Posts Tagged ‘Astrobiology’

Yesterday I attended to a short session that I really enjoyed: 16 d.- ‘Exobiology: are any terrestrial extremophiles plausible proxies for hypothesized microbial life on Venus, Mars, or the Jovian planets and their satellites (e.g., Titan, Europa, Callisto, Enceladus)?
Although all contributions to that session were really good, I would like to highlight the keynote talk of Davis Des Marais, from NASA Ames Research Center. I really loved it. He showed us a summary about the stage in which the ‘Search for Life’ studies in Mars are. During the last decade, our knowledge of the geology of Mars has increased exponentially. There have been many space probes (Mars Global Surveyor, Mars Odyssey, Mars Express, Mars Reconnaissance Orbiter) which have produced an amazing amount of information about the geology of the Red Planet from the orbit, not only using high resolution imaging, but also IR spectroscopic techniques (to provide data about the surface mineralogy) and gamma ray spectrometry, (confirming the presence of near-surface ice water below the polar and template areas). At the same time, four landers [Mars Pathfinder (1997); the twin Mars Exploration Rovers Spirit and Opportunity (2004 to present) and the Phoenix lander (2008)] have carried out a characterization of different landing sites, finding evidences that imply water flows, hydrothermal activity, weathering, etc. in the remote past.
The last decade of Martian exploration has ‘followed the water’ approach to show us the areas in Mars that were potentially appropriate for the development and sustainability of life in the past. Now the next step is to ‘follow the life’: a new generation of rovers with advanced instrumentation that will be capable of finding signatures of life is being designed, built and tested prior to be sent to Mars in the years ahead. The question is: where to send them? We need to find landing sites that meet two requirements: 1) the areas need to be safe for landing; 2) they need to be interesting from the astrobiological point of view, that is, we need potential places that could harbour present or past microbial life.
In his talk, Davis Des Marais showed us candidate landing sites (Mawrth Valles, Nili Fossae, the Holden crater, etc.) that would be suitable for new missions like the Mars Science Laboratory (NASA) or ESA’s Exomars. If life exists in these areas, it has to be located in the near-surface and will need both water ice and inorganic nutrients. Future missions will be sent to the best candidate places to carry out an exciting task, giving us the possibility of answering many important questions that have been unresolved for decades.


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