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Fwd: Mysterious signals from 1000 light years away | New Scientist

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  • Frits Westra
    Mysterious signals from 1000 light years away http://www.newscientist.com/news/nographic.jsp?id=ns99996341 19:00 01 September 04 Exclusive from New Scientist
    Message 1 of 2 , Sep 3, 2004
      Mysterious signals from 1000 light years away

      http://www.newscientist.com/news/nographic.jsp?id=ns99996341

      19:00 01 September 04
      Exclusive from New Scientist Print Edition

      In February 2003, astronomers involved in the search for extraterrestrial
      intelligence (SETI) pointed the massive radio telescope in Arecibo, Puerto
      Rico, at around 200 sections of the sky.

      The same telescope had previously detected unexplained radio signals at
      least twice from each of these regions, and the astronomers were trying to
      reconfirm the findings. The team has now finished analysing the data, and
      all the signals seem to have disappeared. Except one, which has got
      stronger.

      This radio signal, now seen on three separate occasions, is an enigma. It
      could be generated by a previously unknown astronomical phenomenon. Or it
      could be something much more mundane, maybe an artefact of the telescope
      itself.

      But it also happens to be the best candidate yet for a contact by
      intelligent aliens in the nearly six-year history of the SETI@home
      project, which uses programs running as screensavers on millions of
      personal computers worldwide to sift through signals picked up by the
      Arecibo telescope.

      Absorb and emit

      “It’s the most interesting signal from SETI@home,” says Dan Werthimer, a
      radio astronomer at the University of California, Berkeley (UCB) and the
      chief scientist for SETI@home. “We’re not jumping up and down, but we are
      continuing to observe it.”

      Named SHGb02+14a, the signal has a frequency of about 1420 megahertz. This
      happens to be one of the main frequencies at which hydrogen, the most
      common element in the universe, readily absorbs and emits energy.

      Some astronomers have argued that extraterrestrials trying to advertise
      their presence would be likely to transmit at this frequency, and SETI
      researchers conventionally scan this part of the radio spectrum.

      SHGb02+14a seems to be coming from a point between the constellations
      Pisces and Aries, where there is no obvious star or planetary system
      within 1000 light years. And the transmission is very weak.

      “We are looking for something that screams out ‘artificial’,” says UCB
      researcher Eric Korpela, who completed the analysis of the signal in
      April. “This just doesn’t do that, but it could be because it is distant.”

      Unknown signature

      The telescope has only observed the signal for about a minute in total,
      which is not long enough for astronomers to analyse it thoroughly. But,
      Korpela thinks it unlikely SHGb02+14a is the result of any obvious radio
      interference or noise, and it does not bear the signature of any known
      astronomical object.

      That does not mean that only aliens could have produced it. “It may be a
      natural phenomenon of a previously undreamed-of kind like I stumbled
      over,” says Jocelyn Bell Burnell of the University of Bath, UK.

      It was Bell Burnell who in 1967 noticed a pulsed radio signal which the
      research team at the time thought was from extraterrestrials but which
      turned out to be the first ever sighting of a pulsar.

      There are other oddities. For instance, the signal’s frequency is drifting
      by between eight to 37 hertz per second. “The signal is moving rapidly in
      frequency and you would expect that to happen if you are looking at a
      transmitter on a planet that’s rotating very rapidly and where the
      civilisation is not correcting the transmission for the motion of the
      planet,” Korpela says.

      This does not, however, convince Paul Horowitz, a Harvard University
      astronomer who looks for alien signals using optical telescopes. He points
      out that the SETI@home software corrects for any drift in frequency.

      Fishy and puzzling

      The fact that the signal continues to drift after this correction is
      “fishy”, he says. “If [the aliens] are so smart, they’ll adjust their
      signal for their planet’s motion.”

      The relatively rapid drift of the signal is also puzzling for other
      reasons. A planet would have to be rotating nearly 40 times faster than
      Earth to have produced the observed drift; a transmitter on Earth would
      produce a signal with a drift of about 1.5 hertz per second.

      What is more, if telescopes are observing a signal that is drifting in
      frequency, then each time they look for it they should most likely
      encounter it at a slightly different frequency. But in the case of
      SHGb02+14a, every observation has first been made at 1420 megahertz,
      before it starts drifting. “It just boggles my mind,” Korpela says.

