Why Is SETI Important?
SETI- General Information
SETI Institute Information
SETI Institute Welcome PageWhat 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. It continues on as Project Phoenix, now totally privately funded.
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 supercomputers, on 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 of 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 has happened since the NASA SETI Program was 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 continues to raise private funds to carry on the Targeted Search portion of the HRMS as Project Phoenix. The first observations for Project Phoenix took place at the Australian Parkes Observatory.
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 does the SETI Institute's 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:
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 BETA 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.
What will happen if a signal is received? Will information be withheld?
In order to confirm that a signal is from another civilization, at least two observatories must be able to receive it. Once an artificial signal is confirmed as being of extraterrestrial intelligent origin, the discovery will be announced as quickly and as widely as possible. A Declaration of Principles Concerning Activities Following the Detection of Extraterrestrial Intelligence, endorsed by six international space organizations, addresses how to make such an announcement. The SETI Institute has a plan for action that resembles the Declaration of Principles. The intent of the plan is to ensure that news is distributed rapidly and widely. In fact, as part of the process of confirming a potential signal, SETI Institute scientists will contact other observatories to investigate candidate signals with their own equipment.
How will we know what the signal means?
If the signal is intentional, it is likely to be easy to decode. In order to send or receive a signal over interstellar distances, a civilization must understand basic science and mathematics. Hence, a message from another civilization would probably use a language based on universal mathematical and physical principles. Signals that a civilization uses for its own purposes may be difficult to decipher. Such emissions may have no detectable message content.
Will the senders have any way of knowing that their signal is received?
Not right away. For the senders to know, we would have to send a message in reply. The SETI Institute has no plan for replying. Under an International SETI Post-detection Protocol now under consideration, the nations of the Earth would decide together whether and how to reply.
If we are looking for a signal, are we also sending any signals?
Project Phoenix is designed only to listen for signals, not to send them. However, since the early part of this century, the cultures of the planet Earth have been unintentionally transmitting signals into space -- radio, television, and other communications transmissions as well as military radar. Our earliest TV transmissions have traveled out into space more than fifty light years.
A few mostly symbolic intentional messages have been sent. One message, broadcast in 1974 from the Arecibo Observatory, was a simple picture describing our Solar System, the elements important for life, the structure of the DNA molecule, and the form of a human being. The message was transmitted in the direction of the globular star cluster, M13, about 25,000 light years away.
What if no signal is detected?
Even if the search does not detect a signal from a distant technology, it is likely to provide many benefits to society. The technology developed to search for faint signals from distant planets can be applied to more down-to-earth problems in medical diagnostic imaging, resource exploration, and materials testing. The SETI Institute, with funding from NSF and NASA, has already developed an important spin-off from the HRMS project, science curriculum enhancement materials for grades three through nine. The subject of extraterrestrial civilizations provides an almost irresistible magnet for attracting young people to the study of science and mathematics. The plan is to keep looking , keep increasing the sensitivity, and keep developing the technological spin-offs that have resulted from the research involved.
What do other scientists think of the search for extraterrestrial civilizations?
From the Report of the Astronomy Survey Committee, the National Academy of Sciences, 1972:
"... More and more scientists feel that contact with other civilizations is no longer something beyond our dreams but a natural event in the history of mankind that will perhaps occur in the lifetime of many of us ...
In the long run, this may be one of science's most important and most profound contributions to mankind and to our civilization."
From the Report of the Astronomy Survey Committee, National Academy of Sciences, 1982:
"... It is hard to imagine a more exciting astronomical discovery or one that would have greater impact on human perceptions than the detection of extraterrestrial intelligence."
From the Report of the Astronomy Survey Committee, National Academy of Sciences, 1991:
"... The discovery in the last decade of planetary disks (around other stars), and the continuing discovery of highly complex organic molecules in the interstellar medium, lend even greater scientific support to this enterprise."
Every ten years, the National Academy of Sciences reviews scientific projects and has recommended SETI three times consecutively.
How much will Project Phoenix cost?
About $4 million/year which could be realized either through commitments for annual contributions or from an endowment of about $100 million. To put it in perspective, this amounts to a little more than a penny per American per year.
Why should we spend millions of dollars on this project when we face a huge budget deficit and homeless people live on our streets?
A society must invest in its future. Over the last few centuries, scientific research has dramatically improved the quality of life and improved our understanding of the universe. The SETI is based on recent discoveries in many fields of science that indicate that other planetary systems and even extraterrestrial life are highly probable. As with many scientific programs, the SETI has potential spin-offs of advanced technology that may benefit the U.S. and its citizens. If successful, the knowledge that we are not alone may have an impact on society as profound and long lasting as when Copernicus removed the Earth from the center of our Universe.
Does Project Phoenix look for UFO's?
No. The search strategy is designed to detect signals from technological civilizations elsewhere in the Galaxy. It has nothing to do with UFO's.
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Why Is SETI Important?
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