For many years, the Roman Catholic Church taught that the Earth was the center of everything, and this view was supported by Ptolemy based on the then-known orbits of the planets. It was Copernicus who determined that the planets orbited the sun, and not the other way around. With each discovery we were further displaced down the rungs of a very long ladder. It is now known that even our solar system is in the outskirts of a common galaxy, and our galaxy's place is not unique in a universe of a hundred billion galaxies. Life on this planet is found in just about every nook and cranny, from the deepest ocean trenches to the boiling pools of Yellowstone; it seems that the only requirements for life as we know it are water and a source of energy.
In 1584, a Dominican priest and philosopher named Giordano Bruno wrote, "There are countless suns and countless Earths all rotating around their suns in exactly the same way as the seven planets of our system. We see only the suns because they are the largest bodies and are luminous, but their planets remain invisible to us because they are smaller and non-luminous. The countless worlds in our universe are no worse and no less inhabited than our Earth." In 1600, he was burned at the stake for his words. Although we no longer punish people in such a way for belief in extraterrestrial civilizations, there are still some who would attempt to destroy the reputations of those who are believers, with one popular televangelist actually advocating that they be stoned to death, according to the Old Testament custom for punishing heretics. Fortunately, the majority of our population is enlightened enough not to consider such a barbaric reaction.
The SETI (Search for Extraterrestrial Intelligence) program is seeking an artificial radio signal from afar, but so far no definite signals have been received. There have been false alarms, such as from pulsar stars, satellites, or aircraft, but alas, no genuine signals. There has been one possible signal that cannot be proven to be natural, and it is being studied more closely. The signal is designated SHGb02 + 14a, and has been picked up several times. It is thought to originate several thousand light-years away, and does not appear to be produced by any known natural means. It has a frequency of 1420 MHz, which is the most likely frequency to be selected by an extraterrestrial civilization to broadcast a radio alert, because it is in a relatively quiet zone, and free of natural interference. If it does prove to be artificial, it would have been broadcast several thousand years ago, and there is no telling what the originators of that signal are doing now.
Some years ago, the radio telescope at Arecibo, Puerto Rico, sent out a signal that, if deciphered, would tell a little about us as human beings and where we live in the galaxy. It was sent out to a globular cluster some 80,000 light-years away. In the signal, the first set of symbols (white) represents the numbers 1 to 10, reading from right to left. The cluster in the center (purple) codes the atomic numbers for certain elements. The green-colored patterns represent formulas for sugars and bases in nucleotides of DNA. The white vertical bar specifies the number of nucleotides in DNA. The double helix of DNA is represented by the blue curving lines that go from the sugars/base formulas to the human being. The next symbol to the left of the human figure represents the human population on Earth, and the ones to the right side of the human figure represent the height of a human being. The yellow symbols represent our solar system, with the Earth displaced upward to the human figure. The purple symbols represent the Arecibo Telescope, and the white and blue symbols on the bottom represent its diameter.
Some people are worried about these attempts at contacting an extraterrestrial civilization, because we have no way of knowing how they would perceive and react to knowledge of our existence. In fact, though, it is a bit late to hide our presence: Our radio and television signals have been broadcasting our presence for 80 years. Television signals dating back to the Berlin Olympics in 1936 are now passing stars up to 70 light-years away. (The Carl Sagan book Contact was based on the scenario that these signals were picked up and responded to, but because of the tremendous distance of 26 light-years, we did not receive their response until 52 years later.) Like it or not, we have made our presence known to ETs that may be in star systems up to 80 light-years away.
We can hope that the extraterrestrials visiting us are more like E.T. than the ones depicted in Independence Day. But the truth is, both types are probably out there, and we are lucky that the ones in our skies appear to be more like E.T, the botanist. We know full well what happens when an advanced civilization comes into contact with one that is less advanced; we have plenty of examples here on Earth: What happens first is conflict, then subjugation, and finally assimilation. So far, none of this seems to be happening with our experiences. The more likely scenario is that we are a scientific curiosity to be studied rather than interacted with.
We know that there are spacefaring civilizations out there, and, moreover, that they have shown an interest in us with their investigatory probes. If you believe in the abduction phenomena, then you have to consider that these beings have taken a personal interest in us. Reputable investigators such as Budd Hopkins are conducting strong research that is difficult to refute, although significant effort has been expended by some skeptics to do so. Knowing Budd as I do, and being aware of the methods he uses in his research, I have to believe that, on rare occasions, alien abductions must occur. I think they are studying us just as we would study other life forms here on Earth. I believe that these beings have a keen scientific interest in our physical and scientific development, and that they don't represent a danger to us, and we don't have anything they want-if we did, we would not be here.
A significant number of rather interesting discoveries in places all over the world suggest that Earth has been of interest to extraterrestrial visitors for thousands of years. There are ancient cave paintings of humanoid creatures clad in what appear to be protective suits such as space suits, complete with helmets. Primitive drawings have been discovered of inhuman creatures with round heads and large eyes. In some Egyptian tombs, pictures have been found of what appear to be aircraft. In the Nasca Plains south of Lima, Peru, alongside line drawings of animals are seeming depictions of airfields and runways. These drawings are imperceptible from the ground, and so were not discovered until the 20th century, when people began flying over the area. England boasts similar ancient drawings that can only be seen in complete context from the air. The existence of such artifacts raises the question: Why would the ancients spend the time and effort to make line drawings that can only be appreciated from a vantage point that they are unable to reach?