It's life, Jim. But not as we know it.
It is one of the all time classic Star Trek episodes, where the intrepid crew (why is it that all the senior officers were always on the planet at the same time?) were investigating the deaths of miners in the tunnels below a remote colony. They discover a life form based on Silicon, instead of Carbon.
I just loved that concept. Along with the first SF short I read where the aliens breathed Chlorine gas instead of Oxygen, it really stimulated my imagination.
Old Spock ended up doing a mind-meld with the strange rock-creature ("Pain! Pain! They are destroying my children!), and they end up making friends and fixing up the creature with cement mix, then the little rock-creature's children were free to secrete their acid in peace.
The background theory for the Star Trek episode was that as Carbon and Silicon are right above/below each other on the periodic table, and have a similar versatility in terms of available bonding sites (i.e. 4), so they could form analogue molecules in a living organisms.
Yesterday, NASA researchers discovered an actual biological substitution along the same the lines. The six basic building blocks of life on Earth are Carbon, Hydrogen, Oxygen, Phosphorus and Sulfur.
Researchers studying Mono Lake in California (pictured above) discovered an organism - GTAJ-1 - a member of the Gammaproteobacteria group, that substitutes Arsenic for Phosphorus in its cell components. Read the article here. This is pretty interesting as for most life forms, Arsenic is a highly toxic chemical, whereas for this little sucker Arsenic is vital to its DNA and RNA and other mechanisms of life.
Maybe someone exploring the depths of the ocean will find Spock's rock-creature? Can't wait to find out.
Has anyone else come across any weird life forms recently? (And I'm not talking about in your refrigerator:))