Possible existence of microbes on Mars

Source: China Daily | 01-17-2009 09:37

BEIJING, Jan. 17 -- Plumes of methane in the atmosphere of Mars provide evidence of the possible existence of microbes living below the Martian surface that produce the gas as some do on Earth, US scientists said on Thursday.

A full circle panoramic view of Mars taken by NASA's Phoenix Mars Lander is shown in this undated handout photo released to Reuters July 31, 2008. (Xinhua/Reuters Photo)

The methane likely was produced either by water reacting with hot rock below the surface or by living microorganisms as a waste product, they said during a NASA news briefing. The scientists said the evidence does not suggest the methane was brought to Mars by an object like a comet.

"This is exciting because we have evidence that we need to think about in terms of the possibilities of life on Mars," Indiana University scientist Lisa Pratt said.

"It's prudent that we begin to explore Mars looking for the possibility of a life form that's exhaling methane."

Scientists have been eager to determine whether Mars, the fourth planet from the sun and Earth's neighbor, had conditions in the past or present to support life. The new observations, made by using telescopes in Hawaii, did not directly detect life but found tantalizing evidence suggesting it was possible.

The scientists said if methane is coming from microbes, they likely live far below the frigid surface at depths warm enough for liquid water to exist. Liquid water is considered one of the essential ingredients for life. Water is known to exist on Mars. Robot rovers have sampled ice from the surface.

The scientists found substantial plumes of methane in the northern hemisphere of Mars in 2003 and called it the first definitive detection of the gas on the Red Planet.