I read about this a few weeks back on the suns website. I also seem to remember a few years back we had a topic on this forum about ancient civilisations and the signs they could leave behind for the future civilisations to discover them by. If you wanted to leave a symbol to show your existence in several thousand years how would you do it? - China cracks, plastic will eventually erode, metal breaks down.. that leaves rock and stone really doesn't it. We've got pyramids, stone henge.. and somewhere in the middle east a few years back there was a theory of a pyramid that was buried underground. It seems to me that for whatever reason, previous civilsations on this planet have wanted to leave us some sort of sign of their existence. Why? I have no idea. Perhaps there is super cool technology buried under them or something.. no idea but I'm pretty sure they've left their mark intentionally because it's always rock or stone that is used - the longest lasting materials we have.
I need a new signature... i'm bored of the old one!