NASA is assessing support for a major look into the limits of organic life in planetary systems.

In the past, life detection experiments sent to other worlds have been criticized for being too geocentric -- based on the life here on Earth, also tagged as "terran" life.

"As the search for life in the Solar System expands it is important to study what exactly to search for," explains a document obtained by SPACE.com detailing the objectives of the proposed scientific study.

"This study will inform research program managers, policymakers, and mission designers on the possibilities for life on other solar system bodies. Further, during planetary protection exercises of NASA, questions concerning the possibility of non-terran life recur repeatedly. Remarkably little knowledge is organized that might shed light on the plausibility of bizarre life as a concern for planetary protection," the working document explains.

The new study outline notes that the search for signs of life -- present or past -- is an important goal of NASA's robotic solar system exploration programs. Ultimately, that search for life is also tied to astronomical projects designed to probe the workings of extra-solar planetary systems.

Looking at NASA's current search for life activities, including the "follow the water" strategy now apart of Mars exploration, are defensible, "given the absence of a general understanding of how life might appear if it had an origin independent of life on Earth," the study outline notes.

"Experiments in the laboratory, however, are suggesting that life might conceivably be based on molecular structures substantially different from those known in contemporary terran life. These results suggest that if life originated independently, even within our own solar system, it may have non-terran characteristics and, thus, not be detectable by NASA's in situ or remote-sensing missions designed explicitly to detect terran biomolecules or their products."

A hoped for by-product of the proposed new study is guiding the development of a new generation of life detection experiments -- investigations that can be done on-the-spot on planetary surfaces, or conducted on samples returned from other solar system bodies.

Overall, the programmatic goal of the study will be to identify research directions that will assess the likelihood of non-terran life and the potential cost needed to find it. "From this will come a recommendation whether the likelihood of finding non-terran life is sufficiently low that the possibility should be ignored, or sufficiently high that it should be pursued," the study outline concludes.

"This is the kind of work that should be supported, so we don't become too myopic," said Michael Meyer, Astrobiology senior scientist at NASA Headquarters in Washington, D.C. He could not comment directly about the proposed study, still being discussed and weighed by the space agency.

Meyer said that looking at the origin of life on Earth "has been an extremely difficult problem." The scientific community delving into the issue of life beyond Earth should expand their "thought space", he added, in terms of "what might be out there," he told SPACE.com.