaneously gives it capabilities far beyond those of more common SETI work in limited frequency ranges.

Planets Around Massive Stars

Meanwhile, the Kepler Science Conference continues, with the program available online. And I don’t want to get deep into the Kepler conference without getting to the recent work at Caltech, where astronomers announced the discovery of 18 planets around stars more massive than the Sun. This work involved the Keck Observatory in Hawaii with follow-up work at McDonald and Fairborn Observatories (Texas and Arizona), focusing on ‘retired’ A-class stars more than one and one-half times as massive as the Sun. These so-called ‘retired’ stars are now in the process of becoming sub-giants. The planets were detected by radial velocity methods.

The planets here all have masses similar to Jupiter’s and represent a 50 percent increase in the number of planets known to be orbiting massive stars. What’s particularly interesting here is the wider orbits in which these planets are found. All are at least 0.7 AU from their stars, while a sample of 18 planets around stars like the Sun would turn up at least half of them in close orbits, the result of planetary migration. John Johnson (Caltech), first author of the paper on this work, says the question is whether gas giants around massive stars do not migrate in the first place, or whether they do migrate but are simply destroyed when they plunge into their stars. Also interesting is the fact that the orbits of these planets are primarily circular, while planets around Sun-like stars vary from elliptical to circular.

The authors see the new planets as further evidence supporting the core accretion model of planet formation, in which planets grow through the accumulation of small objects to ‘snowball’ into the resulting world. Stellar mass seems to be a crucial factor, which would not necessarily be the case with the gravitational instability model, in which knots of matter in the circumstellar disk collapse rapidly to form a planet.

From the paper:

[The] observed correlations between stellar properties and giant planet occurrence provide strong constraints for theories of planet formation. Any successful formation mechanism must not only describe the formation of the planets in our Solar System, but must also account for the ways in which planet occurrence varies with stellar mass and chemical composition. The link between planet occurrence and stellar properties may be related to the relationship between stars and their natal circumstellar disks. More massive, metal-rich stars likely had more massive, dust-enriched protoplanetary disks that more efficiently form embryonic solid cores that in turn sweep up gas, resulting in the gas giants detected today.

The paper is Johnson et al., “Retired A stars and their companions VII. Eighteen new Jovian planets,” accepted by the Astrophysical Journal (preprint).

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Comments on this entry are closed.

  • Eric December 8, 2011, 5:14

    Targeting the Kepler planets/planetary candidates seems gimmicky to me. Why don’t they take the Benfords’ advice and target the Galactic Core?

  • Mike December 8, 2011, 9:53

    To Eric, I suppose targeting the Galactic central region might be a far more effective search strategy but when you’re forced to raise money by a public fund drive you may need to resort to gimmicks. Oh well, at least the ATA is being used and not left to rot.

  • ljk December 8, 2011, 10:10

    Eric said on December 8, 2011 at 5:14:

    “Targeting the Kepler planets/planetary candidates seems gimmicky to me. Why don’t they take the Benfords’ advice and target the Galactic Core?”

    Exactly, Eric. They are playing it safe and traditional – I would even go so far as to say they are making an almost token effort, perhaps so as not to worry their current benefactors who may not be aware of or appreciate the strides and expanded knowledge made in the SETI field since it began officially over fifty years ago.

    I am not against looking at G class suns with Earth-type exoworlds, but if they really want a chance to find about the only kind of ETI we can detect at this stage of human technology and effort, we need to investigate other regions of the electromagnetic spectrum in addition to radio and in places such as celestial objects which appear only in the infrared.

    http://blogs.discovermagazine.com/cosmicvariance/2008/12/02/no-dyson-spheres-found-yet/

    http://home.fnal.gov/~carrigan/infrared_astronomy/Fermilab_search.htm

    The one thing SETI has taught us since Frank Drake conducted Project OZMA in 1960 is that either there is no sophisticated and voluminous dialogue between worlds in at least our part of the galaxy, or they are exchanging information via methods we either have not investigated or are currently unaware of.

