Science News - April 24, 2010

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 fringe activity.”

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.