Back is the future: returning samples from Mars for analysis on Earth
Seeking evidence of life in the solar system will be partly the search for organic signatures in rock matrices. The search for organic matter is common to petroleum exploration on Earth and life search missions to Mars. Despite some commonality between investigations into life records on Earth and Mars, there are also significant differences. Favourable organic concentrations in petroleum source rocks are much higher than those needed for life-search targets on Mars. Choosing samples for collection on Mars for return to Earth requires more care at earlier stages than needed for collection of samples on Earth. During and after collection, samples of Mars must be protected from organic contamination that could confuse their potentially weak and poorly understood signals. While operations on Mars provide effectively unlimited samples but with limited instrumentation, analysis on Earth involve constrained amounts of returned samples but access to the world’s best analytical capabilities. Returning samples from Mars also presents the potential for historical firsts including new technologies and important preparations for the eventual human exploration of the Red Planet.