Worlds of David Darling > Children's
Encyclopedia of Science > Could You Ever Meet an Alien? > 4. Thoughts
COULD YOU EVER MEET AN ALIEN?
a book in the Could You Ever? series by David Darling
4. Thoughts about Aliens
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.
| Using the Arecibo Telescope, scientists
sent this coded message toward a giant cluster of stars – the
globular cluster M13 shown in this photograph
Issues such as these were raised after the Arecibo Message was beamed toward
the distant star cluster M13 in 1974. 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.
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 '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
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
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.
|This photograph of an unidentified flying
object was examined as part of a U.S. Air Force UFO project
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.
|A silicon chip used in high-speed computers.
If advanced alien intelligence does exist, it may take an artificial,
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.
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.
|An artist's idea of alien
life on another world
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.