Methane on Mars: Could Be Farts from Microbe Life on Mars ?

NASA has found three discrete regions where Mars is releasing methane at this time.

Methane can only survive a short time in the atmosphere until it is destroyed by sunlight, and so its continued presence means it is being replenished.

“The production (of methane) is likely due to only one of two possibilities. The first is geochemistry, the second is biology. That raises much interest on which one is the dominant production mechanism.”

If the methane is produced by geological activity, it could either originate from active Martian volcanoes or from a process called serpentinisation.

The latter process occurs at low temperatures and occurs when rocks rich in the minerals olivine and pyroxene react chemically with water, releasing methane.

We’ve demonstrated there are regions of active (methane) release,” said Dr Mumma.

“What we’d really like to do is map the entire planet identifying all such regions of release and validating that some are reproducible from year to year.

“In addition, we’d like to map the gases being released to establish which of those are more likely biological in origin versus others that may be geochemical in origin.

“On this basis we could target several interesting sites for lander missions.”

Nasa’s Mars Science Laboratory (MSL) rover, due to launch to the Red Planet in 2011, will carry instruments that have the potential to distinguish between carbon in gases produced by biological activity and those with a geochemical origin.

Unequivocal determination may have to wait for the next rover mission after MSL as explained at Astrobiology Magazine.

Astrobiology Magazine Explains the Science
Although the amount of martian methane is small (10 parts per billion compared to 1,800 parts per billion on Earth), it appears to be concentrated in regions around the equator. Because these methane “clouds” only last a year before dispersing, the methane sources must be fairly localized and constant.

Microbes called methanogens produce this greenhouse gas as part of their metabolism. Onstott estimates that this localized generation is comparable to that of Earth’s Arctic permafrost, which is one of our planet’s main sources of this greenhouse gas.

The building blocks of methane (carbon and hydrogen) exist in different forms, called isotopes, that differ in mass. Geochemistry isn’t picky and will use whatever isotopes it finds to make methane. Life, however, prefers to consume lighter isotopes.

“Enzymatic processes work faster on compounds of lighter weight,” Onstott said.

In the case of methanogens, they will select molecules with hydrogen (rather than its heavier isotope deuterium) and carbon-12 (rather than the heavier carbon-13).

The result is that biogenic methane should be lighter than abiogenic methane.

One confounding factor is that organisms that eat methane may also inhabit Mars. These so-called methanotrophs have a preference for light-weight methane, thereby removing the evidence of methanogen activity.

The Mars Science Laboratory (MSL) — now scheduled to launch in 2011 — will carry such an optical spectrometer (the Tunable Laser Spectrometer, or TLS). This device may be able to measure the carbon isotope ratio in martian methane, but Onstott does not think it will be able to say unequivocally whether life or geology is the source.

For this reason, he and his colleagues are designing a special kind of optical spectrometer, called a cavity ring-down spectrometer (CRDS), that will be 1,000 times more sensitive than TLS. The CRDS works by illuminating an atmospheric sample with a laser whose frequency can be tuned to resonate with methane molecules of a particular isotopic configuration.

Although the CRDS is a mature technology, Onstott and his group need to develop a portable device that can reach a high sensitivity. They have already built a test version that weighs 70 pounds, about a fifth of what a typical mass spectrometer weighs.

The goal now is to make the instrument smaller and more compatible for space missions — such as the next rover mission after MSL.

“We plan to make modifications that will ensure it functions on Mars, where there’s lower pressure and lots of dust,” Onstott said.

About The Author

Add comment

E-mail is already registered on the site. Please use the Login form or enter another.

You entered an incorrect username or password

Sorry, you must be logged in to post a comment.


by Newest
by Best by Newest by Oldest

Thanks for details and research Michael.


Something to keep an eye on is the Taiwanese presidential elections for March 22, 2008 I have predicted that Ma Ying-jeou of the KMT will win. The KMT landslide legislative victory and most of the polls suggest that this is a safe prediction

The KMT got only 60% of the vote, which they always do. The DPP actually recieved its highest vote total ever. If you look at the votes over the last decade, the KMT-Blue vote has not gained a single vote since 1998, whereas the DPP has expanded by 800K votes in the legislative elections over the same period. You can't look at the seats, you have to look at the raw vote. It suggests the opposite -- that the Presidential election will depend on the turnout, and that it will close, just like the last two. My own view is that if turnout exceeds 80% and the number of invalid ballots returns to previous levels, Hsieh will beat Ma. I sure hope so. Ma is a spineless puppet of the party's hidebound anti-democracy leadership, a hopeless pro-China ideologue.

That said, everyone here thinks that Ma will win. That's the CW, which is ordinarily as wrong as can be, but the uncannily accurate election market at Political Uunivesity also has Ma ahead, so I tend to think thereis some merit in that view. The polls are a joke, they have Ma beating Hsieh by 25% or more, which is ridiculous -- they are all put out by pro-Ma papers. The KMT chairman, Wu Po-hsiung, yesterday claimed the party's internal polls have Ma ahead by 10%. This is the first election they've had a serious polling capability. It's hard to say how real that number is. He was making the point that Blues should not stay home because the outcome is foreordained. It might actually be closer than that.

The main difference with a KMT victory would be direct airplane flights between China and Taiwan and pretty much unrestricted investment from Taiwan into China.

Both men support these policies. On cross-strait issues there is little to choose between them. The main difference is actually domestic; Ma's policy is basically an LDP style debt-driven concrete-laden infrastructure boom. Not that the DPP is a whole lot better. Both parties are stuck with the completely corrupt and concrete-driven local political economy the KMT put together during martial law period.

It should also mean greatly reduced political and military tensions over Taiwan and China with the likely prospect of some kind of peace and unification talks at some point in the near future.

I hope not. Few here want to see Taiwan annexed to China. There is no need of that to achieve peace. China just needs to grow up, is all, and stop trying to annex a territory that was never part of any Chinese emperor's domain.

Tensions could be reduced any time, simply by China growing up on the Taiwan issue.

Positive results there seem likely to help the long term economic outlook for both Taiwan and China.

That outlook will be positive no matter who is elected. Our economy is booming -- 5.7% growth, #2 exporter to China. At home incomes are stagnant, because the KMT, which controls the legislature, has cut off the flow of public construction funding in a bid to pull incomes down and convince the public that the economy is bad. In a country where the media was balanced they couldn't get away with that....but this is Taiwan.

The belief so widely held here that "opening to China" (when we have $200 billion of investment there already) is a form of cargo cult economics... Taiwan already has access to the China market. What it needs is an overhaul of its educational institutions and further development of high tech sectors, and other things that China opening won't affect one iota.

On the sidebar of my blog I have links to some extensive numerical analyses of the election. Enjoy.