Key scientific questions and key investigations from the first international conference on Martian phyllosilicates.

Minerals and their occurrences can tell us about the chemistry, pressure, and temperatures of past environments on Mars and thus allow inferences about the potential for habitability. Thanks to recent space exploration, a new vision is emerging wherein Mars hosted environmental conditions of potential astrobiological relevance. This epoch is identified by the presence of phyllosilicate-bearing deposits, which are generally contained in very ancient basement rocks. In October 2008, over 100 planetary scientists representing 11 countries met in Paris to assess and discuss the relevance of martian phyllosilicates. The conference was structured to promote the discussion and debate of key scientific questions and key essential investigations. The purpose of this report is to document the current state of knowledge related to martian phyllosilicates and to ascertain which questions remain to be addressed: What are the basic characteristics of the phyllosilicate minerals on Mars? What are the genetic mechanisms by which phyllosilicate minerals have formed on Mars? What is the relationship between the phyllosilicate minerals observed in martian meteorites and those detected from orbit? What are the implications of phyllosilicate-bearing rocks for the development of prebiotic chemistry and the preservation of biosignatures? The most promising investigations to address these questions are presented.