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Subject: SETI FAQ:  Part 1
Date: 25 Jan 1995 16:43:41 GMT
Organization: Duke University
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This is the SETI FAQ from their Web page.  I removed the HTML code and
did a little straightening.  Begin Part 1...

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SETI - Frequently Asked Questions

What is SETI?

SETI stands for Search for ExtraTerrestrial Intelligence.  It is an effort to
detect evidence of technological civilizations that may exist on planets
orbiting other stars.  Potentially, there are billions of locations outside
our solar system that may contain life.  With our current technology, we have
the ability to discover evidence of life in those planetary systems where
life has developed a technology that modifies its environment in such a way
as to be detectable across interstellar distances.

Didn't NASA conduct a SETI program?  Why were they interested?

NASA's interest in SETI stems from two reasons:

1.) NASA's charter for research includes the study of the origin and
distribution of life in the universe, and

2.) intelligent, technological life provides a means of detecting planets
orbiting other stars, a goal of NASA's Toward Other Planetary Systems
program.

NASA conducted fifteen years of research and technology development and
invested $58 million of the taxpayers' money culminating with the start of a
planned ten year observing program in October, 1992.  The project was called
the High Resolution Microwave Survey (HRMS).  After only one year of
observing with prototype systems, the project was canceled by Congress due to
budget pressures.  It was by far the most comprehensive search ever planned.

What made the NASA HRMS special?

Although many searches have been conducted during the past three decades,
the NASA HRMS was far more capable and comprehensive.  The HRMS planned
to systematically search for a variety of signals, over the entire range of
the most promising microwave frequencies, using special-purpose super
computers, in the largest available radio telescopes, with real-time signal
detection and verification.  The NASA search was also composed of two
complementary strategies: a Targeted Search of selected solar-type stars and
a rapid Sky Survey of all directions on the sky.  Other searches typically
were sensitive to only one type of signal, covered only a narrow range of
frequencies, used less capable equipment on smaller antennas, and could not
immediately check candidate signals.  In the first minutes of operation, the
HRMS accomplished more searching than all previous programs combined.

What will happen now that the NASA SETI Program has been canceled?

Signal processing systems developed for the Sky Survey portion of the search
will be incorporated into NASA's Deep Space Network.  NASA has agreed to loan
the systems developed for the Targeted Search to the SETI Institute.  The
Institute is now raising private funds to carry on the Targeted Search
portion of the HRMS as Project Phoenix.

What is the SETI Institute?

The SETI Institute is a non-profit corporation that serves as an
institutional home for research and educational projects relating to the
search for extraterrestrial life.  The Institute conducts research in a
number of fields including all science and technology aspects of astronomy
and planetary sciences, chemical evolution, the origin of life, biological
evolution, and cultural evolution.  Institute projects have been sponsored by
NASA, NSF, JPL, DOE, the USGS, the IAU, Argonne National Lab, the Alfred P.
Sloan Foundation, private industry, and private donations.  There are
currently about twenty active projects at the Institute.

How will the SETI Institute Project Phoenix operate?

The SETI Institute was the major developer of the instruments for the HRMS
Targeted Search.  NASA will allow the Institute to use the instruments for
continuing research now that the HRMS has completed its termination phase.
The Institute has retained the core science and engineering team from the
HRMS Project and along with its subcontractors is now completing a planned
upgrade and expansion of the Targeted Search electronics and software.  Since
February, 1994, all work has been supported by private donations.

If annual funding of approximately $3 million can be secured, the SETI
Institute will become the focus of SETI efforts world wide.  It will
accomplish the planned Project Phoenix observing program while conducting a
parallel effort to design and develop systems of much greater capability.

How long will Project Phoenix last?

The time to complete the observational phase as originally planned by NASA is
expected to last until 2001.  The actual time needed will depend on the
availability of observatory facilities and the level of terrestrial radio
frequency interference, the rate at which improvements can be made in
receiving systems, and whether or not a valid signal is detected.

How is Project Phoenix different from previous searches?

The SETI Institute Targeted Search has a number of features that distinguish
it from previous and current searches:

-continuous spectrum coverage with narrow frequency channels over a wide
-range of frequencies, from 1,000 MHz through 3,000 MHz;

-real-time data processing; i.e., immediately attempting to verify
-candidate signals

-search for both continuous and pulsed signals

-search for signals that may drift in frequency

-use of the largest available radio telescopes (45 to 300 meters) for high
sensitivity.

Haven't astronomers been searching for radio signals for decades?

