Fwd: Mysterious signals from 1000 light years away | New Scientist
- Mysterious signals from 1000 light years away
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
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
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
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.”
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
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.
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.
- 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
>it's a zero on the rio scale.are all
>none of our candidates are very interesting - they
consisitent with noise. we will continue to observe
of the candidates over the next few years, but there's
nothing on the candidate lists we are particularly
>a reporter from new scientist read the seti@home webpages:
in particular there's a section on "candidate signals"
we discuss how we score signals and we show the data
the 220 candidates we re-observed at arecibo 1.5 years
these web pages are old, but the reporter made an
story about them, by exagerating their content and
us and quoting us out of context, and making a press
about one of the candidates that has a bit higher
>i talked to a couple of reporters today, explainingwe've seen
stuff like this for the last 30 years, and it's always
out to be rfi or noise, and that there's nothing to
about, and that when you look at 50 trillion bytes of
occasionally you'll find patterns that look unusual
>i wish we had something in our data to get excitedabout.
>tomorrow we'll start using the multibeam receiveryou 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,The Rio Scale to which Dan refers is a one-to-ten tool
use for quantifying the importance of a candidate
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!
Dave Ocame, N1YVV
East Shore Park Observatory