Mars Sample Return from Meridiani Planum

The NASA Mars Exploration Program has four main goals: (i) determine if life ever arose there, (ii) understand the processes and history of its climate, (iii) determine the evolution of its surface and interior, and (iv) prepare for human exploration of Mars. These goals are embodied in the NASA Mars exploration strategy Follow the Water. Current Mars exploration tactics for lander missions build on knowledge gained by prior orbital investigations; the science rationale for choosing landing sites is based on the current best interpretation of the geology. A future Mars sample return mission will greatly exceed in cost typical lander missions because of the need to design for return to Earth and the infrastructure needed on Earth to curate and process the samples safely and cleanly. Because of this added cost burden, expectations for science return are higher. There must be some prospect that the returned samples will allow for testing higher level hypotheses relevant to NASA's goals. Site selection must be based on knowledge gained from prior in situ measurements to enhance the prospects for successfully meeting these goals. I will argue that Meridiani Planum should be that site.