Physicists Philip Morrison and Giuseppe Cocconi authored the first scientific
proposal for using radio waves to transmit information over interstellar
distances. This proposal appeared in the journal Nature in 1959.  In the
following year, Dr. Frank Drake conducted the first radio search for evidence
of technology in other solar systems using an 85-foot antenna of the National
Radio Astronomy Observatory in West Virginia.  This search, called Project
Ozma, observed two stars about 12 light years away.  Since that time, more
than 60 searches have been conducted by dozens of astronomers in at least
eight countries.  All but a few of these searches have been limited in
duration, using only a fraction of a percent of available radio telescope
time.

In the first minutes of observations on October 12, 1992, the NASA HRMS
scanned more of the astronomical search space and analyzed more data
than the sum of all previous searches.  Project Phoenix will retain that same
level of search capability.

Have any previous searches found anything?

No.  All searches thus far have been very limited in one respect or another.
They have generally used equipment that was designed for other purposes.
They also faced limitations in sensitivity, frequency coverage, types of
signals they could detect, and the number of stars or the directions on the
sky that were observed.

However, in spite of these limitations, many of the searches have found
unexplained signals.  Because data collected in these searches were often
processed long after the observation, no candidate signals could be
immediately checked to see if they were of extraterrestrial origin.
Subsequent observations conducted days to months after the original
observations have never found any of the candidate signals.  In order to be
sure that a signal is from another civilization, it has to be independently
verified and shown to originate from a point beyond the Solar System.
Project Phoenix will immediately test candidate signals.

Why do we think that there is life "out there"?

Over the last half century, scientists have developed a theory of "cosmic
evolution" which predicts that life is a natural phenomenon likely to develop
on planets with suitable environmental conditions.  Scientific evidence shows
that life arose on the Earth relatively quickly, suggesting that life will
occur on similar planets orbiting Sun-like stars.  With the vast number of
stars in the observable universe (up to 400 billion in our galaxy alone) and
the probable number of Earth-like, habitable planets around other stars, it
is likely that advanced technological civilizations are widely distributed in
space.  SETI tests this hypothesis by searching for specific technological
manifestations of intelligent life.

How could any kind of technology could be detected at such great
distances?

Technology has many uses, among them are communication and active detection
and ranging (radar, lidar, etc.).  To accomplish these activities on Earth,
our technology uses electromagnetic waves such as light, radio, and infrared.
 To be detectable over interstellar distances, such signals must not be
absorbed by interstellar plasma.  Radio waves travel through space with the
least absorption or distortion.  Most SETI searches concentrate on
microwaves, radio waves in the frequency range from 1,000 MHz to 10,000 MHz.
Radio waves emitted by natural astronomical objects are spread over bands of
frequencies wider than a few hundred Hertz, are seldom polarized, and are not
constant in phase.
Artificial signals, produced by a transmitter and antenna, are often confined
to a narrow range of frequencies, are highly polarized, and have the peaks of
the waves in phase.  Artificial signals may contain encoded information,
while natural signals do not.

Why can't we just send a spacecraft out to look for other planets and
life orbiting other stars?

With our best rocket technology a flight to the Sun's nearest neighbor, Alpha
Centauri, only 4 light years away, would take about 40,000 years.  Even a far
more advanced technology cannot avoid either paying a huge energy cost or
going very slow.  Relativity and the limit of the speed of light apply
throughout the universe.  About a thousand stars like the Sun are within 100
light years of us.  To search around all of them with spacecraft would take
more than a million years and vast amounts of money.  Alternatively, we can
search for radio waves now, with state-of-the-art technology, at a modest
cost.  The observational phase of the HRMS would have cost about a nickel per
taxpayer per year.

Who is currently supporting and carrying out searches?

University of California, Berkeley, astronomers are carrying out a search
called SERENDIP III at the Arecibo Observatory in Puerto Rico.   The
Planetary Society, an independent, privately funded organization, operates
Project META at Harvard University and in Argentina.  Ohio State University
conducts an ongoing full-time search with a large volunteer effort.  Besides
the HRMS, NASA has also funded a search at infrared wavelengths at UC
Berkeley, part of the SERENDIP program, upgrades to the META system
at Harvard and the Ohio State system.  Smaller scale, limited searches have
been and continue to be conducted by individual scientists in the United
States and other countries.  The SETI Institute is now raising private funds
to continue the Targeted Search portion of NASA's HRMS as Project Phoenix.

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Continued in next...

dpk