How Habitable is Mars?

Assessing the habitability of Mars has been an objective of the scientific community for a long time, but it has recently become a sustained focus in light of data being returned from the planet and growing knowledge about life in extreme environments. The Curiosity rover on the Mars Science Laboratory (MSL), one of NASAs flagship missions, analyses since August 2012 the Martian environment to assess whether Mars could have supported life. After more than 5 years of operations on Mars the rover Curiosity has acquired an unprecedented data record of near surface measurements providing an invaluable ground truth about the environmental conditions on Mars. In particular Curiosity has found: (i) evidences for liquid water conditions on Mars; (ii) preserved indigenous organic molecules in mudstone soil samples; (iii) indigenous fixed nitrogen which may provide a biochemically accessible source of nitrogen for life; (iv) manganese oxides on the surface; and (iv) also detected methane in the atmosphere at variable concentrations throughout the mission. These discoveries, together with other from previous and current missions to Mars, have sparked speculation about the past or present existence of life on Mars; and they have opened many scientific questions and challenges. Moreover, the future human exploration of Mars requires access to in-situ resources. Space agencies are requesting, for the first time ever, for ideas on In-situ Resources Utilization (ISRU) instruments that can efficiently extract key resources (water, oxygen, etc.) from Mars. But the international efforts of Mars surface exploration require a coordinated effort to respect the Planetary Protection protocols and to avoid the forward contamination of Mars. This in turn requires, updating our knowledge about the Martian habitability conditions.

In this talk I will revise, based in our current understanding of the environmental conditions on Mars, and definitions of life, the quest of Martian habitability.