    This is why we need to do much more to get out of the radio/Earthlike SETI paradigm, especially since the beings we hope to find are supposedly much more sophisticated than humanity. This is why Optical (laser, infrared) SETI did not swing into gear until the late 1990s despite being first promoted right around the time of Radio SETI because the ones running mainstream SETI thought it would not work because humans c0uld not send out powerful laser beams among other things.

    See here for the details of Optical SETI’s historical struggles to become accepted by the mainstream community and how it should serve as an example for other methods of detecting intelligent alien beings:

    http://www.coseti.org/mileston.htm

  • Eniac December 9, 2011, 0:47

    Isn’t optical SETI problematic because any signal would get lost in the solar/stellar glare?

    To me it seems the most economical and sustainable way to send a signal would be a vast phased array of millions or billions of small and simple transmitters flying in formation close to the sun where there is energy, but using some part of the radio or microwave spectrum where the sun is relatively silent. What would be needed to maintain such an array forever would be a steady stream of replacement elements from an indefinitely self-maintaining factory of some sort, perhaps based on Mercury where there are practically inexhaustible energy and material resources.

    I have serious problems with the proposition that we can set up a “funeral-pyre”, but at the same time not avoid our own demise. If there is going to be a demise, I would think it would have to be catastrophic and be forced on us against our will. There will be very little time and resources for building a monument: we will be too busy trying to save ourselves.

  • ljk December 9, 2011, 9:20

    Since the ATA was supposed to devote a fair amount of time to non-SETI astronomical observations, I am surprised that other universities haven’t jumped on that bandwagon – or is there some kind of political issue where only Berkeley is allowed to use it? Or is it just the case of tight budgets all around?

    Maybe we have another answer to the Fermi Paradox: Cultures do not consider astronomy and SETI a high enough priority to support properly, thus they are neither searching nor sending.

  • ljk December 9, 2011, 11:06

    Eniac said on December 9, 2011 at 0:47:

    “Isn’t optical SETI problematic because any signal would get lost in the solar/stellar glare?”

    Please check out this Web site which has loads of information on Optical SETI going back to Charles Townes advocacy of this method in 1960 (he invented the laser, by the way):

    http://www.coseti.org/

    Here you will find how and why a powerful laser can outshine a star, carry lots more information than radio (including video), how even serious amateurs can conduct Optical SETI, and why they won’t need to sift through millions of channels like radio to find the artificial ones.

    Radio broadcasts do have the advantage of being cheaper and easier to produce, plus it can be spread out over a wide area of the galaxy. However, sophisticated societies may want to use something more advanced. Plus, if we do get an Optical METI, it will be a message deliberately meant for us and not some random signal.

    FYI – Did you know that even Albert Einstein was advocating a form of Optical SETI in 1937? He suggested that any intelligent beings on Mars might use light beams to signal Earth.

  • Eniac December 10, 2011, 12:48

    Here (http://seti.harvard.edu/oseti/) it says:

    A high-intensity pulsed laser, teamed with a moderate sized telescope, forms an efficient interstellar beacon. Using only “Earth 2000” technology, we could build such a laser transmitter. To a distant observer in the direction of its slender beam, it would appear (during its brief pulse) a thousand times brighter than our sun.

    This is very exciting. If the beacon can really appear one thousand times brighter than the sun, it should be observable further than the stars themselves, i.e. all the way across the galaxy and even in neighboring galaxies. (Or not? Perhaps not enough photons due to the short pulse duration?)

    This compares favorably with radio signals, which, it has been said, become undetectable a relatively short distance out.

  • Duncan Ivry December 10, 2011, 16:11

    ljk: “Cultures do not consider astronomy and SETI a high enough priority to support properly, thus they are neither searching nor sending.”

    Above politics and tight budgets, there are so many other interesting things, that those singular beings who do science in such a culture might just personally prefer to work on research topics different from astronomy, or inside astronomy different from SETI. Answers to the Fermi paradox don’t necessarily have to be those big ones usually mentioned.

  • Keith Cooper December 12, 2011, 8:57

    But the ATA has also been doing a galactic centre survey:
    http://www.seti.org/seti-institute/project/details/seti-ata-galactic-center-survey

    @ljk: I believe UC Berkeley co-own or at least co-manage the ATA, so that’s probably why they get a lot of time on it. Have no idea about other universities but I’m sure if they had the money they would also be using it.

