This does, of course, assume that all alien civilisations are familiar with the ASCII character set.

While browsing the internet today at lunchtime (yes, it was at work, but if they're going to give me an hour to eat lunch and also give me an unrestricted internet connection, the two are going to intersect sometimes), I came across Hello From Earth. This is a project that aims to send a whole lot of messages out to the nearest Earth-like planet we've yet found in the Galaxy, Gliese 581d. (Shame they couldn't come up with a snappier name.)

It's referred to as "Earth-like" because it's in the so-called "Goldilocks zone" of its parent star, Gliese 581. That means that it's neither too hot nor too cold, but the right temperature for liquid water to exist. Perhaps, then, we might find the much-vaunted "life as we know it" there. That is quite a large assumption — after all, we probably wouldn't notice if someone speculatively sent a burst of radio waves at our planet from squillions of miles away. Assuming, therefore, that it'll work at Gliese 581d, if there is indeed water there, and if there is indeed life, and if that life is advanced enough to detect radio, and if it happens to be listening at the time, and if it can decode our messages in any meaningful way, seems to be a bit of a tall order.

Not that it matters, really. Obviously it would be cool if someone did turn out to be listening, but the real value here is in seeing the kinds of things that people want to send out to the cosmos. Some of them go with general friendly greetings; Katrina from California, for example, will send the following:

Hello from Earth ! We come in peace. I look up at the universe every night wondering what magnificent things are out there, this could be one of those things.

Very nice, but perhaps not very informative. Other people have gone down the "dire warnings to the aliens" route, like CruelAngel from Budapest:

For your own safety... You should NOT land on our planet. It stinks.

A little pessimistic, perhaps.

There's plenty of vague platitudes, messages directed more at the people reading the site than at any hypothetical aliens, and (this being the internet) attempts to slag off everyone else using the site, although the fact that all messages must be verified and approved has kept the spam to a minimum. There are some funnier ones that I do like, though:

If you plan to study our species, please don't start with our television broadcasts. They require a lot of explanation.
Eric Zak
Phoenix, United States

To the owner of a red Porsche 944, your lights are on.
H C
Wichita Falls, United States

Hello from Earth, please visit. We have cookies.
Chris Hully
Ottawa, Canada

Xenu, save us!
Tom Cruise
LA, United States

And lastly we have the people who are determined to demonstrate that the Earth holds advanced civilisations, and that we know stuff. I particularly liked this one from Luiz in São Paulo:

3,14159265358979323846 ***, * **** * ***** ********* ** ****** ***** *** ***** ******** ********* ******* ********* *** ** *** ******** **** ******

Simple and elegant.

So what, I hear you ask, did I decide to send? Well, I managed to up my geek points considerably by transmitting the following out into the Galaxy.

. . .. ... ..... ........ ............. ..................... .................................. .......................................................

Yes, with all the vistas of human knowledge open before me, I opted to send them the Fibonacci sequence expressed in full stops. I hope they're grateful for it when it turns up in December 2029.