SETI scientists have been searching for radio signals transmitted from outside the Earth for 38 years. Although so far they have only picked up one unproven transmitter and the US Congress stopped funding their project, they are not giving up
By: Avi Blizovsky
Published as part of the "Third Thousand" section in "Haaretz"
The American SETI Institute (Search for Extraterrestrial Intelligence), which deals with the search for extraterrestrial intelligence, benefited from the free advertisement given to their enterprise in the films "The Third Day" and "Contact". And yet, the people of the institute disapprove somewhat of the way they were presented in the two blockbusters. Thus, for example in "Contact", scientists are the ones who detect radio signals of an approaching spaceship. In reality, on the institute's website, the scientists emphasize that according to the way the institute's computers are designed, this is not possible because the software actually ignores any signal that comes from a distance of less than 400 km (roughly in the orbit of the moon).
SETI is built to listen for signals from distant stars only. Listening to radio frequencies from the stars has existed since 1960, when Frank Drake, an astronomer at the National Radio Telescope Observatory in Greenbank, West Virginia, promised that with the help of equipment he had installed, worth only $2,000, he could detect signals that may originate from living creatures that have developed high technology. In 77, as the weekly Time reports in an article about SETI as part of a special supplement on the discoveries of the century, published a few weeks ago, the most dramatic moment in the institute's history occurred. Prof. Jerry Ekman, who was then the director of the "Big Ear", the radio telescope of Ohio University, came across a paper that was suddenly thrown out by the observation computer. A letter appeared on the output, and the amazed professor added the word "wow" in his handwriting in the margins of the output. "The signal was in the form of a very narrow band, one that an intelligent society could create," recalls radio astronomer Rob Dixon, head of the "Big Ear" today. "It came from a very long way, and lasted 37 seconds." But all the observations directed since then towards the same point from which the signal came, failed to locate it once more.
Not long ago, the "big ear" was in danger. The plate, which covers an area three times larger than a football field, will probably be forced to vacate by the end of the year, as the private owners of the area have other plans. Apart from that, in '93 it became clear that the American Congress believes that the money allocated to NASA for the purposes of listening to the stars, is needed more by the poor on earth. A law passed at the initiative of several senators ordered NASA to stop supporting the project. However, there are enough private donors who are willing to do anything to keep the project alive. "Phoenix" is the name of the new listening project, established on the private initiative of Frank Drake - an astronomer who also signed the equation that tries to locate the number of intelligent civilizations in the universe. Drake, who heads the institute today, raised several million dollars from private sources. The Phoenix group has already sent its search teams to Australia, equipped with a receiver that listens to 56 million channels and a formidable telescope that is 64 meters long. For five months, the team listened through the computer to 200 sun-like stars that are only visible from the southern hemisphere, so the destination chosen for the observation was also Australia. The SETI Institute is also helping another project, which is being carried out at the University of California at Berkeley, called Serendip, where in the next five years they intend to listen to 168 million radio channels. "We have a strong back that allows us to work around the clock," says Stuart Boyer, project manager.
"They," Boyer says, referring to extraterrestrial beings, "do not need much if they have a telescope aimed directly at us. It's not a question of strength. The problem is that they have 200 billion stars to point their telescope at. Therefore, they will be forced to transmit a transmitter that will cover a large sector of the sky, and this requires a lot of power." Boyer is looking forward to the day when he will also start broadcasting, and not just listening. "We can install a radio telescope in some valley at the back of the moon, next to a nuclear plant that will provide it with megawatts of power," he predicts. "Then, when the moon moves around the earth, the other part of it will pass through the sky and the transmitter will be easily detected by a distant company." Today, despite the paucity of findings and negative results, the search for intelligent life continues and even expands to a number of new studies, which are periodically stimulated by small groups of passionate and endlessly patient scientists. Frank Drake also doubts whether, when the signal does arrive, we will be able to decode it, just as it is not certain that an outside civilization will be able to decode our own signals. Drake can only hope that "the transmitter will be in an interstellar language that will allow good communication".
In 74, when he ran the observatory in Arecibo, Puerto Rico, he transmitted a digital message to the stars, containing 1,679 bits. A technological company, he assumes, will recognize that 1,679 bits is the product of the product of 2 prime numbers 73 and 23 (the assumption is that prime numbers are mathematical axioms that do not depend on the computer brain) and will be convinced to translate the transmitter into a graphic array of points. Reading the data in an array of 73 by 23 squares in black and white, they will see a crude counter showing, among other things, a human figure communicating, a third planet in the solar system, a radio telescope, other information about the senders and a simple explanation of the radio code. Of course, so far no response has been received from outside the Earth. But most scientists agree that not only is there a possibility of life in outer space, but also that it is increasing in light of recent discoveries: the presence of planets around nearby stars, and little evidence of ancient life forms in the rocks of Mars. Thus, for example, two additional detection systems are being planned at Serendip, which will be placed in Australia and Italy, and the SETI Institute is also participating in an international program to build a radio telescope, which, according to Drake, will be 30 to 100 times more sensitive than Arecibo. Drake is impressed by what he calls growing evidence that life on Earth originated in the depths of the sea, and that a similar phenomenon could possibly occur on any planet whose surface contains a lot of water.
(c) Appeared in "Haaretz", 29/12/1997
* The editor of the Hidan website was a member of the Ha'aretz editorial board in 1994-2000