    We can criticise SETI on many things, but I think some of the criticism here is unfair. Many SETI scientists agree that optical or infrared SETI is a really strong contender, but unlike radio SETI there is no way of covering a large area of sky at once at those nanosecond timescales – you’ve got to search each star one at a time, which slows the process down. Plus time on optical telescopes is in high demand. Until the technology comes along to essentially take snapshots of the sky looking for nanosecond bursts, optical SETI is going to be slow. A network of amateur telescopes would work better – sort of like an optical version of Paul Shuch’s Project Argus, but when the SETI Institute approached CCD manufacturers to build the type of photomultipliers that would be needed, they couldn’t get a quote cheap enough that would entice amateurs to hand over the cash and take part. And for infrared SETI, we would have to go into space.

    Regarding the Kepler candidate search being conducted by the ATA (and previously by Dan Werthimer et al at Green Bank earlier this year) – targeted searches spend more time on their targets and listen a lot more closely to their stars and attendant planets than an overall galactic centre survey would. There’s that statistic that is frequently quoted, that SETI has only searched a thousand or so stars in depth in the past 50 years. Of course there have been many searches of wide areas of the sky, but those do not look as closely at individual stars. I know how Seth Shostak likes to talk about how processing power is increasing with Moore’s Law, which will allow more intense targeted searches in the future, but it is only going to happen if SETI gets the money.

    Besides, one of the main aims of the Kepler mission is to find potentially habitable worlds, so we might as well search them. Although I do wonder whether they should wait until these candidates are confirmed.

  • ljk December 13, 2011, 9:42

    I think searching for other life in the Universe, especially intelligent life, is one of the most important things our species can and should do. I am glad to be living at a time when it can be undertaken with some real scientific and technological ability.

    We now have over seven billion humans on this planet. Surely a few more can be devoted to this effort. We do have the money and resources for a serious SETI effort, if we so choose. Fifty years after the start of the modern SETI era, we can and should be doing a lot better than we have until recent years. This is NOT a reflection or comment on those who have dedicated time, energy, resources, and money to SETI, but to society at large to make more of a real effort in this goal.

  • ljk January 6, 2012, 21:37

    Kepler’s SETI Project Detects First Signals Analysis

    by Ian O’Neill

    Fri Jan 6, 2012 02:34 PM ET

    In an effort to detect the radio emissions from a hypothetical extraterrestrial intelligence, it helps to know where to look. Space, after all, is a very big place and the chances of accidentally stumbling across an alien television signal is very low.

    So, using data from the Kepler space telescope, astronomers are becoming more focused on “listening” for radio signals coming from stars known (or at least thought) to have planets orbiting them. And it seems the first “candidate” signals have been detected!

    But before you start popping the “we’ve discovered ET!” champagne corks, this first signal is most likely terrestrial in origin.

    “We’ve started searching our Kepler SETI observations and our analyses have generated some of our first candidate signals,” scientists of the University of California, Berkeley announced on Friday.

    Full article here:

    http://news.discovery.com/space/is-there-a-seti-signal-coming-from-a-kepler-exoplanet-120106.html

  • ljk January 10, 2012, 23:33

    No, SETI has not detected an alien signal from a Kepler planet

    By Phil Plait, the Bad Astronomer

    Last night, I started getting emails and tweets asking about a possible detection of a radio signal coming from two of the newly-discovered planets orbiting other stars.

    Cutting to the chase: yes, a signal has been seen, but no, it’s not coming from some alien civilization. It’s almost certainly something much closer, like a satellite interfering with the observation.

    So what’s the deal?

    Full article here:

    http://blogs.discovermagazine.com/badastronomy/2012/01/06/no-seti-has-not-detected-an-alien-signal-from-a-kepler-planet/

  • ljk May 4, 2012, 1:55

    Strapped for cash, humanity’s biggest SETI effort so far now has to look for space junk for the USAF:

    http://www.space.com/15479-seti-telescope-space-junk-search.html

    There’s more to blame here than just the bad economy.

