Methane discovery

Methane discovery hints at living Martian microbes

US scientists said, 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.

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

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. 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.

Methane is composed of four atoms of hydrogen bound to a carbon atom, and is the main component of natural gas. On Earth, methane is known as swamp gas and made by decaying plants or found in the burps, belches and other emissions of animals from termites to cattle and people.

Bacteria have been found on Earth that use hydrogen as energy and can turn carbon dioxide into methane.

The researchers wrote: "These communities thrive at 2-3 km (1.2 to 1.8 miles) depth in the Witwatersrand Basin of South Africa and have been isolated from the surface (and photosynthesis) for millions of years."

Their observations indicate an association between methane and both warmer temperatures and water, suggesting summer temperatures start some process, biological or geological. Its thin atmosphere is mostly carbon dioxide, with some nitrogen, carbon monoxide, trace amounts of oxygen and water vapor.