The findings are based on a new report by the NRC called “The Limits of Organic Life in Planetary Systems”, which was developed by the NRC Committee on the Limits of Organic Life in Planetary Systems and the NRC Committee on the Origins and Evolution of Life.
The report states that looking for extraterrestrial life within the universe based solely on how life formed on the Earth—“a liquid water biosolvent, carbon-based metabolism, molecular system capable of evolution, and the ability to exchange energy with the environment”—is a very limited, and possibly defeatist, approach.
Instead, the authors of the report, headed by committee chairperson and U.S. oceanographer John Baross, from the University of Washington at Seattle, recommends that the search for ET life should be widened to consider life with alternative biochemistries to that of life on the Earth.
One of the highlights of the report, and the one that dramatically states the problem with current alien searches, is, "no discovery that we can make in our exploration of the solar system would have greater impact on our view of our position in the cosmos, or be more inspiring, than the discovery of an alien life form, even a primitive one." [Article: "Life Elesewhere in solar system could be different from life as we know it"]
The committee pointed out, for instance, that the exploration of the planet Mars is concentrated on looking for places where liquid water resides—which goes along with the idea of where life is found on the Earth. However, they emphasize that liquids such as ammonia, methane, and formamide could also be the building blocks for life under certain circumstances. In one instance, such liquids may exist in the interior of Titan, one of the moons of Saturn.
Baross comments: "It is critical to know what to look for in the search for life in the solar system. The search so far has focused on Earth-like life because that's all we know, but life that may have originated elsewhere could be unrecognizable compared with life here. Advances throughout the last decade in biology and biochemistry show that the basic requirements for life might not be as concrete as we thought." [Article: "Life Elesewhere in solar system could be different from life as we know it"]
The report concludes, “Nothing would be more tragic in the American exploration of space than to encounter alien life and fail to recognize it.”
The entire report, published Friday, July 6, 2007, can be read online from the NRC webpage: http://www.nap.edu/catalog/11919.html.