  • ljk May 22, 2012, 15:24

    http://www.seti.org/node/1281

    SETI Institute Celebrates World-Famous Alien Hunter’s 35 Years of Research And Looks Forward To The Next ChapterSupport SETI Research

    For Immediate Release May 22, 2012

    Contact:
    Curtis Sparrer
    Grayling Connecting Point
    curtis.sparrer@graylingcp.com
    Work: 415-442-4034
    Cell: 713-240-0485

    Karen Randall
    SETI Institute
    krandall@seti.org
    Work: 650-960-4537

    SETI Institute Celebrates World-Famous Alien Hunter’s 35 Years of Research And Looks Forward To The Next Chapter

    Astronomer who inspired Jodie Foster’s character in “Contact” retires as Director of the Center for SETI Research

    Astronauts, Scientists and Celebrities to gather in Santa Clara to salute science, imagination, and Tarter June 22 – 24

    Mountain View, California – After thirty-five years of searching the skies for signs of intelligence beyond Earth, astronomer Jill Tarter is turning over the research reins to new leadership at the non-profit SETI Institute. SETI Institute Physicist Gerry Harp will succeed Tarter as Director of Center for SETI Research while Tarter will focus her time on fundraising for this work as the Bernard M. Oliver Chair for SETI within the scientific organization.

    “For many years working at the SETI Institute I’ve worn two hats: the Bernard Oliver chair, and the Director of the Center for SETI Research,” said Tarter, who was a prototype for the character Ellie Arroway in Carl Sagan’s novel and film “Contact.” “My colleague Dr. Gerry Harp will step into the directorship role to continue our strong tradition of excellent research, freeing me up to focus on finding stable funding for it. I want to make the endowment of SETI research a success, so that my colleagues now, and in the future, can focus on the search for extraterrestrial intelligence for all of us.”

    The SETI Institute is celebrating Tarter’s career at the upcoming SETIcon II, June 22-24 in Silicon Valley at the Santa Clara Hyatt. SETIcon II is a public convention that draws together more than 60 scientists, artists and entertainers to explore our place in space and the future of the search for life in the universe through presentations, panels, exhibits and films. Tarter will be celebrated at a gala event on Saturday evening, June 23. Speakers include astronaut Mae Jemison, astronomer and “Drake Equation” author Frank Drake, and “Star Trek” actor Robert Picardo.

    Tickets are available now at http://seticon.org/

    Tarter, 68, signed on to the NASA SETI program in the 1970s when a small group of NASA researchers were developing novel equipment and strategies to make systematic radio SETI observations. Since the demise of that program by Congressional fiat in 1993, she has led the efforts at the non-profit SETI Institute to continue the work.

    Tarter spearheaded a decade-long program, dubbed Project Phoenix, that used large antennas in Australia, Puerto Rico and West Virginia to examine approximately one thousand nearby star systems over an unprecedented wide range of radio frequencies.

    Astronomers suspected that planets existed around other stars, but that was only a hypothesis – until 1995. Recently NASA’s Kepler telescope, launched in 2009, has discovered thousands of new planetary systems, some of them containing planets as small as the Earth.

    “Kepler has been a paradigm shift—starting with the first data release in 2010 and second in 2011 and third in 2012, we have altered our SETI search strategy. We are no longer pointing our telescopes at Sun-like stars in hopes of finding something; we are now observing stars where we KNOW there are planets. Exoplanets are real. We’ve gone from having 20-30 potential targets to having thousands of targets. Kepler is telling us WHERE to look, and we are focusing there,” said Tarter.

    [Yes, but are any of those Kepler exoplanets capable of supporting even basic life? We have not found an Earthlike one yet and as for exomoons, we still haven’t found any and only a relative few known exoplanets of Jupiter stature are in orbits considered “safe” for life. As I said in this thread earlier, they are playing it safe, which means SETI is going to take even longer to find a real artificial signal of alien origin. Of course I understand why The SETI Institute is focusing on exoplanets: They exist. They can be pointed to. ETI, on the other hand, have yet to be found and their possibilities are so varied, including the possibility that they do not exist at all. No one wants to risk millions in funding on an unsure possibility. – LJK]

    Kepler planet-hunters are key presenters at SETIcon II. Dr. Geoff Marcy (UC Berkeley), Debra Ann Fischer (Yale University), Jon Jenkins and Doug Caldwell (Kepler Mission and SETI Institute) will be sharing the excitement of discovering exoplanets.