      The signal could be an artefact that, for some reason, always appears to
      be coming from the same point in the sky. The Arecibo telescope has a
      fixed dish reflector and scans the skies by changing the position of its
      receiver relative to the dish.

      When the receiver reaches a certain position, it might just be able to
      reflect waves from the ground onto the dish and then back to itself,
      making it seem as if the signal was coming from space.

      “Perhaps there is an object on the ground near the telescope emitting at
      about this frequency,” Korpela says. This could be confirmed by using a
      different telescope to listen for SHGb02+14a.

      Possible fraud

      There is also the possibility of fraud by someone hacking the SETI@home
      software to make it return evidence for an extraterrestrial transmission.
      However, SHGb02+14a was seen on two different occasions by different
      SETI@home users, and those calculations were confirmed by others.

      Then the signal was seen a third time by the SETI@home researchers. The
      unusual characteristics of the signal also make it unlikely that someone
      is playing a prank, Korpela says. “As I can’t think of any way to make a
      signal like this, I can’t think of any way to fake it.”

      David Anderson, director of SETI@home, remains sceptical but curious about
      the signal. ”It’s unlikely to be real but we will definitely be
      re-observing it.” Bell Burnell agrees that it is worth persisting with.
      “If they can see it four, five or six times it really begins to get
      exciting,” she says.

      It is already exciting for IT engineers Oliver Voelker of Logpoint in
      Nuremberg, Germany and Nate Collins of Farin and Associates in Madison,
      Wisconsin, who found the signal.

      Collins wonders how his bosses will react to company computers finding
      aliens. “I might have to explain a little further about just how much I
      was using [the computers],” he says.

      Eugenie Samuel Reich

      © Copyright Reed Business Information Ltd.
    • David Ocame
      Hello, please read on. The text below was excerted from an email received from Dr. H. Paul Schuch, Executive director of the SETILeagie, Inc. He has been in
      Message 2 of 2 , Sep 3, 2004
        Hello, please read on. The text below was excerted
        from an email received from Dr. H. Paul Schuch,
        Executive director of the SETILeagie, Inc. He has been
        in contact with the scientists who received the
        signal. Here is what he has to say:

        Here is the text of an email received today
        from SEI@home director Dan Werthimer of U.C. Berkeley
        (and now in
        Arecibo):


        >it's a zero on the rio scale.

        >none of our candidates are very interesting - they
        are all
        consisitent with noise. we will continue to observe
        many
        of the candidates over the next few years, but there's
        nothing on the candidate lists we are particularly
        excited about.

        >a reporter from new scientist read the seti@home web
        pages:
        in particular there's a section on "candidate signals"
        where
        we discuss how we score signals and we show the data
        from
        the 220 candidates we re-observed at arecibo 1.5 years
        ago.
        these web pages are old, but the reporter made an
        exciting
        story about them, by exagerating their content and
        mis-quoting
        us and quoting us out of context, and making a press
        release
        about one of the candidates that has a bit higher
        score than
        the others.

        >i talked to a couple of reporters today, explaining
        we've seen
        stuff like this for the last 30 years, and it's always
        turned
        out to be rfi or noise, and that there's nothing to
        get excited
        about, and that when you look at 50 trillion bytes of
        data,
        occasionally you'll find patterns that look unusual
        just from
        noise...

        >i wish we had something in our data to get excited
        about.

        >tomorrow we'll start using the multibeam receiver
        you guys made
        to map HI in the galaxy. the HI survey will take
        about five years.
        we begin in 12 hours.

        >best wishes from arecibo,

        >dan



        The Rio Scale to which Dan refers is a one-to-ten tool
        SETI scientists
        use for quantifying the importance of a candidate
        detection. For
        details, see
        <http://www.setileague.org/iaaseti/rioscale.htm>.

        Yours for SETI success,
        Dr. H. Paul Schuch




        Don't believe everything you read or hear from
        reporters. Their main interest is that you buy their
        newspapers or hear their sponsors ads!

        David Ocame






        =====
        ***********************************
        ***********************************

        Dave Ocame, N1YVV

        East Shore Park Observatory
        FN31ng
        -72.53856 longitude
        41.16797 latitude
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