SUBJECT: THE SEARCH FOR EXTRATERRESTRIAL INTELLIGENCE FILE: UFO2804 BY DAVID L. BURKHEAD Are we alone? The question is often asked by those involved in the search for extraterrestrial intelligence (SETI). It has tugged at the mind of humankind since early history, probably since the first time a human looked up at the sky and realized that some of those lights up there were other worlds. The ancient Greeks told stories in which they populated the Moon with people, people who were planning a war with people on the Sun. In the Middle Ages, the Orlando Furioso had Duke Adolpho, one of Charlemagne's paladins, travel to the Moon on the back of a hippogrif to meet some of the folk who resided there. Such ideas seem quaint today, but the idea of life on other worlds is anything but quaint. While none of the other planets in the Solar System are likely homes for intelligent, tool-using life, our galaxy alone contains more than a hundred billion stars, many like our Sun. Current theories postulate that stars like the Sun are also likely to have planets, and if conditions are right on those planets, then life should evolve. The next question is how it might be possible to detect, perhaps even communicate with, such life. For most of history, no means of observing even the worlds around another star existed. However, in 1932 radio experimenter Hiram Percy Maxim suggested that contact with another star might one day be possible by radio. The year before, unknown to Maxim, Karl Jansky of Bell Laboratories, investigating sources of static in radio communications, traced one of these sources to the heavens, specifically to the Milky Way, and thus created the science of radio astronomy. Others expanded on Jansky's work, developing new receivers and large antennas that could examine the sky for radio sources. None of these radio telescopes sought signs of life elsewhere in the universe, but they did develop powerful new tools for the detection and analysis of faint signals coming from deep space. It was these tools that Frank Drake applied to his Project Ozma, the first serious attempt to look for other life in the universe. In 1961 at the radio observatory in Green Bank, West Virginia, Drake observed two nearby sun-like stars considered by many likely to have planets - Tau Ceti and Epsilon Eridani. While Project Ozma did not find any extraterrestrial signals, it did lead to a conference of leading SETI researchers at Grand Bank in 1981. This meeting was organized by the U.S. National Academy of Science and demonstrated that SETI could now be taken seriously in science, even at the highest levels. One result of the conference was the socalled Drake Equation. This equation purports to estimate the number of intelligent, communicating civilizations in the galaxy. Taking such factors as the number of stars in the galaxy, probability of a given star having planets, probability of a given planet developing life, etc., the equation then calculates the number of civilizations expected in the galaxy. Unfortunately, many of the factors are unknown and estimates are little more than wild guesses. Yet estimates are made, and the most common result is about a million communicating civilizations. If scattered evenly about the galaxy, this would put the nearest such civilizations about 700 light years away. This then, is one of the major problems with SETI projects. According to Geoffrey Landis of NASA Lewis Research Center, given our current technology, it would be impossible to detect the Earth from much smaller distances than 700 light years. The only signals that would be detectable even from the nearest stars would be the Ballistic Missile Early Warning System (BMEWS). Yet, because of Earth's rotation, any signal a hypothetical extraterrestrial detected would only appear in short spurts, like many natural sources, unless the exterrestrial's planet were situated along the line of Earth's axis. Since there are no nearby stars along the line of the Earth's axis, the hypothetical alien world could not detect the Earth and realize that they had found signs of intelligence elsewhere. Likewise, it is extremely unlikely that we would detect accidental emissions from other planets. However, there is still the possibility of intentional transmissions. Frank Drake and Carl sagan directed the transmission of the first (and to date only) deliberate message sent into space. Transmitting from the Arecibo Observatory in Puerto Rico, they sent a message consisting of 1,679 pulses that decode into a crude image containing information about our planet, our place in the solar system, and ourselves. This message was aimed at the Great Cluster in the constellation of Hercules. The message will take 24,000 years to reach the distant cluster, so no reply can be expected anytime soon. If we can deliberately send a message into space, perhaps others have done so as well. If any such messages have been sent in our direction, whether or not Earth or the Sun is the intended target, we may be able to detect them. Such messages are what various SETI projects have attempted to detect. The problems faced by SETI researchers are enormous. First is finding the signal. The signal can come from anywhere in the entire sky, and at any frequency. Two approaches are generally used to search for signals. In one, thousands or millions of frequencies are studied in a survey of the entire sky in the hope of finding the needle in the cosmic haystack. In the other approach, and attempt is made to determine what frequencies are likely to be used by extraterrestrials wishing to broadcast to other beings and what stars are likely to have such extraterrestrials, and then to concentrate the search there. This is what Drake did for Project Ozma. The next problem is that even if the signal can be found, it may not be recognized. Nature has a way of conspiring to deceive astronomers about eh nature of signals. In 1967, a source of extremely regular, steady pulses was detected in deep space. Excitement rose, for no known natural source could explain such regular pulses. The idea that they were from a beacon established by extraterrestrials was put forward, but SETI advocates were doomed to disappointment. The pulsating radio sources, known as pulsars, proved to be rapidly spinning neutron stars. While they were exciting discoveries in their own right, they had nothing to do with extraterrestrial intelligence. SETI has largely remained a small sidelight of radio astronomy. Occasionally, projects were funded, but they had to compete with other, more pressing and popular projects. However, that seemed likely to change in 1992 when Congress approved a new, extensive 10-year Search for Extraterrestrial Intelligence to be conducted by NASA. The project would combine both an all-sky survey and a concentrated examination of nearby stars. Ten years proved optimistic. In October of 1993, merely one year after the initiation of the project, Congress cancelled it. That brought direct government involvement in SETI to an end. The SETI Institute of California, a private group, took over the project and renamed it Project Phoenix. So far the group has raised $4.4 million, more than half the $7.4 million required to keep the project functioning. The search for extraterrestrial intelligence is a long, difficult one that will probably not reach its goal for decades, if ever. Yet, many consider the search important. We may be alone in the universe or we may share the universe with possibly hundreds, thousand, or millions of civilizations. Either way, the thought is staggering. ********************************************** * THE U.F.O. BBS - http://www.ufobbs.com/ufo * **********************************************