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Re: all-hail ME'THANE of Nili Fossae (2009 January 19)

Posted: Wed Jan 21, 2009 3:57 pm
by bystander
aristarchusinexile wrote:My other post was from Scientific American, quoted as such .. but I do agree with you that it is necessary to distinuguish possible from probable from certain.

Personally, I think the venting of methane on Mars after such a long period of surface inactivity indicates a definite certainty of methane creation below the surface at this time. If I was a gambler I would lay a large sum of money on it.
Your earlier post was not so much a quote of the article, as a paraphrase of it. (Here is a reprint of the article). In fact, your last statement (the statement Chris objected to) is found nowhere in the article.
aristarchusinexile wrote:Methane seems to declare the verdict .. that there is life on Mars .. which comes as no surprise whatsoever. Further, the presence of methane on Titan, in far larger abundance, seems to declare life on Titan as well.
The article, as I read it, seems to reach different conclusions than those you state.
SciAm wrote:...
In view of these obstacles, a biological explanation for methane is much less attractive on Titan than on Mars.
...
In summary, methane serves as the glue that holds Titan together in some mysterious ways. The presence of methane on Mars is equally intriguing, not the least because it evokes visions of life on that planet. Future exploration of both bodies will seek to determine whether they were ever habitable. Although life as we know it can produce methane, the presence of methane does not necessarily signify the existence of life.

Re: all-hail ME'THANE of Nili Fossae (2009 January 19)

Posted: Wed Jan 21, 2009 5:20 pm
by aristarchusinexile
Chris Peterson wrote:
aristarchusinexile wrote:Personally, I think the venting of methane on Mars after such a long period of surface inactivity indicates a definite certainty of methane creation below the surface at this time. If I was a gambler I would lay a large sum of money on it.
I'd be cautious with phrases like "definite certainty". I think most people believe the methane is coming from beneath the surface. But it's quite possible that somebody will propose a viable explanation for a surface effect. Soil chemistry on Mars is largely unknown.
Genuine Thanks, Chris. You're absolutely right. There may be an organism on the surface. Mould! Mould can survive long periods in space. Does anyone here know if moulds on earth create methane? Moulds, I think it has been said, are the largest living organism on our planet. What would moulds eat on Mars? Like you said, Chris, "soil chemistry on Mars is largely unknown." I would now bet on both methods of methane creation .. still believing Black Smokers exist in liquid water beneath the frozen ice.

Re: all-hail ME'THANE of Nili Fossae (2009 January 19)

Posted: Wed Jan 21, 2009 5:25 pm
by aristarchusinexile
bystander wrote: Your earlier post was not so much a quote of the article, as a paraphrase of it.
My first post on this topic in this thread were direct quotes, in quotation marks, not misquoted, and attributed. Naturally I did not quote the entire article, as I have been told copyright considerations on apod discourage such inclusions. See - I'm really trying to be a good fellow!

Oops - I correct myself - I see I may have deliberately paraphrased this one paragraph to avoid copyright problems - 'On earth, 90-95 percent of methane is biologic in origin. Volcanoes contribute less than 0.2% of earth's methane, and that amount may simply be venting methane created by organisms in the past.' The paragraph before and following this one were direct quotes.

Re: all-hail ME'THANE of Nili Fossae (2009 January 19)

Posted: Wed Jan 21, 2009 5:45 pm
by aristarchusinexile
From the Scientific American article -

"Tied up with these issues is the question of why organics seem to be missing from the surface of Mars. Even in the absence of life, meteorites, comets and interplanetary dust particles should have delivered organics over the past four and a half billion years. Perhaps the answer lies in Martian dust devils and storms and ordinary saltation (the hopscotching of windblown dust grains). These processes generate strong static electric fields, which can trigger the chemical synthesis of hydrogen peroxide. Being a potent antiseptic, hydrogen peroxide would quickly sterilize the surface and scrub out the organics. The oxidant would also accelerate the loss of methane locally from the atmosphere, thus requiring a larger source to explain the abundances observed in the Martian atmosphere."

Perhaps mould is not such a good bet after all .. swings me back to favouring the geothermal vents with their life forms.

Re: all-hail ME'THANE of Nili Fossae (2009 January 19)

Posted: Wed Jan 21, 2009 6:14 pm
by bystander
No matter, I posted a link to the article, people can read it for themselves if they are interested.

