In this 6th session of the internet-based live lectures between Universities and Institutes, Dr Frances Westall discusses the environmental conditions on early mars that were conducive to the emergence of life on the planet. Moreover, microbial-scale habitats were to those on early Earth, suggesting that early life on Earth may have been similar to early life on Mars. Thus, studies of the remains of early terrestrial life are useful in providing information on the nature of early life, its signatures and its distribution, and this information can be transposed to Mars to provide guidelines for what to look for, where and how. Instruments on in situ missions, however, have size, mass and data limitations that make it difficult to detect all the potential traces of martian life in situ. Definitive identification of life in martian rocks will probably require samples to be returned to Earth where sophisticated techniques can be used to investigate the various physical, organics and metabolic biosignatures of small, simple chemotrophic life forms.
