SETI and the Aliens

Most people have heard of SETI; the Search for Extraterrestrial Intelligence. It's an easy name to remember and it deals with, as the Institute itself puts it, "the most profound search in human history - to know our beginnings and our place among the stars."

One of its key scientists is Frank Drake who, back in the 1960's, developed a formula for estimating the number of civilizations in the Milky Way which might be intelligent and able to communicate. The result of this Drake Equation, as it has become known, indicates that there is a high chance of alien life existing in the Milky Way.

It does not say anything about rest of the universe!

What does SETI do?

The Institute is scanning the skies looking for aliens, to bring us proof.

Basically, SETI is looking for radio signals. It is looking for them in a narrow band which is near to a well-known 'broadcast', that of hydrogen in the universe. This 'broadcast' is presumed to act as a sort of universal marker so that, if an alien civilization was wanting to be found, it would place its signal near this band so that it could be more easily found.

Of course, there have been no aliens found yet. And that is the most usual dismissal of the Institute. 'After all, it's been looking for over 20 years now and...nothing!'

But those who say that are not really aware of the scale of the problem.

Let's say that an alien is broadcasting from a planet somewhere in the Milky Way. In order to find its signal you first have to exclude all the other interference in our own atmosphere.

Then you have to be able to isolate that signal from all the others and not lose it. (And remember, it's a weak signal in a lot of background noise.) And you have to make sure it really is real. By that I mean you have to make sure that it contains something; a code, a message, a pattern of some kind.

Now let's suppose I give you a small laser beam you can move around, in a room full of slowly moving mirrors, with other lights of all colors flashing on and off irregularly. I then ask you, without moving from where you are, to locate and check the one tiny mirror which is flashing a signal, and it's not necessarily aiming at you.

That's the sort of problem which SETI is dealing with.

Should you hold your breath?

Short answer...No.

It could be tomorrow, it could be years and years down the line. It could be never.

Even if it does find something tomorrow all it really means is that it will be the start of a very long process. It's not like the aliens are going to arrive as soon as we find the signal.

All it will tell us is that we're not alone. And it will tell us via a fuzzy sounding radio signal which won't mean a great deal to most of us.

But whether or not SETI finds anything, it keeps the idea of searching for aliens in the public mind.

And you can also join in with the search! SETI@home is the place to go. Your computer can search for signals while it is idling. You might be the one to find proof of alien life!

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