What say you, Art, Thane of Nili Fossae? Geo or Bio? It seems that Nili Fossae is one of the methane sources.

Mars Methane: Geology or Biology?
Space.com - January 15, 2009

Martian Methane Reveals the Red Planet is not a Dead Planet
NASA Mission Pages - Mars - January 15, 2009

Discovery of Methane Reveals Mars Is Not a Dead Planet
NASA PR 09-006 - January 15, 2009

Re: all-hail ME'THANE of Nili Fossae (2009 January 19)

Posted: Wed Jan 21, 2009 6:45 pm
by aristarchusinexile
Okay .. so the surface may be devoid of organic matter. However, what lies just below the surface? How thin are the sands covering Mars? Ground penetrating radar shows extensive riverbeds beneath the Sahara. The text accompanying the photo says the methane was being released during the summer months .. so warming of the surface layers is almost certainly a factor.

Re: all-hail ME'THANE of Nili Fossae (2009 January 19)

Posted: Fri Jan 23, 2009 3:39 am
by Frenchy
Two questions:

1. If CO2 is a repository for carbon in the inner solar system, and CH4 in the outer solar system, does this mean that they formed at different times or through different processes?

2. Does it matter where the sun is in relation to Mars in the spectrograph?

Re: all-hail ME'THANE of Nili Fossae (2009 January 19)

Posted: Fri Jan 23, 2009 4:47 am
by neufer
Frenchy wrote:1. If CO2 is a repository for carbon in the inner solar system, and CH4 in the outer solar system, does this mean that they formed at different times or through different processes?
CO2 may be a repository for carbon in the outer solar system as well
but it is too heavy a gas to be observed near the surface of a gas giant. (I'm guessing :roll: )
Frenchy wrote:2. Does it matter where the sun is in relation to Mars in the spectrograph?
The sun can't be directly behind the earth because then
there would be no Doppler shift of the Mars Methane absorption lines
needed distinguish them from Earth Methane absorption line.

One examines Methane absorption lines of frequency f
by comparing absorption differences at f±(line halfwidth)
when earth is at maximum solar elongation as seen from Mars
which can happen at during any Martian season.

When earth is moving towards Mars there will be more absorption
at f+(line halfwidth) than at f-(line halfwidth)

When earth is moving away from Mars there will be more absorption
at f-(line halfwidth) than at f+(line halfwidth)
-------------------------------------------
http://www.nasa.gov/mission_pages/mars/ ... thane.html

<<The team found methane in the atmosphere of Mars by carefully observing the planet over several Mars years (and all Martian seasons) with NASA's Infrared Telescope Facility, run by the University of Hawaii, and the W. M. Keck telescope, both at Mauna Kea, Hawaii. The team used spectrometer instruments attached to the telescopes to make the detection. The team looked for dark areas in specific places along the rainbow (light spectrum) where methane was absorbing sunlight reflected from the Martian surface. They found three such areas, called absorption lines, which together are a definitive signature of methane, according to the team. They were able to distinguish lines from Martian methane from the methane in Earth's atmosphere because the motion of the Red Planet shifted the position of the Martian lines. "We observed and mapped multiple plumes of methane on Mars, one of which released about 19,000 metric tons of methane," said Dr. Geronimo Villanueva of the Catholic University of America, Washington, D.C. Villanueva is stationed at NASA Goddard and is co-author of the paper. "The plumes were emitted during the warmer seasons -- spring and summer -- perhaps because the permafrost blocking cracks and fissures vaporized, allowing methane to seep into the Martian air. Curiously, some plumes had water vapor while others did not," said Villanueva.>>

Re: all-hail ME'THANE of Nili Fossae (2009 January 19)

Posted: Fri Jan 23, 2009 3:50 pm
by aristarchusinexile
Water vapour emitted with methane, and methane emitted by itself .. wow, Mars is an active planet beneath all that dust and rock.

Re: all-hail ME'THANE of Nili Fossae (2009 January 19)

Posted: Fri Jan 23, 2009 4:06 pm
by Chris Peterson
aristarchusinexile wrote:Water vapour emitted with methane, and methane emitted by itself .. wow, Mars is an active planet beneath all that dust and rock.
Water vapor doesn't really suggest activity, since it's very likely that a large amount of frozen water is stored close to the surface. The absence of water vapor would be the tricky question to answer. Methane is strongly suggestive of activity, since methane is less stable than water, so it is likely being manufactured by some active process. However, there are methane storage mechanisms, so the presence of this gas doesn't absolutely require activity. Stored methane (in clathrates, for example) would certainly raise all sorts of interesting questions about Mars's geologic history.

