Life, not as we know it: Were NASA's Viking landers testing for the wrong thing?
Credit: NASA
CHICAGO: A 'shadow biosphere' of 'weird life' – unrelated to life as we know it – might exist on Earth, giving new insight into how common life is elsewhere in the universe, astrobiologists say.
Finding life that doesn't fit with the types we already know would be a strong indication that life developed more than one time here on Earth, increasing the chances of finding it elsewhere, said Paul Davies, an astrophysicist at Arizona State University in Tempe.
But nobody has ever seriously searched for microorganisms - or any form of life - different from the carbon-based, DNA-centred type of life about which we have long known.
Unique biochemistries
If we do look, Davies said, "It's entirely feasible that we'll find a shadow biosphere," he told reporters at the annual meeting of the American Association for the Advancement of Science (AAAS) in Chicago.
"Our search for life [has been] based on our assumptions of life as we know it. Weird life and normal life could be intermingled, and filtering out the things we understand about life as we know it from the things we don't understand is tricky."
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 was under their noses.
"When you don't know what you're looking for or what it'll look like, you have to come up with a whole scientific method for how to go about [looking for] it," added Steven Benner, a Fellow at the Foundation for Applied Molecular Evolution and The Westheimer Institute for Science and Technology in Gainesville, Florida.
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. Davies 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.
Piggybacking on a meteorite
If we do discover exotic life unrelated to ours, it might not have developed here, Davies said. Instead, it might have originated elsewhere, then hitchhiked to Earth by piggybacking on a meteorite.
But it doesn't matter where it originated, Davies argued, because it's still an indication that life has cropped up from scratch in more than one place.
"If it's happened more than once in the Solar System, then the Universe will be teeming with life," said Davies.
Scientists assign a probability to the possibility of life elsewhere in the universe on a scale of 0 to 1, with 0 being no chance to 1 being a 100 per cent likelihood. "We'd like to think it's 1, but who knows," said Davies.
Human evolution?
If you cannot find a fault in a theory then more than likely the theory is at fault.
As we advance intellectually as a society then does the veil shielding our eyes drop.
It's only a matter of time till we discover intelligent alien life and it will be overwhelming to realise we were always within grasp of the accomplishment.
Euty.
Original paper here
precedings.nature.com/documents/1482/version/1
well worth reading
Shadow biosphere
Thanks for the link mate, that's tops. Very interesting indeed!
What if?
Perhaps life on Earth had several starts that merged?
Did all our current
Did all our current scientists kick start their intellects by watching star trek? Hope they find what they are seeking......most of our present thinking parameters are too narrow....we need more generalists like Darwin to really think outside the box.
What to look for
There are countless possibilities about life elsewhere in the Universe. The main problem I feel is that if life in some form is discovered very alien to our understanding is this.
If it not life as we know it, we would not recognise it as life at all. Just a thought.
On Life As We Don't Know It
Hail Eris!
I've been thinking about this for months, actually. It's quite possible that "weird (intelligent) life" has arisen here multiple times (and either left or died out, or changed into something which could remain without further need of finite resources, assuming they had any such need in the first place) over the past 2-3 billion years, and some of them may have hung around (or returned) to become our gods/angels/demons/etc. It would, at least, explain the persistence with which belief in deities and spirits has cropped up in so many cultures, and shed some light on how we came up with the idea to build the Pyramids of the Mayans and Egyptians, and Angkor Wat (all of which were major undertakings, requiring massive bureaucracies to coordinate the architects and workers, years of planning, and utterly unreal taxation to pay for everything -- even if slave labour was used, slaves still need food, clothing, and shelter -- people just don't go to this much trouble for someone's wacky ideas about astronomy, and there are much easier ways to honour one's deities which still call for a lot of blood and sweat...but I digress)...Also, it would be interesting to square this with the "DreamTime" of the Australian aborigines.
Snarky