COULD YOU EVER MEET AN ALIEN? 4. Thoughts about Aliens
Figure 1. Using the Arecibo Telescope, scientists sent this coded message toward a giant cluster of stars – the globular cluster M13 shown in this photograph.
Figure 2. The 'Sounds of Earth' record and an American flag are prepared for storage aboard Voyager 2 at Kennedy Space Center in Florida. The record (left) is made of copper and is gold-plated.
Figure 3. This photograph of an unidentified flying object was examined as part of a U.S. Air Force UFO project.
Figure 4. An artist's idea of alien life on another world.
Humans are often violent, both to other people and to other living things on Earth. Because of this, some scientists say, it may not be a good idea to make contact with intelligent aliens. What if they are violent, too? Perhaps by letting them know we are here, we will be inviting trouble.
Issues such as these were raised after the Arecibo Message was beamed toward the distant star cluster M13 in 1974 (see Figure 1). But, in fact, humans had already announced their presence on Earth long before that message was sent. For more than 50 years, our radio and television broadcasts have been leaking out into space. Signals from the earliest programs have now traveled more than 300 trillion miles, past dozens of nearby stars. With the proper equipment, any beings living around those stars could have picked up our programs.
Imagine an alien race listening for intelligent messages from the Sun, just as we are now tuning in to other stars. The first signals they pick up might be a "bill Cosby Show" or an episode from "Dallas." Would aliens understand that these shows are meant to entertain viewers? Or would they perhaps mistake them for news programs?
Greeting Cards from Earth
There are other ways, too, in which we are telling the rest of the Universe we exist. In the 1970s, four spacecraft were launched that are now moving away from the Solar System. They are carrying various messages for anyone who may find them in the future.
Two of these spacecraft are Pioneer 10 and 11. Both have a circular plaque attached to their side on which information is etched about the Earth's position in space. They also show a man and a woman standing in front of an outline of the Pioneer probe.
A great deal more is revealed about our planet and its life forms on a phonograph record carried by two larger spacecraft, Voyager 1 and 2 (see Figure 2). Thoughtfully, each Voyager also carries a needle with which the record can be played. If any intelligent creatures find this message, tens of thousands of years from now, they may be amazed at what they see and hear. Stored in coded form on the gold-plated disks are 117 pictures of the Earth and its inhabitants. These include photographs of a sunset, a group of schoolchildren, and an astronaut. Also on the record are greetings in 54 different human languages, along with the sounds made by a humpback whale. This message would certainly give extraterrestrial scientists plenty to think about!
The chances that any of the Pioneer or Voyager spacecraft will ever be found are incredibly small. As far as mission specialists can predict, none of these probes will go anywhere near another star for hundreds of thousands of years. Even so, these spacecraft, carrying news about the creatures of Earth, are already heading toward the stars.
Are We Alone?
If intelligent aliens did exist, the chances would be high that they are more advanced than us. It is only within the last century or so, for instance, that we have had telephones, radio, and television. In recent times, astronauts have landed on the Moon. But the Wright Brothers made the first mechanically powered flight in 1903, just over a century ago. What would an alien civilization be capable of that had existed for tends of thousands, or even millions of years? Their inventions would probably seem like magic to us. We would certainly expect that they could fly from one star to another in superfast spaceships.
But that idea raises an interesting question. If there are very advanced extraterrestrials, then why have they not visited us yet? You might imagine that a planet as fascinating as the Earth would attract the attention of other spacefaring races. In fact, the absence of any alien starships is taken by some scientists to mean that there are no other intelligent life forms in the Galaxy. According to this view, SETI projects are a waste of time because human beings are the only intelligent life that exists.
On the other hand, some people believe that aliens may already be here. Countless reported sightings of UFOs have encouraged a widespread feeling that perhaps we are being visited by so-called flying saucers (see Figure 3).
In almost every case where a UFO sighting has been fully investigated, there has been a reasonable way to identify it as something else. Unusual clouds, aircraft, or weather balloons catching rays from the setting Sun have all been mistaken for alien spacecraft. One of the most widely reported UFOs, which was seen by President Jimmy Carter, turned out to be Jupiter. It would be exciting, and perhaps a little frightening, to think that we were being watched by beings from another world. And yet, there is no solid evidence to support this idea.
That does not mean that alien spacecraft have never visited the Solar System, or that they will never do so in the future. In the film 2001: A Space Odyssey, science fiction writer Arthur C. Clarke told a story in which intelligent beings from another world have planted devices on the Earth and in space to watch over our race as it develops. Anything is possible when we are dealing with a subject about which we know so little. But it is important to separate fact from fiction.
|Strange Forms of Life
It is difficult to imagine what human civilization will be like 1,000 years from now, much less 10,000 or 1 million years in the future. On thing, though, does seem likely. As time goes on, every means possible will be used to boost the power of our brains and senses.
Today, for example, we use microscopes and telescopes to extend our sight and computers to handle information more quickly. These trends are likely to continue until, over time, artificial beings are created. These new creatures might live with or even replace the human race. On other worlds in the Galaxy, this may already have happened. If so, the first advanced life forms we make contact with may not be made of flesh and blood, but of complex machinery and electronics.
Into the Unknown
Today, we do not know if there is any life beyond the Earth. Scientists' opinions range all the way from near-certainty that there is to near-certainty that there is not. In addition, we do not know what forms alien life might take. If extraterrestrials exist, they may look quite different from us (see Figure 4). Still, they could be based on the same kind of chemicals as life on Earth. On the other hand, there could be life forms in space that we might not recognize as being alive. Just as we study germs under a microscope, so an intelligence far greater than ours may be keeping an eye on us.
Scientists have only just begun the search for other life in the Universe. Could you ever meet an alien? Perhaps one will land in your yard tonight, though the chances of that happening are fairly slim. Or, much more likely, a message will be picked up sometime in the future by a giant radio telescope scanning for radio messages among the stars. If alien life ever is discovered, it will change us in ways that we can barely begin to imagine.
And what if we find nothing out there? That, too, will be remarkable. It will then be up to us alone to explore the Galaxy and look with intelligent eyes for the first time on endless new worlds.