Searching for Alien Life Having Unearthly Biochemistry

摘要

NASA's astrobiology program should include a search for exotic life forms having an unearthly biochemistry in our solar system and beyond. Exotic life forms may have biochemistry totally unlike that of Earth organisms. Alien life forms may be disturbingly different and nearly unrecognizable, or their independent origin may be revealed only by detailed biochemical analysis. Other solvents than water may support exotic life, and other elements than carbon may form life-enabling chain molecules. Exotic life forms may not be restricted to planets in the 'habitable zone' defined by Earth-like conditions.