Wired Magazine-- In the search for extraterrestrial life, some scientists say we’re focusing too much on finding signs of existence as we know it, and in the process, we may be missing more strange forms of life that don’t rely on water or carbon metabolism. Now researchers from Austria have started a systematic study of solvents other than water that might be able to support life outside our planet. They’re hoping their research will lead to a shift in what they call the “geocentric mindset” of our attempts to detect extraterrestrial life.
“With our current measurement strategy for life on other planets, we will only be able to detect life which shares most of its parameters with terrestrial life,” astrobiologist Johannes Leitner of the University of Vienna, who presented his research Friday at the European Planetary Science Congress in Germany, wrote in an e-mail. “Presently we will not be able to detect exotic life, because we have no idea of its potential properties and by this, our probes to planetary surfaces do not carry instruments which can look for something exotic.”
For instance, Leitner said, we can send rovers to Mars carrying antibodies that detect traces of chemicals and bacteria that would indicate life. But because we can only make antibodies to known substances, this method will be limited to finding Earth-like life.
“When we try to find a definition for life, in most cases, such a definition is more a summary of the specific properties of terrestrial life,” Leitner said. Because life on Earth requires water, most of the search for extraterrestrial life thus far has focused on the “habitable zone,” or the relatively narrow region around a star where liquid water could exist.
But while water is liquid only between zero and 100 degrees Celsius, other solvents are liquid over a much larger temperature range. For instance, because ammonia stays liquid at a lower temperature, an ocean of ammonia could exist on a planet much further from its host star. By exploring the properties of more potential solvents, such as sulfuric acid and formamide, the researchers hope to expand the potential life-supporting zone.
I'm so excited that the science community is finally thinking outside the box created by earlier scientists. I've often thought it's even possible that life forms could have evolved that had no need for physicality-living amongst us in an almost ghostly way. We need to redefine what "life" is.
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