    “SETI research experiments are funded by private donations, limiting how quickly we can search these newly discovered planets for intelligent life,” said Tarter.

    “The best reason to support SETI research is because it is an investment in our own future. The scientist Phil Morrison said that ‘SETI is the archeology of the future.’

    Think about it. If we detect a signal, we could learn about THEIR past (because of the time their signal took to reach us) and the possibility of OUR future. Successful detection means that, on average, technologies last for a long time. That’s the only way another technological civilization can overlap with us in time and space.

    Understanding that it is possible to find solutions to our terrestrial problems and to become a very old civilization, because someone else has managed to do just that, is hugely important! Knowing that there can be a future may motivate us to achieve it.”

    Hope to see you all at SETIcon! Register now at http://seticon.org/

  • ljk July 27, 2012, 2:01

    New Frontiers in SETI Research

    Gerry Harp, who has taken over Jill Tarter’s job as research director at the SETI Institute, has high hopes for the hunt for alien life

    By Rachel Courtland / July 2012

    23 July 2012—In 1960, astronomer Frank Drake pointed a single radio dish at two nearby stars to hunt for signals from extraterrestrial civilizations. Since then, the search has gotten considerably more high-tech. Among those leading the charge is IEEE Member Gerry Harp, who in May took over as director of research at the SETI Institute, a position most recently held by famed signal hunter Jill Tarter. IEEE Spectrum Associate Editor Rachel Courtland talked to Harp about the track record of SETI (Search for Extraterrestrial Intelligence) so far and what can be done to improve the search.

    IEEE Spectrum: The Allen Telescope Array is the only telescope designed specifically to search for signals made by an extraterrestrial intelligence. How does it work?

    Gerry Harp: The Allen Telescope Array is not a single-dish telescope. It actually has 42 dishes that each make a measurement of the electric field arriving from space. We take signals from all 42 dishes and add them together with the appropriate coefficients to make an instantaneous snapshot of a very large field of view on the sky.

    Because it’s an interferometer, it’s possible to take the signals from each antenna and split those signals, say, three different ways, and then phase them up at three different points on the sky so we can get three different pointings at once. That speeds up our search by a factor of three. But it also gives us a special benefit of anticoincidence RFI detection. RFI is radio frequency interference. We find lots and lots of artificial signals every day, but almost all of them are human made—so far all of them, as far as we know.

    If we see a signal in one beam, and we find the signal in another beam pointed in another direction, then we know that signal must be coming from Earth. We have a lot of bright sources. We have all the geosynchronous satellites up in space, which number in the hundreds, and then all the low earth orbiting satellites that number in the thousands. If any one of those appears close to our field of view, it can generate interference. But interference is never local; it’s always a wash across the image, so we can tell by this three-beam method if something is really coming from far away.

    IEEE Spectrum: What exactly are you looking for?

    Gerry Harp: The typical signal [we’re searching for] is a very, very narrow band signal—we’re talking about 1 hertz wide. There’s all sorts of reasons why that seems like a good choice, not the least of which is that there’s no natural signal that is as narrow as 1 Hz. So if we find such a signal arriving from outer space, it’s either E.T. or it’s a very interesting astrophysical artifact.

    It’s always been, from the very start, a guessing game. At the very beginning, Frank Drake made the guess that they would be sending us a very narrow band signal. That was a good guess, and it turns out that subsequent science supported that guess. But more recent developments in technology have called that guess into question, and now we have to ask, “Well, what other ways might they be sending us signals, and how shall we look for them?” We have to develop algorithms to find that stuff, and it’s a very challenging problem.

