Hope to find life on Mars reborns with the Phoenix

Comment by Susana Direito (Faculty of Sciences and Technology, New University of Lisbon, Portugal) on behalf of the Portuguese Astrobiology Working Group (PAWG) coordinated by Prof. Maria Eugénia Webb, the Portuguese representative at the European Astrobiology Network Association.
This group is currently studing the 'Mars Exobiological Potential' as part of MAGIC project (Mars Atmospherical Geophysical and ExobIological Characterisation), financed by the FCT (Portuguese Foundation for Science and Technology ‘Fundação para a Ciência e Tecnologia’) and with the Recognised Cooperating Laboratory status for the Mars Express mission.

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Every mission to Mars brings further hope in finding extinct or extant life on this planet.
PAWG is currently studying the martian exobiological potential and we are therefore very curious about the results of Phoenix Mars mission.

There are very important aspects to this mission: the fact that it will be the first time a mission will have direct contact with Martian ice and the fact it’s planned to bring further understanding on martian water history, and as we know, water in liquid state is one of the pre-requisites for the existence of life.

In addition, the previous methane detection in the martian atmosphere generated an interesting discussion on the possibility of life on our neighbour planet. The necessity to prepare martian space missions that are designed to corroborate this methane detection and possibly detect longer hydrocarbons and other complex organic molecules become thus of great importance.

This 'spectrum' was recorded in the areas where the methane concentration is higher. The black line shows the measured spectrum, compared to the computed methane spectrum (red line) and indicating 35 parts per billion of methane in the atmosphere. In other areas, the measured average of methane at Mars is only 10 parts per billion. Credits: ESA/ASI/PFS team. More information here.

For example, the study of isotopes, such as the measurement of the isotopic ratio 13C/12C of martian methane may help to clarify its origin. Indeed, living organisms biologically ‘fix’ the lighter isotope, carbon 12, over the heavier carbon 13. On the other hand, methane that is generated by abiogenic processes shows preference for the carbon 13 isotope.

Phoenix to be launched in August 2007 will land near the martian north polar permanent ice cap and will carry several instruments. One of them, TEGA - Thermal and Evolved Gas Analyzer built by the University of Arizona and University of Texas, is a high-temperature oven and a mass spectrometer instrument that will be capable of measuring isotopes ratios for several elements (carbon, hydrogen, nitrogen and oxygen). The instrument's ovens will heat slowly the soil and ice samples at a constant rate. A process that will reveal the evolution of phases of the materials: from a solid to a liquid to a gas phase. When the temperature of the ovens reaches 1000ºC, the volatile sample materials are vaporized and transported to a mass spectrometer where they will be analyzed.

The TEGA Engineering Qualification Model matrix assembly shown without the manifold. Image Credit: NASA/UA. More information here.

Therefore, we expect that TEGA, besides being capable of verifying the presence of water in solid phase and measure humidity, will be also capable of identifying altered minerals (ex. carbonates), hydrocarbon molecules and other very significant organic molecules which are of great importance in our quest to find life.

As a final note, and in the name of PAWG, we want to salute and wish good luck to the Phoenix team.