Just read an interesting article on the possibility of "intraterrestrial" silicon-based life on Earth:
SETI spends enormous amounts of money and resources looking for life outside of Earth's realm, but life forms so alien that scientists may simply not have recognized evidence of their existence could inhabit the Earth, according to a leading scientist.
Dr Tom Gold, emeritus professor of astronomy at Cornell University in America, believes that organisms based on silicon - completely unrelated to all the carbon-based life man has encountered so far - may live at great depths.
In a forthcoming book he will suggest that scientists should take the possibility more seriously. Gold, who is a member of the Royal Society, previously predicted that vast amounts of more conventional bacteria live miles down within the Earth's crust. Scientists initially dismissed the idea, but many now agree with him.
"So long as nobody suspects there could be silicon-based life, we may just not be clever enough to identify it," he said last week.
Rocks bearing signs of silicon-based organisms may already be sitting in laboratories, he believes, with their significance overlooked.
Every known living organism, from bacteria to mankind, is based on the chemistry of carbon, which forms the complex molecules such as DNA that are central to our existence. Scientists believe that if extraterrestrial life is found, the chances are that it, too, will be carbon-based.
Editor's Note: While the prospect of silicon-based life is an interesting subject for further research, what the above scientists failed to note is that there is already a large population of Silicone-based life, particularly in Hollywood. Of course they probably can't get government funding to research THAT subject!