Will we also colonize Earth microbes on Mars?

William Atkins
Monday, 23 June 2008 00:14

Science - Space

The report states, “Recent spacecraft and robotic probes to Mars have yielded data that are changing our understanding significantly about the possibility of existing or past life on that planet. Coupled with advances in biology and life-detection techniques, these developments place increasing importance on the need to protect Mars from contamination by Earth-borne organisms.”

The abstract of the PREVCOM report “… recommends that NASA treat all direct-contact missions as belonging to a new category, category IVs. (“s” here stands for “special,” given by COSPAR definition to be “a region within which terrestrial organisms are likely to propagate, or a region which is interpreted to have a high potential for the existence of extant martian life forms.”)"

"PREVCOM also recommends that category IVs missions satisfy (at a minimum)  requirements that are more rigorous than Viking pre-sterilization levels, but less rigorous that Viking post-sterilization levels. Specifically, such missions should satisfy Viking post-sterilization bioload reduction levels (understood as areal measurements)  on all exposed surfaces of the spacecraft, i.e. surfaces that freely communicate with the martian atmosphere or surface."

"The full report includes a total of 17 distinct recommendations. As one of these, PREVCOM suggests the need for international discussions and consideration of whether “planetary protection” policies should be extended beyond the protection of science investigations alone to include the protection of a possible martian biosphere itself.”

The entire report is found at the National Academies Press wesite “Preventing the Forward Contamination of Mars.”

As of 2008, NASA is still assessing its techniques for sterilizing spacecraft going to Mars. Improvements have been made in the processes, but they are still far from perfect. The recommendations made by the PREVCOM members are not expected before 2016.

The Mars Science Laboratory is expected to be launched to Mars in September 2009. It is expected to land on Mars in the July-September 2010 timeframe. The rover will be three times as heavy and twice as wide as the rovers Spirit and Opportunity, who are currently roving on the sursface of Mars.

NASA scientists with the Phoenix Mars Lander mission already think they have found ice on Mars. If scientists find signs of possible past or current life on Mars, serious issues will confront mission planners of new projects to Mars.

They will have to contend with the distinct possibility of contaminating a world once holding life or presently holding primitive forms of life. That is, unless contamination measures are instituted by NASA and other space agenices around the world, to prevent such contamination from happening on Mars.