Y‐Mars: An Astrobiological Analogue of Martian Mudstone

Abstract NASA's Mars Science Laboratory mission has collected evidence of a long‐lasting habitable environment in the Sheepbed sediments of Gale Crater on Mars. The geochemistry of this mudstone suggests that the lake filling the crater in Mars' past had a neutral pH and low salinity and contained elements and redox couples required by life. We produced a geochemical analogue to the Sheepbed mudstone by mixing a collection of its primary minerals to match the X‐Ray diffraction data from Mars Science Laboratory. Here we describe the production of the Y‐Mars (Yellowknife‐Mars) analogue and characterize its properties, including the presence of background carbon, nitrogen, and sulfur. We highlight some of the unavoidable issues involved in making analogues, especially for astrobiological applications. The Y‐Mars analogue has a number of applications for astrobiological research, but more analogues are required to properly represent the diversity of Martian sedimentary contexts.