Re: all-hail ME'THANE of Nili Fossae (2009 January 19)

Posted: Fri Jan 23, 2009 4:54 pm
by aristarchusinexile
Chris Peterson wrote:
aristarchusinexile wrote:Water vapour emitted with methane, and methane emitted by itself .. wow, Mars is an active planet beneath all that dust and rock.
Water vapor doesn't really suggest activity, since it's very likely that a large amount of frozen water is stored close to the surface. The absence of water vapor would be the tricky question to answer. Methane is strongly suggestive of activity, since methane is less stable than water, so it is likely being manufactured by some active process. However, there are methane storage mechanisms, so the presence of this gas doesn't absolutely require activity. Stored methane (in clathrates, for example) would certainly raise all sorts of interesting questions about Mars's geologic history.
With the large amounts being released, and since the methane is released in summer, due to warming we can suppose, and since the surface of Mars has been 'dead' for so long, it seems to me that any simple evaporation from subsurface storage would have ended tens of millions of years ago. But it is easy to imagine organisms lying just beneath the surface, entering winter hibernation, reviving in summer, manufacturing and emiting methane. We just gotta go there, Chris .. do you think you and I could survive the trip together? Heck .. why not all of us go. I'll start building the ship but of course my funds are limited, so please send your cheques made payable to ..........

Re: all-hail ME'THANE of Nili Fossae (2009 January 19)

Posted: Fri Jan 23, 2009 10:15 pm
by neufer
Chris Peterson wrote:
aristarchusinexile wrote:Water vapour emitted with methane, and methane emitted by itself .. wow, Mars is an active planet beneath all that dust and rock.
Water vapor doesn't really suggest activity, since it's very likely that a large amount of frozen water is stored close to the surface. The absence of water vapor would be the tricky question to answer. Methane is strongly suggestive of activity, since methane is less stable than water, so it is likely being manufactured by some active process. However, there are methane storage mechanisms, so the presence of this gas doesn't absolutely require activity. Stored methane (in clathrates, for example) would certainly raise all sorts of interesting questions about Mars's geologic history.
<< Methane clathrate , also called methane hydrate or methane ice, is a solid form of water that contains a large amount of methane within its crystal structure (a clathrate hydrate). Originally thought to occur only in the outer regions of the Solar System where temperatures are low and water ice is common, significant deposits of methane clathrate have been found under sediments on the ocean floors of Earth.

Methane clathrates are common constituents of the shallow marine geosphere, and they occur both in deep sedimentary structures, and as outcrops on the ocean floor. Methane hydrates are believed to form by migration of gas from depth along geological faults, followed by precipitation, or crystallization, on contact of the rising gas stream with cold sea water. Methane clathrates are also present in deep Antarctic ice cores, and store a record of atmospheric methane concentrations, dating to 800,000 years ago. The ice-core methane clathrate record is a primary source of data for global warming research, along with oxygen and carbon dioxide.

While it is stable at a temperature of up to around 0°C, at higher pressures methane clathrates remain stable up to 18 °C. The average methane clathrate hydrate composition is 1 mole of methane for every 5.75 moles of water, though this is dependent on how many methane molecules "fit" into the various cage structures of the water lattice. The observed density is around 0.9 g/cm³. One liter of methane clathrate solid would therefore contain, on average, 168 liters of methane gas (at STP).


Image

Methane forms a structure I hydrate with two dodecahedral (20 vertices thus 20 water molecules) and six tetradecahedral (24 water molecules) water cages per unit cell. The hydration value of 20 can be determined experimentally by MAS NMR.

Methane clathrates are restricted to the shallow lithosphere (i.e. < 2000 m depth). Furthermore, necessary conditions are found only either in polar continental sedimentary rocks where surface temperatures are less than 0 °C; or in oceanic sediment at water depths greater than 300 m where the bottom water temperature is around 2 °C. In addition, deep lakes may host gas hydrates as well, e.g. the freshwater Lake Baikal, Siberia. Continental deposits have been located in Siberia and Alaska in sandstone and siltstone beds at less than 800 m depth. Oceanic deposits seem to be widespread in the continental shelf and can occur within the sediments at depth or close to the sediment-water interface. They may cap even larger deposits of gaseous methane.

