posted 01-14-2009 08:58 PM               

Alien microbes living just below the Martian soil are responsible for a haze of methane around the Red Planet, NASA scientists believe.

posted 01-14-2009 09:02 PM               

NASA will hold a science update at 2 p.m. EST, Thursday, Jan. 15, 2009, to discuss analysis of the Martian atmosphere that raises the possibility of life or geologic activity.

posted 01-15-2009 01:31 PM               

Discovery of Methane Reveals Mars Is Not a Dead Planet

A team of NASA and university scientists has achieved the first definitive detection of methane in the atmosphere of Mars. This discovery indicates the planet is either biologically or geologically active.

The team found methane in the Martian atmosphere by carefully observing the planet throughout several Mars years with NASA's Infrared Telescope Facility and the W.M. Keck telescope, both at Mauna Kea, Hawaii. The team used spectrometers on the telescopes to spread the light into its component colors, as a prism separates white light into a rainbow. The team detected three spectral features called absorption lines that together are a definitive signature of methane.

"Methane is quickly destroyed in the Martian atmosphere in a variety of ways, so our discovery of substantial plumes of methane in the northern hemisphere of Mars in 2003 indicates some ongoing process is releasing the gas," said Michael Mumma of NASA's Goddard Space Flight Center in Greenbelt, Md. "At northern mid-summer, methane is released at a rate comparable to that of the massive hydrocarbon seep at Coal Oil Point in Santa Barbara, Calif." Mumma is lead author of a paper describing this research that will appear in Science Express on Thursday.

Methane, four atoms of hydrogen bound to a carbon atom, is the main component of natural gas on Earth. Astrobiologists are interested in these data because organisms release much of Earth's methane as they digest nutrients. However, other purely geological processes, like oxidation of iron, also release methane.

"Right now, we do not have enough information to tell whether biology or geology -- or both -- is producing the methane on Mars," Mumma said. "But it does tell us the planet is still alive, at least in a geologic sense. It is as if Mars is challenging us, saying, 'hey, find out what this means.' "

If microscopic Martian life is producing the methane, it likely resides far below the surface where it is warm enough for liquid water to exist. Liquid water is necessary for all known forms of life, as are energy sources and a supply of carbon.

"On Earth, microorganisms thrive about 1.2 to 1.9 miles beneath the Witwatersrand basin of South Africa, where natural radioactivity splits water molecules into molecular hydrogen and oxygen," Mumma said. "The organisms use the hydrogen for energy. It might be possible for similar organisms to survive for billions of years below the permafrost layer on Mars, where water is liquid, radiation supplies energy, and carbon dioxide provides carbon. Gases, like methane, accumulated in such underground zones might be released into the atmosphere if pores or fissures open during the warm seasons, connecting the deep zones to the atmosphere at crater walls or canyons."

It is possible a geologic process produced the Martian methane, either now or eons ago. On Earth, the conversion of iron oxide into the serpentine group of minerals creates methane, and on Mars this process could proceed using water, carbon dioxide and the planet's internal heat. Although there is no evidence of active volcanism on Mars today, ancient methane trapped in ice cages called clathrates might be released now.

"We observed and mapped multiple plumes of methane on Mars, one of which released about 19,000 metric tons of methane," said co-author Geronimo Villanueva of the Catholic University of America in Washington. "The plumes were emitted during the warmer seasons, spring and summer, perhaps because ice blocking cracks and fissures vaporized, allowing methane to seep into the Martian air."

According to the team, the plumes were seen over areas that show evidence of ancient ground ice or flowing water. Plumes appeared over the Martian northern hemisphere regions such as east of Arabia Terra, the Nili Fossae region, and the south-east quadrant of Syrtis Major, an ancient volcano about 745 miles across.

One method to test whether life produced this methane is by measuring isotope ratios. Isotopes of an element have slightly different chemical properties, and life prefers to use the lighter isotopes. A chemical called deuterium is a heavier version of hydrogen. Methane and water released on Mars should show distinctive ratios for isotopes of hydrogen and carbon if life was responsible for methane production. It will take future missions, like NASA's Mars Science Laboratory, to discover the origin of the Martian methane.

The research was funded by the Planetary Astronomy Program at NASA Headquarters in Washington and the Astrobiology Institute at NASA's Ames Research Center in Moffett Field, Calif. The University of Hawaii manages NASA's Infrared Telescope Facility.

posted 01-16-2009 04:44 PM               

I know NASA has been looking for a long time. But this is the first time that we have something to measure. The discharge of methane gas and the possibility of an ecosystem effected by seasonal changes.

posted 01-17-2009 12:56 PM               

quote:

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Originally posted by Lou Chinal:
I know there's only a 50-50 chance that there is life on Mars, but the implications are staggering.

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posted 04-02-2019 11:27 AM               

In Nature Geoscience on Monday (April 1), scientists working with the European Space Agency’s Mars Express orbiter reported that in the summer of 2013, the spacecraft detected methane within Gale Crater, a 96-mile-wide depression near the Martian equator.

That is noteworthy, because NASA’s Curiosity rover has been exploring that region since 2011, and in the summer of 2013 it, too, measured a marked rise of methane in the air that lasted at least two months...

The presence of methane is significant because the gas decays quickly. Calculations indicate that sunlight and chemical reactions in the thin Martian atmosphere would break up the molecules within a few hundred years, so any methane detected must have been created recently.

It might have been created by a geological process known as serpentinization, which requires both heat and liquid water. Or it could be a product of life — specifically methanogens, microbes that release methane as a waste product. Methanogens thrive in places lacking oxygen, such as rocks deep underground and the digestive tracts of animals.

Even if the source of the methane turns out to be geological, the hydrothermal systems that produce the emissions would still be prime locations to search for signs of life.

posted 06-22-2019 11:08 AM               

The data arrived back on Earth on Thursday, and by Friday, scientists working on the mission were excitedly discussing the news, which has not yet been announced by NASA.

"Given this surprising result, we've reorganized the weekend to run a follow-up experiment," Ashwin R. Vasavada, the project scientist for the mission, wrote to the science team in an email that was obtained by The Times.

The mission's controllers on Earth sent new instructions to the rover on Friday to follow up on the readings, bumping previously planned science work. The results of these observations are expected back on the ground on Monday.

posted 06-22-2019 03:52 PM               

While increased methane levels measured by Curiosity are exciting, as possible indicators for life, it's important to remember this is an early science result. To maintain scientific integrity, the science team will continue to analyze the data before confirming results.

We don't yet know where methane on Mars comes from. A leading idea is that methane on Mars is being released from underground reservoirs created by past biology. But sometimes, methane is a sign of geology rather than biology. Learn more.