Here are the edited conference proceedings (.pdf) of a roundtable discussion among leading astrobiologists, to relate atrobiology goals to planning in planetary sciences: “The Next Phase in Our Search for Life: An Expert Discussion”:
Moderator: Christopher P. McKayParticipants: Dirk Schulze-Makuch, Penelope Jane Boston, Inge L. ten Kate, Alfonso F. Davila, and Everett Shock
Some interesting stuff here:
PJB: I served for about three years on the National Research Council (NRC) Complex Panel and just about everybriefng we received from anyone within the planetary programs always included the life question, because it is something that’s on everyone’s mind, whether they do this kind of science or not.
This question is one that I have struggled with a lot. To scope out the physical and chemical environment is really inextricably bound to the search for life, and it is true that we have focused a great deal on that because, truthfully, it is a lot easier to measure a physical parameter on Mars than it is to, ‘‘search for life,’’ because that latter question is so open-ended. We have a very poor constraint set on what we actually mean by the term ‘‘life,’’ and searching for biochemistry and macromolecules that look just like those on Earth is not an efficient approach. It is much more challenging to imagine how we would actually design a real life detection mission.
So people are tempted to shy away from coming to grips with that very difficult epistemological question, which is:
How do we know we have succeeded if we are anticipating looking for life that might be either reasonably different from us or radically different from us?
This was a dilemma that was not successfully overcome with the Viking missions, as we all know. So we had a certain paradigm that informed those missions about what life would do and how it would behave, and the experiments were all designed to that set of precepts. It was the best that could be done then. I am not sure we could do that much better now because we need a design that is openended enough to allow us to really explore, and that openendedness is really anathema in terms of the way space missions are constructed and controlled. We have a real philosophical and methodological dilemma here about how to push in the direction of greater emphasis on actual life detection missions. (P. 4) (ASTROBIOLOGYVolume 11, Number 1, 2011)
Yes, it does help to know what we are looking for.