The presence of clathrates at a given site can often be determined by observation of a "Bottom Simulating Reflector" (BSR), which is a seismic reflection at the sediment to clathrate stability zone interface caused by the unequal densities of normal sediments and those laced with clathrates.

The size of the oceanic methane clathrate reservoir is poorly known, and estimates of its size decreased by roughly an order of magnitude per decade since it was first recognized that clathrates could exist in the oceans during the 1960s and 70s. The highest estimates (e.g. 3×1018 m³) were based on the assumption that fully dense clathrates could litter the entire floor of the deep ocean. However, improvements in our understanding of clathrate chemistry and sedimentology have revealed that hydrates only form in a narrow range of depths (continental shelves), only at some locations in the range of depths where they could occur (10-30% of the GHSZ), and typically are found at low concentrations (0.9-1.5% by volume) at sites where they do occur. Recent estimates constrained by direct sampling suggest the global inventory lies between 1×1015 and 5×1015 m³ (1 quadrillion to 5 quadrillion). This estimate, corresponding to 500-2500 gigatonnes carbon (Gt C), is smaller than the 5000 Gt C estimated for all other fossil fuel reserves but substantially larger than the ~230 Gt C estimated for other natural gas sources. The permafrost reservoir has been estimated at about 400 Gt C in the Arctic, but no estimates have been made of possible Antarctic reservoirs. These are large amounts. For comparison the total carbon in the atmosphere is around 700 gigatons.

These modern estimates are notably smaller than the 10,000 to 11,000 Gt C (2×1016 m³) proposed by previous workers as a motivation considering clathrates as a fossil fuel resource. Lower abundances of clathrates do not rule out their economic potential, but a lower total volume and apparently low concentration at most sites does suggests that only a limited percentage of clathrates deposits may provide an economically viable resource.

Methane clathrates in continental rocks are trapped in beds of sandstone or siltstone at depths of less than 800 m. Sampling indicates they are formed from a mix of thermally and microbially derived gas from which the heavier hydrocarbons were later selectively removed. These occur in Alaska, Siberia as well as Northern Canada. In 2008, Canadian and Japanese researchers extracted a constant stream of natural gas from a test project at the Mallik gas hydrate field in the Mackenzie River delta. This was the second such drilling at Mallik: the first took place in 2002 and used heat to release methane. In the 2008 experiment, researchers were able to extract gas by lowering the pressure, without heating, requiring significantly less energy.

The sedimentary methane hydrate reservoir probably contains 2–10× the currently known reserves of conventional natural gas. This represents a potentially important future source of hydrocarbon fuel. However, in the majority of sites deposits are likely to be too dispersed for economic extraction. Other problems facing commercial exploitation are detection of viable reserves; and development of the technology for extracting methane gas from the hydrate deposits. To date, there has only been one field commercially produced where some of the gas is thought to have been from Methane clathrates, Messoyakha Gas Field.

Methane clathrates (hydrates) are also commonly formed during natural gas production operations, when liquid water is condensed in the presence of methane at high pressure. It is known that larger hydrocarbon molecules such as ethane and propane can also form hydrates, although as the molecule length increases (butanes, pentanes), they cannot fit into the water cage structure and tend to destabilise the formation of hydrates.

Once formed, hydrates can block pipeline and processing equipment.

Methane is a powerful greenhouse gas. Despite its short atmospheric half life of 7 years, methane has a global warming potential of 62 over 20 years and 21 over 100 years. The sudden release of large amounts of natural gas from methane clathrate deposits has been hypothesized as a cause of past and possibly future climate changes. Events possibly linked in this way are the Permian-Triassic extinction event, the Paleocene-Eocene Thermal Maximum. Climate scientists such as James Hansen expect that methane clathrates in the permafrost regions will be released as a result of global warming, unleashing powerful feedback forces which may cause runaway climate change that cannot be controlled. Recent research carried out in 2008 in the Siberian Arctic has shown millions of tons of methane being released with concentrations in some regions reaching up to 100 times above normal.

