archiv~1: SETI Pure tones ? (long)

SETI Pure tones ? (long)

E. Piotelat ( (no email) )
Fri, 06 Nov 1998 10:38:18 +0100

Hi SETIzen,

I would like to know your opinion about the "pure sounds" (see Sunday Time
article bellow, transmitted by JP Pharabod)

Did the SETI League telescopes allready find such signals ?

Thanks & Regards

Elisabeth
http://www.chez.com/telescope/seti/


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> Sunday Times of London,
> by Steve Farrar & Alex McGregor,
> 7 June 1998
>
> Some of the world's leading astronomers revealed last week that
> they have collected more than 100 unexplained radio signals
> during routine surveillance of space.
>
> These faint, pure tones have no natural origin and could have
> been created artificially, the scientists said. They do not rule
> out the astonishing possibility that this strange radio traffic
> could have extra-terrestrial origins.
>
> Most of the signals have been picked up by American radio
> telescopes managed by the Search for Extra-Terrestrial
> Intelligence Institute (SETI) in Mountain View, California, set
> up in 1988 to study radio static in space and scan it for
> material that could be evidence of alien contact. A few have
> also been logged by British astronomers studying stars and
> galaxies with the Lovell telescope at Jodrell Bank, near
> Macclesfield in Cheshire.
>
> "It's tempting to hypothesise that at least some of these
> seductive signals were truly from ET and that they vanished from
> the ether when the extra-terrestrials turned off their
> transmitters or otherwise went off air before we could verify
> the message," said Dr Seth Shostak, SETI's public programmes
> scientist.
>
> Alternatively, he said, it was possible they were simply the
> product of some kind of local interference that did not repeat
> when the astronomers tried to relocate the rogue signals.
>
> SETI, which was formed by scientists including Carl Sagan and
> received funding from Nasa until 1993, has yet to discover any
> clear, repeated radio pattern that might hint at the existence
> of alien intelligence in the universe.
>
> The short, indistinct signals that have been detected are a far
> cry from the resounding pulses featured in the movie Contact, in
> which Jodie Foster played a SETI astronomer who deciphered radio
> contact with aliens. Foster's signed photograph is pinned to a
> wall in SETI's Silicon Valley office. None of the signals has
> been heard by human ears - they were all picked up by computers
> monitoring radio telescopes.
>
> "If you could hear the signal at the frequency it is received,
> it would sound like a faint whistle, a pure tone which could
> only be made by a transmitter. As far as we know, nature can't
> make a pure sound," said Shostak. Each time one of these signals
> is detected by a radio telescope, an alarm alerts SETI
> astronomers, who work around the clock. None has yet been
> pinpointed or recorded a second time, so that scientists have
> been denied the chance of making a study of their source or
> composition.
>
> SETI is stepping up efforts to increase its chances of
> relocating one of these signals and has secured agreement to use
> the world's largest radio telescope - which was featured in the
> James Bond film GoldenEye - at Arecibo in Puerto Rico.
>
> The Americans are also negotiating with British astronomers to
> launch a five-year project to allow speedy verification and
> tracking of these elusive noises.
>
> Whenever SETI identifies a suspect signal, radio telescopes at
> Jodrell Bank will scan the same section of the sky to locate it.
> In this way the scientists can rule out possible terrestrial
> interference from radar, traffic and even electric fences as a
> cause.
>
> "I'm sure there are signals that have come and gone that we
> couldn't get to the bottom of. That's not to say it's little
> green men trying to communicate with us, but we just don't
> know," said Dr Tom Muxlow, an astronomer at the British radio
> astronomy observatory. He disclosed that Jodrell Bank had picked
> up about six rogue signals.
>
> The possibility that the signals have extra-terrestrial origins
> cannot be ignored, according to Nobel laureate Tony Hewish,
> emeritus professor of radio astronomy at Cambridge University.
> In 1967 Hewish and Jocelyn Bell, a student, believed they had
> found evidence of an alien first contact when they detected a
> regular pulse of radio signals coming from a distant star.
>
> "It all had an air of unreality about it, but for a month we
> thought it was possible that the signals were coming from
> intelligent life on another planet. When radio astronomers pick
> up signals that are very peculiar they take it with a big pinch
> of salt, but you cannot remove the possibility," said Hewish.
> Instead, they had found a pulsar, a rapidly spinning neutron
> star, a discovery for which Hewish won a Nobel prize in 1974.
>
> Shostak is not put off by the prospect that any signal from an
> alien world would probably be indecipherable. "If we heard from
> an ET, it would be from a civilisation that is a long way ahead
> of us, maybe even a million years more advanced than we are," he
> said.
>