Worlds of David Darling > Children's
Encyclopedia of Science > Could You Ever Meet an Alien? > Introduction
COULD YOU EVER MEET AN ALIEN?
a book in the Could You Ever? series by David Darling
Creatures from other worlds – aliens – have us surrounded. In
the movie theatre, on the television set, and from the shelves of every
toy store, they grin and grimace and glower at us. Ugly, comical, fierce,
and friendly – they come in every variety imaginable. All of them,
though, have one important thing in common: they are totally make-believe.
|Around many of the newborn stars in this
photograph of the Trifid Nebula, there may be young planets. On some
of those planets, life may exist now or in the future.
No one has ever seen a real alien. Or, at least, if they have, no one has
yet provided any firm proof that they have seen one. Despite many reports
of unidentified flying objects – UFOs – and even of close encounters with
space creatures, there is not one bit of evidence that aliens have ever
visited us. The only living things we know about for sure are those that
inhabit the Earth.
But look up at the sky on a clear, dark night. Each of the stars you can
see is really a sun. Some of the stars are much bigger and brighter than
our own Sun. Others are smaller and dimmer. With binoculars or a small telescope,
you can locate about 50,000 stars, or 25 times more than with your eyes
alone. A very large telescope shows millions upon millions.
Astronomers have already discovered several hundred planets circling around
other stars. They expect to find thousands more in the years to come. On
some of these faraway worlds, there may be life – perhaps life that
is very different from that which exists on Earth. Even among the living
things we do know about, there is a fantastic variety. It would be hard
to imagine, for instance, anything more unlike than an ant and an oak tree,
or a butterfly and a killer whale. It would be hard to imagine any creature
stranger than the bug-eyed monsters of Hollywood movies. On planets of other
stars, there may even be alien life forms that are much more advanced than
So, could you ever meet an alien? Scientists differ in their answer to this
question. Some argue that there may be no intelligent creatures elsewhere
in space. If such creatures exist, they say, then we should have found signs
of them by now. Others point out that there are so may stars and probable
planets that life, including intelligent life, almost certainly exists somewhere
out there. According to this view, if we keep searching long enough, we
will eventually find alien life forms.
Indeed, the search for life beyond Earth has already begun. With giant instruments,
several groups of astronomers around the world are listening for radio signals
that may be coming from intelligent races among the stars. Several probes
have been launched carrying special plaques and even phonograph records
describing life on Earth. These could provide information about our own
planet to any aliens that ever came across them. Finally, two robot spacecraft
have landed on the surface of our neighboring planet, Mars, and tested for
simple life forms in the soil.
Today, scientists are striving to answer the question: Could you ever meet
an alien? In what follows, we will consider the fascinating progress and
the results they have achieved so far.