Alien life may be unrecognizable

Extraterrestrial life may well be so weird we would not immediately recognize it, and scientists looking for alien life should be seeking the unfamiliar as well as the familiar, experts advised Friday.

NASA’s current approach to “follow the water” works if the assumption is that life everywhere is just like life on Earth -- based on water, carbon and DNA, they said.

But the “life as we know it” approach could easily miss something exotic, the National Academy of Sciences panel said.

“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 looking for some obvious life form,” said John Baross, professor of oceanography at the University of Washington in Seattle, who chaired the committee.

The space agency commissioned the report from the National Research Council, one of the independent National Academies set up to advise the federal government on scientific issues.

The panel of biochemists, planetary scientists, geneticists and other experts considered all the possible ways that life could arise and exist.

As a biochemist, 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, he said.

NASA might also think about returning to some of the more promising places in our own solar system to look for evidence of life, the committee said. They include Saturn’s moons Titan and Enceladus and even steamy Venus.

“The exploration that could lead to a novel life form ... would be the most profound discovery ever made,” Baross said.

Stumbling past it, or worse, destroying it because it did not look like life, would be an equally profound tragedy, he said.