Will we also colonize Earth microbes on Mars?

William Atkins
Monday, 23 June 2008 00:14

Science - Space

According to a New Scientist article, NASA researchers found one hundred species of terrestrial bacteria in the assembly room of the Phoenix Mars Lander.

Inside the room where the Phoenix Mars Lander was assembled--at the Jet Propulsion Laboratory in Pasadena, California, U.S.A.--esearchers found “at least 26,000 cells per square metre and 100 species of bacteria….” [New Scientist (June 14-20, 2008, page 4, subscription required): “Colonising Mars“]

In particular, one bacteria called Bacillus pumilus is found to be extremely resilient to the normally deadly effects of ultraviolet (UV) light on bacteria.

Parag Vaishampayan, one of the NASA researchers, stated, “This is the hardiest organism we have ever isolated.” [New Scientist]

Specifically Vaishampayan and fellow-researcher Kasthuri Venkateswaran tested whether Bacillus pumilus and other bacteria could survive a journey to Mars and withstand the rigors of the environment on Mars.

The bacteria were placed in chambers that simulated the temperature, air pressure, and UV radiation on Mars. Of the 100 species of bacteria tested, three died within five minutes of the test.

However, then the researchers added to the chamber some soil from the Atacama desert (in South America between the Andes Mountain and the Pacific Ocean) and a Hawaiian volcano, some of the bacteria were able to survive, supposedly because they are able to shield themselves from the radiation.

Another member of the team, Rocco Mancinelli, stated, “[The results] suggest that yes, you’ll get some killing, but not 100 per cent sterility.” [New Scientist]

The findings of the NASA researchers were presented at the annual meeting of the American Society for Microbiology, which was held in Boston, Massachusetts, U.S.A., between June 1-5, 2008.

Information about earlier studies on the exploration and possible contamination of Mars follow on the next page.