Since methane clathrates are stable at a higher temperature (−20 vs −162 °C) than LNG, there is some interest in converting natural gas into clathrates rather than liquifying it when transporting it by seagoing vessels. Accordingly, the production of NGH from NG at the terminal would require a smaller plant than LNG would.
------------------------

Re: all-hail ME'THANE of Nili Fossae (2009 January 19)

Posted: Fri Jan 23, 2009 11:02 pm
by bystander
Are the areas where the methane plumes were detected (Arabia Terra, Nili Fossae, Syrtis Major, et al) also areas suspected to harbor water ice? If so, clathrates seem to me to be a reasonable source. Wouldn't the radar signature of water ice be different from clathrates? This still says nothing about the original source (geo or bio). Even on Earth, clathrates are thought to originate from both.

Re: all-hail ME'THANE of Nili Fossae (2009 January 19)

Posted: Sat Jan 24, 2009 3:03 am
by neufer
bystander wrote:Are the areas where the methane plumes were detected (Arabia Terra, Nili Fossae, Syrtis Major, et al) also areas suspected to harbor water ice? If so, clathrates seem to me to be a reasonable source. Wouldn't the radar signature of water ice be different from clathrates? This still says nothing about the original source (geo or bio). Even on Earth, clathrates are thought to originate from both.
Phoenix may have come THAT CLOSE to living up to it's namesake :shock:

Image
<<Phoenix was expected to dig under the Martian soil to search for ice,
but the lander's braking rockets have already uncovered some during descent.>>
Image

Re: all-hail ME'THANE of Nili Fossae (2009 January 19)

Posted: Sat Jan 24, 2009 4:55 pm
by aristarchusinexile
bystander wrote:Are the areas where the methane plumes were detected (Arabia Terra, Nili Fossae, Syrtis Major, et al) also areas suspected to harbor water ice? If so, clathrates seem to me to be a reasonable source. Wouldn't the radar signature of water ice be different from clathrates? This still says nothing about the original source (geo or bio). Even on Earth, clathrates are thought to originate from both.
I read somewhere that the methane releases are associated with both wet and dry areas - wet signifying water sources, and whatever I read suggested the releases from the dry areas were the greater puzzle. On earth volcanism accounts for only .2% I think it was.

Re: all-hail ME'THANE of Nili Fossae (2009 January 19)

Posted: Sat Jan 24, 2009 5:04 pm
by aristarchusinexile
bystander wrote:
aristarchusinexile wrote:My other post was from Scientific American, quoted as such .. but I do agree with you that it is necessary to distinuguish possible from probable from certain.

Personally, I think the venting of methane on Mars after such a long period of surface inactivity indicates a definite certainty of methane creation below the surface at this time. If I was a gambler I would lay a large sum of money on it.
Your earlier post was not so much a quote of the article, as a paraphrase of it. (Here is a reprint of the article). In fact, your last statement (the statement Chris objected to) is found nowhere in the article.
If I direct quote from an article I use quotation marks, if I paraphrase, I'll use ' ... '. If I express my own opinion I use neither quotation marks or ' ... '. I've examined the post, and saw I included quotation marks and paraphrase marks on all but the last Methane seems to declare the verdict .. that there is life on Mars .. which comes as no surprise whatsoever. Further, the presence of methane on Titan, in far larger abundance, seems to declare life on Titan as well. Perhaps I should prefix my opinion with In my own personal opinion .. but someone not used to my formatting might think this is the opinion of the article's author instead of my own. Communication, I see, needs to be as carefully constructed as rocket science.

Re: all-hail ME'THANE of Nili Fossae (2009 January 19)

Posted: Sat Jan 24, 2009 5:08 pm
by astrolabe
Hello aristatchusinexile,

IMOPO?

Re: all-hail ME'THANE of Nili Fossae (2009 January 19)

Posted: Sat Jan 24, 2009 5:10 pm
by aristarchusinexile
astrolabe wrote:Hello aristatchusinexile,

IMOPO?
Hi Astro - what means IMOPO?

Re: all-hail ME'THANE of Nili Fossae (2009 January 19)

Posted: Sat Jan 24, 2009 5:52 pm
by bystander
aristarchusinexile wrote:what means IMOPO?
aristarchusinexile wrote:In my own personal opinion

Re: all-hail ME'THANE of Nili Fossae (2009 January 19)

Posted: Sat Jan 24, 2009 7:22 pm
by aristarchusinexile
bystander wrote:
aristarchusinexile wrote:what means IMOPO?
aristarchusinexile wrote:In my own personal opinion
Thanks Bystander and Astro .. simplicity is good.