What Happens if a Signal is Found
By Seth Shostak
SETI Institute

If you chanced to be among the handful of visitors wandering the
lava-strewn landscape of northeastern California on July 18, 2006, you
might have seen the preamble to what could be a very giant leap for
mankind.  In the dusty pastures edging the town of Hat Creek, in the
northern shadow of moldering Mt. Lassen, ten antennas revved their
motors, and panned the sky.  They were making their debut as the first
working elements of the Allen Telescope Array.
This new instrument which—when completed—will brandish 350 antennas,
can speed up the search for signals from other societies by hundreds of
times and more.  Compared to earlier efforts, it will turn SETI on its
metal ear. We're not talking about the difference between a Lexus and a
Toyota; we're talking about the difference between a Lexus and an
oxcart.

In the next two dozen years, the Allen Telescope Array will parse the
nearest thousand light-years of space.  If there are other occupants
of this galactic neighborhood, we could turn up a signal.
But then what?  Would the discovery be put under wraps, either
voluntarily or by government edict?  If we found a signal, would you
know?

This is among the most commonly asked questions of SETI: what happens in
case of a detection.  Conditioned by television, movies, and a
penchant for expecting conspiracy, a lot of people think that the truth
would not be out there.  They believe it entirely reasonable to expect
that the military, worried that the aliens will threaten the planet,
would surround the telescope with chain link, and redirect the data
stream to the Pentagon.  Another common assumption is that the
government, figuring that the citizenry will lose its cool, stampede the
streets, and provoke a seismic collapse of polite society, will keep the
discovery under wraps.  Some even venture the thought that SETI
scientists, for unspecified (and hard to imagine) reasons, would deprive
themselves of future funding and the Nobel Prize by squirreling away
their find.

Not a chance.  And the reason I say that is, first and foremost,
because the handful of researchers doing SETI experiments are intensely
keen to find treasure, not to bury it.  But even if you don't respect
the integrity of the scientists, even if you think these dedicated folks
have motives that are secret and suspect, then you should at least look
at the process.  Frankly, secrecy is ruled out by how the experiment
is done.

What happens when a signal comes in
Now I've written about this matter on these web pages before, but not in
the last five years.  So allow me to refresh memories (if you have
them) by noting that there's a protocol that outlines the activities to
be followed by any individual or organization that finds an
extraterrestrial signal.  In short, this document, constructed by an
international group of SETI scientists, boils down to the following
action plan in case of a suspected transmission from an alien world:

First, the discoverers should verify that the signal is really
extraterrestrial and artificial, not man-made interference or natural,
cosmic static.  Having done so, those who made the discovery are to
notify all the other signatories to the document so that they can
independently proceed to check it.  They should also inform national
authorities.  Next on the list of those notified are all the world's
astronomers, so that every available telescope can be used to study the
source of the signal.  And then there's this, verbatim from the
protocol; namely that the detection "should be disseminated promptly,
openly, and widely through scientific channels and public media…"
Sounds straightforward, right?  And it is.  However, this protocol
assumes an orderly procession of events, with detection quickly followed
by verification, which is then followed by spreading the news.

Well, real life is messy, as Pigpen knew. The disorder arises from the
fact that the highly sensitive antennas used by SETI, coupled to digital
receivers monitoring a hundred million channels or more, turn up signals
all the time.  When we were using the Arecibo radio telescope in
Puerto Rico, there were detections falling out of the receivers every
few seconds.  This is not like in the movies, when a control-room
oscilloscope suddenly goes from flatline to a profile resembling a
sharpened pencil point, encouraging bored-looking scientists to wake up
and start screaming. In reality, sifting through all those signals to
see if any have the characteristics of an extraterrestrial source takes
a long time.  It's days before you're sure, or at least reasonably
sure.

That's a very important, and currently unavoidable fact.  Another
relevant circumstance is that SETI is done in the open.  For example,
at every radio telescope we've ever used, there are observatory (not
SETI) personnel in the control room 24/7, not to mention local visitors
and a raft of other interested parties (Jimi Hendrix's sister, several
Silicon Valley executives, Isaac Asimov's daughter, and Miss Puerto Rico
are among many who toured the control room at Arecibo during Project
Phoenix observations).  If we're looking at an interesting
signal—one that's passing the tests that can separate the local
interference from an extraterrestrial transmission—then a lot of
people know, even before we call up someone in another state or another
country to verify its reality.  The excitement begins to build long
before the detection is confirmed.

What happens thereafter departs from the protocol, because the media
start calling.  When, in June of 1997, we had a suspicious signal on
our computer screens, a New York Times science reporter was on the phone
with me within hours. At the same time, a TV crew was, by chance, in the
control room of the telescope.  As it turned out, that signal, which
slipped by our usual software filters due to an equipment malfunction,
was from a European research satellite (SOHO) whose telemetry was
bouncing around the steelwork of the radio telescope.

It all means the following: you will be media-blasted about a possible
detection days before the people who find it are certain it's for
real.  (This may pose a dilemma for SETI Institute scientists, who
always keep a bottle of champagne at the observing site. When do we pop
the cork?)  There's also the near-certain consequence that there will
be false alarms for SETI experiments in the future, as reporters
describe interesting signals which, upon closer inspection, turn out to
be telecommunication satellites, airport radar, or just electronic
noise.

Because verifying a signal is slow and the media are fast, there will be
days of uncertainty for any newly detected candidate signal. 
Consequently, some members of the SETI community have devised an index
of a signal's credibility, known as the Rio Scale. This scale evaluates
with a numeric grade any claim of a detection, as judged by SETI
researchers themselves. The researchers award their grade on the basis
of the signal's technical characteristics.  Sure, the Rio Scale is not
a perfect gauge; it's not magic.  But it is expert opinion, and should
help the interested public by making manifest the judgment of an
international group of SETI practitioners. 

In the end, of course, and like all good science, a real detection will
be confirmed by a wide range of observations, involving observers from
many countries during the course of days or weeks.  Facts are, the
first discovery of a signal from an alien world will break into the
world's consciousness in a haphazard, messy fashion. The news won't be
crisp and well-defined.  But it will be very, very exciting.