* Science panel says alien search needs refinement
* Water "not necessarily" basis for life
* NASA "should return to our system to look for life"
EXTRATERRESTRIAL life may well be so weird we would not immediately recognise it, space experts said yesterday.
Scientists looking for alien life should be seeking the unfamiliar as well as the familiar, they said.
NASA's current approach to "follow the water" is logical assuming alien life is comparable to that on Earth - based on water, carbon and DNA - but the "life as we know it" approach could easily miss something exotic, the US National Academy of Sciences panel advised.
"The purpose of this whole report was to be able to look for life on other planets and moons with an open mind ... and not maybe miss some other life form because we are looking for some obvious life form," said John Baross, professor of oceanography at the University of Washington in Seattle, who chaired the committee.
The US space agency commissioned the report from the National Research Council.
The panel of biochemists, planetary scientists, geneticists and other experts considered all possible ways life can arise and exist.
Recent discoveries of extremophiles - organisms living in conditions of heat, cold and dark and using chemicals once thought incompatible with life - have changed ideas of where life can survive.
Prof Baross said lab experiments also showed water did not necessarily have to be the basis for life.
It might be possible for a living organism to use methane, ethane, ammonia or even more bizarre chemicals.
"We had some discussion about how weird to make this because there are so many concepts out here.
"There are so many theories about what life is and what could be a living system."
NASA and other groups are looking hard for extraterrestrial life.
Telescopes search for spectral signatures from other planets that might suggest water is on the surface.
Robots on Mars are seeking evidence of water, past or present.
"We wanted to actually think outside of that box a little bit and at least try to articulate some of the other possibilities besides water-carbon life."
They suggested NASA should return to some of the more promising places in our own solar system to look for evidence of life, such as Saturn's moons Titan and Enceladus, and even steamy Venus.
It baffles me that they didn't think of this before.
Quote:
NASA's current approach to "follow the water" is logical assuming alien life is comparable to that on Earth - based on water, carbon and DNA - but the "life as we know it" approach could easily miss something exotic, the US National Academy of Sciences panel advised.
"The purpose of this whole report was to be able to look for life on other planets and moons with an open mind ... and not maybe miss some other life form because we are looking for some obvious life form,"
07-08-2007, 11:23 AM
Aliens exist, but maybe unrecognisably weird
Linear Mode
