Earth May Harbor a Shadow Biosphere of Alien Life

An anonymous reader sends us to Cosmos Magazine for a speculative article arguing that a 'shadow biosphere' may exist on Earth, unrelated to life as we know it. If such non-carbon-based life were found here at home, it would alter the odds for how common life is elsewhere in the universe, astrobiologists say. "The tools and experiments researchers use to look for new forms of life — such as those on missions to Mars — would not detect biochemistries different from our own, making it easy for scientists to miss alien life, even if [it] was under their noses. ... Scientists are looking in places where life isn't expected — for example, in areas of extreme heat, cold, salt, radiation, dryness, or contaminated streams and rivers. [One researcher] is particularly interested in places that are heavily contaminated with arsenic, which, he suggests, might support forms of life that use arsenic the way life as we know it uses phosphorus."

Comments

So something which we can't define...

[MichaelSmith]

...may exist on Earth but we won't be able to look for it until we define it.

Sounds pretty clear to me. Maybe rocks are intelligent. How would we know? Has anybody thought to ask?

Carbon-based for a reason

[Shrike82]

Interesting theory, but I seem to remember my biology teacher discussing silicon-based life, and how it was much less likely to develop as carbon atoms produced much more stable molecules, especially on planets like Earth with water and nitrogen/oxygen atmospheres. Carbon-based life just "works" better on Earth.

On planets with radcially different environments there's probably a lot of potential for life that's totally different from ours, but I think it's fairly unlikely for us to discover it here.

not buying it.

[timmarhy]

some of these arguments often sound plausible until you examine the mechanics for life. water for instance, has unique properties not shared by any other compound - the ability to be neutral, liquid at reasonable temps and be able to transport other elements. the same goes for carbon. nothing else is going to be able to put together a tangible life form.

They're Made of Meat

[moshez]

"They're made of meat."

"Meat?"

http://home.earthlink.net/~paulrack/id82.html

"Alien"?

[PriceIke]

"Alien" means "not from here." If our planet harbors a resident life form which we're not aware of, that doesn't make them alien. It just makes us ignorant.