    Full interview here:

    http://spectrum.ieee.org/aerospace/astrophysics/new-frontiers-in-seti-research

  • ljk August 8, 2012, 12:27

    How Jill Tarter got to be head of The SETI Institute:

    http://io9.com/jill-tarter/

  • ljk August 8, 2012, 12:44

    A radio interview from August 2, 2012 with Jill Tarter online here:

    http://kalw.org/post/looking-setis-jill-tarter-her-search-extraterrestrial-life

  • ljk November 28, 2012, 14:11

    http://arxiv.org/abs/1210.8246

    Primary Beam and Dish Surface Characterization at the Allen Telescope Array by Radio Holography

    Authors: ATA GROUP: Shannon Atkinson, D. C. Backer, P. R. Backus, William Barott, Amber Bauermeister, Leo Blitz, D. C.-J. Bock, Geoffrey C. Bower, Tucker Bradford, Calvin Cheng, Steve Croft, Matt Dexter, John Dreher, Greg Engargiola, Ed Fields, Carl Heiles, Tamara Helfer, Jane Jordan, Susan Jorgensen, Tom Kilsdonk, Colby Gutierrez-Kraybill, Garrett Keating, Casey Law, John Lugten, D. H. E. MacMahon, Peter McMahon, Oren Milgrome, Andrew Siemion, Ken Smolek, Douglas Thornton, Tom Pierson, Karen Randall, John Ross, Seth Shostak, J. C. Tarter, Lynn Urry, Dan Werthimer, Peter K. G. Williams, David Whysong (ATA GROUP), G. R. Harp, R. F. Ackermann, Z. J. Nadler, Samantha K. Blair, M. M. Davis, M. C. H. Wright, J. R. Forster, D. R. DeBoer, W. J. Welch

    (Submitted on 31 Oct 2012)

    Abstract: The Allen Telescope Array (ATA) is a cm-wave interferometer in California, comprising 42 antenna elements with 6-m diameter dishes. We characterize the antenna optical accuracy using two-antenna interferometry and radio holography. The distortion of each telescope relative to the average is small, with RMS differences of 1 percent of beam peak value.

    Holography provides images of dish illumination pattern, allowing characterization of as-built mirror surfaces. The ATA dishes can experience mm-scale distortions across -2 meter lengths due to mounting stresses or solar radiation. Experimental RMS errors are 0.7 mm at night and 3 mm under worst case solar illumination. For frequencies 4, 10, and 15 GHz, the nighttime values indicate sensitivity losses of 1, 10 and 20 percent, respectively.

    The ATA.s exceptional wide-bandwidth permits observations over a continuous range 0.5 to 11.2 GHz, and future retrofits may increase this range to 15 GHz. Beam patterns show a slowly varying focus frequency dependence.

    We probe the antenna optical gain and beam pattern stability as a function of focus and observation frequency, concluding that ATA can produce high fidelity images over a decade of simultaneous observation frequencies.

    In the day, the antenna sensitivity and pointing accuracy are affected. We find that at frequencies greater than 5 GHz, daytime observations greater than 5 GHz will suffer some sensitivity loss and it may be necessary to make antenna pointing corrections on a 1 to 2 hourly basis.

    Comments: 19 pages, 23 figures, 3 tables, Authors indicated by an double dagger ({\ddag}) are affiliated with the SETI Institute, Mountain View, CA 95070. Authors indicated by a section break ({\S}) are affiliated with the Hat Creek Radio Observatory and/or the Radio Astronomy Laboratory, both affiliated with the University of California Berkeley, Berkeley CA

    Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)

    Cite as: arXiv:1210.8246 [astro-ph.IM]
    (or arXiv:1210.8246v1 [astro-ph.IM] for this version)

    Submission history

    From: Gerald Harp Ph.D. [view email]

    [v1] Wed, 31 Oct 2012 07:19:49 GMT (1937kb)

    http://arxiv.org/ftp/arxiv/papers/1210/1210.8246.pdf

  • ljk January 3, 2013, 17:57

    http://www.aps.org/publications/apsnews/201301/profilesjan2013.cfm

    Profiles in VersatilityLeading the Search to Find ET is No Gamble to this Physicist

    By Alaina G. Levine

    Gerry Harp hates the film “The Day the Earth Stood Still.” The physicist, who took over the reins of the SETI Institute in July 2012 from its longtime leader Jill Tarter, thinks the movie about aliens attacking Earth doesn’t do much to enhance the reputation of the beings he is hoping his team will find. But he views part of his role, as Director of the Center for SETI Research, as playing PR Rep for both the Institute and its potential extraterrestrial collaborators.

