says, as it is detectable and recognizable.
A few searches have, in fact, looked at
existing data for waste heat radiated by
such spheres, but have found nothing.
In the meantime, Drake proposes that
scientists look for another type of satellite —similar in that it captures energy
from the sun. Space-based solar power
stations may someday soon become a
reality around Earth. Drake speculates
that an Earth-orbiting station radiating a
gigawatt of power back to Earth would
leak about 1 percent— 10 million
watts— into space, a powerful narrowband signal.
“We don’t have to do anything special
to look for these,” Drake says.
He and most others agree that SETI’s
approach should be multidirectional — let
a thousand alien hunters bloom. The only
ideas that don’t do anybody any good,
Horowitz says, are the ones for which
there is no conceivable way to look. “I’d
like to keep an open mind,” he says, “but
not so much that my brain falls out.”
Physicist Paul Davies of Arizona State
University in Tempe, however, suggests
that researchers don’t need to know what
to look for. Find the fishy thing first, and
then argue about its origin, he says.
Out of the box
Davies hosted a conference at Arizona
State in 2008 to get scientists thinking
about possible signatures of alien technology. He contends that SETI programs
shouldn’t just look for what’s fashionable
( because it won’t be fashionable for long).
Instead, look for any strange signature.
“What has happened, in a way, with
SETI is that it has become almost respectable,” Davies says. “It started as a daring
Davies doesn’t think the idea that
extraterrestrial intelligence would contact Earthlings directly via a narrowband
radio beam is credible. Extraterrestrials
wouldn’t know about Earth intelligence
unless they lived within a few dozen light-years, the distance Earth broadcasts have
traveled. And he doesn’t think eavesdropping on extraterrestrial-extraterrestrial
communication is realistic, either. Long-distance conversations would probably
If ET built a space-based power station (artist’s conception) to capture energy from
a star, the power leaked into space could be detected by radio telescopes on Earth.
be spread across many channels and difficult to separate from background noise.
Instead, Davies argues that SETI programs need to look for “footprints” in
the cosmos or here on Earth, and he calls
on all scientists to get involved by simply being aware (see Page 30). Geologists
might take note of any odd formations
or signatures— similar to the natural
nuclear fission reactor that went critical
1. 5 billion years ago in Gabon. When cosmic anomalies emerge — like the absence
of expected planets, lighter-than-pre-dicted comets or odd spectra from
stars — astronomers could consider ET
interference. And biologists could look
for encoded messages through repeated
patterns in viral RNA.
Perhaps aliens are millions of years
ahead of humans: The Earth is relatively
young. If ET passed through Earth’s
neighborhood before humans evolved,
maybe the travelers left a yet-to-be-detected monument or yet-to-be awakened machine on the moon or at the
Lagrange points —the five orbital positions where objects can be stationary
relative to the Earth and the sun.
“SETI requires a little bit of suspen-
sion of disbelief,” Davies said in a talk in
January at the Royal Society in London.
“If we are going to make progress, we
need to think a little bit outside the box.”
Like Davies, many at the SETI Institute
advocate recruiting the help of people
outside the community. A program called
setiQuest was launched in 2010 after Jill
Tarter, director of the institute’s Center
for SETI Research, received a prize from
the nonprofit group TED for her wish
to “empower Earthlings everywhere to
become active participants in the ulti-
mate search for cosmic company.” The
program encourages the public to develop
new ways to analyze radio signals.
s SETI Institute: www.seti.org
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