    “We haven’t done a good enough job of getting the word out about the science behind SETI,” Harp acknowledges. “SETI has a hard enough time getting respect in the public,” let alone the scientific community. “There’s a reputation aspect. It’s undeniably true.”

    Part of the challenge, he notes, is that SETI, whose mission is “to explore, understand and explain the origin, nature and prevalence of life in the universe,” is too often considered to be a research and career gamble.
    “Ask undergraduates if they want to join SETI and they answer in the affirmative,” he explains. But towards the end of college, if you inquire again, they’ll say no, he says, because they view SETI science as potentially “high risk,” and they think “if we don’t find the signal in my career, my career will go nowhere.”

    But “this endeavor is not as long a shot as people think,” he says. “The technology is growing exponentially, especially signal processing, as computers are getting faster. Every six years our search speed is increased by a factor of 10. It’s not like we’re looking at star after star after star at the same rate.” As the telescopes have improved, so has their ability to find new worlds which may be candidates for inhabitability of some form of life. Currently, many hundreds of exoplanets have been confirmed. And yet, “even though we’re experiencing all this exponential improvement, we’re looking at billions of star frequencies at one time,” he notes. “There are so many stars in the galaxy, that that is a drop in the bucket, equivalent to one cup of water from the ocean.”

    SETI does have its fans among the lay community. Over 240,000 of them follow the Institute on Twitter. “SETI is a very interesting topic for the US public at large,” he says. “We have an overwhelmingly large number of people who think this research should be pursued.”

    Harp didn’t begin his career with extraterrestrial aspirations. As a physics graduate student at the University of Wisconsin-Milwaukee, he specialized in quantum mechanics, and in particular electron holography. He invented a new type of photoelectron microscope and composed new computational methods able to provide 3D images of atoms. After he graduated in 1991, he soon found a tenure-track position at Ohio University where he stayed for six years.

    It wasn’t until 2000 that Harp joined SETI, initially as a Senior Software Scientist, and later as a Senior Astrophysicist. He realized that the work he had done as a doctoral student could be applied in astronomy to look for alien signals in new ways. “The difference between a hologram and a regular photograph is that holography preserves information about the particles’ (electrons’ or photons’) direction of arrival at the photographic plate,” he explains. “In radio astronomy, this direction of arrival information (encoded as the signal’s phase) can be directly digitized from the radio antenna.” His research led to a technological breakthrough in which the Allen Telescope Array (ATA), the principle SETI observatory, could detect noise coming from Earth and use something like holography to determine the direction from which a signal arrives and rule out potential signals that are not coming from space.

    Now, as Director, he plans to implement new techniques that will “greatly enhance the number of different signal types we can be sensitive to, including conventional carrier waves (think, AM radio) as well as various wide-bandwidth signals like those used for satellite communication on Earth,” he says. “We shall test for literally billions of signal types never probed before.”

    Harp hopes to attract more talented scholars to SETI. “We find the best people to bring in are mid-career scientists who have already established themselves,” he says. Given all the technical enhancements, this is a great time to step up recruitment, he indicates. He is furthermore encouraging more publications relating to SETI research. “SETI scientists should be writing more papers and getting the kind of attribution they deserve,” he says.

    This PR push is vitally important given their uphill battle. “We once thought there was a possibility of civilization around every star,” notes the physicist. “Now we can say no–life is rare, even bacteria…As we gain more and more knowledge about ourselves, we realize how special we are compared to the rest of the universe.”

    Yet he is optimistic. “If I had to bet, intellectual extraterrestrial life is in this galaxy. It’s way too big for it not to be.” Moreover, “they won’t look like humans. [But] their radio technology will be similar to ours because the physics is the same.”

    Alaina G. Levine is a science writer and President of Quantum Success Solutions, a science career and professional development consulting enterprise. She can be contacted through http://www.alainalevine.com.© 2012, Alaina G. Levine

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