Methane Myopia: 6 – Space Science

Methane Myopia - Space Science

Space science is the quintessential post-normal science that seeks to answer the ultimate questions of life, the universe and everything.

Space science is [also] a puzzling riddle that combines facts and heuristics with a liberal sprinkling of falsehoods, half-truths and fictions.

Unsurprisingly, space science has benefited from the scientific miasma surrounding methane gas.

The story goes back a long way.

The initial step appears to have been the banishment from Earth of Serpentinization by geologists.

Serpentinization
Methane could also be produced by a non-biological process called serpentinization involving water, carbon dioxide, and the mineral olivine, which is known to be common on Mars.

http://en.wikipedia.org/wiki/Methane#Serpentinization

The banishment of Serpentinization from Earth has been reinforced in the modern era by such luminaries as James Lovelock who stated “there is no possible inorganic process for the production of methane” in a paper published in 1969.

In the presence of this high concentration of oxygen, there is no possible inorganic process for the production of methane, either in the atmosphere or at the surface.

The rate of removal of oxygen by methane oxidation at the observed methane concentration is far greater than oxygen could be produced by photolysis in the upper atmosphere; which is the only possible abiological reaction for the production of oxygen.

Even in the highly unlikely event of the out gassing of methane at a rate sufficient to maintain its steady-state concentration against oxidation, it would still be necessary to explain the process for oxygen production.

By far, the most probable explanation, therefore, is that both oxygen and it methane are almost entirely maintained at a steady-state concentration by the Earth’s ecosystem.

Planetary Atmospheres:
Compositional and other Changes Associated with the Presence of Life.
James E. Lovelock and C. E. Giffin
Advances in the Astronautical Sciences, 25, pp.179-193, 1969.
http://www.jameslovelock.org/page19.html

Unfortunately, in the same paper, James Lovelock clearly established a connection between methane and “the presence of life”.

At the time work on this topic was commenced in 1965, it was possible to offer an experimental proof by using the chemical composition of the Earth’s atmosphere as evidence for the presence of life.

Thus, the simultaneous presence of the two gaseous components, oxygen and methane at 21 per cent and 1.5 ppm respectively, was sufficient evidence.

Planetary Atmospheres:
Compositional and other Changes Associated with the Presence of Life.
James E. Lovelock and C. E. Giffin
Advances in the Astronautical Sciences, 25, pp.179-193, 1969.
http://www.jameslovelock.org/page19.html

The next step in the methane saga was banishing the photodissociation [aka photolysis, aka photodecomposition] of methane [and water] from Earth.

Astrophysics
In astrophysics, photodissociation is one of the major processes through which molecules are broken down (but new molecules are being formed).

Because of the vacuum of the interstellar medium, molecules and free radicals can exist for a long time.

Photodissociation is the main path by which molecules are broken down.

Photodissociation rates are important in the study of the composition of interstellar clouds in which stars are formed.

Examples of photodissociation in the interstellar medium are (hv is the energy of a single photon of frequency v):
H2O + hv -> H + OH

CH4 + hv -> CH3 + H

http://en.wikipedia.org/wiki/Photodissociation#Astrophysics

It is not clear when the banishment of methane photodissociation occurred.

However, by all appearances, it was still being actively taught in 2000.

Above about 65 km, photodissociation of methane becomes the dominate mechanism for methane loss (Le Texier, et al., 1988).

NASA. Studying Earth’s Environment From Space. June 2000.
Stratospheric Ozone – An Electronic Textbook
Chapter 5: Stratospheric Photochemistry
Section 4: Catalytic Loss and Life Cycle of a Pollutant

http://www.ccpo.odu.edu/~lizsmith/SEES/ozone/class/Chap_5/5_4.htm

Similarly, it is unclear when the photodissociation of water vapour officially became an extinct species. Evidently, it wasn’t even on the endangered species list in 1950 or 1969.

Solar radiation dissociates water vapour into hydrogen atoms and hydroxyl radicles.

Hydrogen and hydrogen peroxide molecules, and perhydroxyl radicles, are also produced as a result of subsequent chemical reactions with the allotropic forms of oxygen.

The rate of the oxidizing processes falls off more rapidly with increase of altitude than does that of the reducing processes, and the hydrogen compounds are almost completely broken down at about the 90-km level (or even lower).

The photochemistry of atmospheric water vapor
David R. Bates, Marcel Nicolet – 1950 – Journal of Geophysical Research
http://www.agu.org/pubs/crossref/1950/JZ055i003p00301.shtml

The oxygen concentration would eventually stabilise at some low-level due to the equilibrium between its production by water photolysis and its removal by the processes just listed.

Planetary Atmospheres:
Compositional and other Changes Associated with the Presence of Life.
James E. Lovelock and C. E. Giffin
Advances in the Astronautical Sciences, 25, pp.179-193, 1969.
http://www.jameslovelock.org/page19.html

One of the [many] intriguing twists in this story is that by banishing the photodissociation of water [H2O] and methane [CH4] into the “interstellar medium” the mainstream has removed two sources of atmospheric hydrogen from post-normal Atmospheric Chemistry.

Unsurprisingly, this presents a golden opportunity for invention, obscuration and scare stories.

Unsurprisingly, the mainstream never lets a good money making opportunity go to waste.

For instance:

By banishing the photodissociation of water vapour [H2O] the mainstream [in one bound] removed the connection between atmospheric water vapour and the oxygen-ozone cycle.

The post-normal Oxygen-Ozone Cycle

Ozone-oxygen cycle in the ozone layer:
1. Oxygen photolyzed to atomic oxygen
2. Oxygen and ozone continuously interconverted.
Solar UV breaks down ozone; molecular and atomic oxygen combine.
3. Ozone is lost by reaction with atomic oxygen (plus other trace atoms).

http://en.wikipedia.org/wiki/Ozone-oxygen_cycle

Thus, in another giant step for mankind, the mainstream created the Ozone Hole Scare by removing the connection between the level of atmospheric water vapour and the level of atmospheric ozone.

Ozone Depletion

http://en.wikipedia.org/wiki/Ozone_depletion

By banishing the photodissociation of water vapour [H2O] the mainstream [in another fit of creative genius] managed to create an endlessly looping Water Cycle.

The Water Cycle

The Water Cycle has no beginning.
The Water just is [presumably created by the almighty Big Bang].
The Water Cycle has no end.
The Water Cycle just goes on forever and ever, amen.
The Water Cycle is framed with a genuine antique border just to prove its authenticity.

The endlessly looping cycle is a favoured motif in post-normal science because everyone can now happily go round and round in circles without ever progressing.

This brand of post-normal science is affectionately know as Play School Science because the scientists chose the round window before telling their story.

Play School

http://www.thechestnut.com/play.htm

Every day on Play School there was just one question demanding to be answered.
Which Window would it be?

http://www.bbc.co.uk/cult/classic/playschool/game.shtml

Sadly, the fate of the hydrogen liberated by the photodissociation of methane [and water] has been equally tragic even though the post-normal scientists now have only a tiny whiff of hydrogen to play with in the lower atmosphere [0.55 ppmv or 0.000055%].

Needless to say, the hydrogen boffins chose the round window.

Hydrogen cycle
Anaerobic fermentation of organic substances to carbon dioxide and methane is a collaborative effort involving many different biochemical reactions, processes and species of microorganisms.

http://en.wikipedia.org/wiki/Hydrogen_cycle

Unfortunately, the hydrogen cycle just seems to fizzle out at that point and they have to waffle about “interspecies hydrogen transfer” until they can move onto [surprise, surprise] Global Climate.

Now, in a tragic twist of fate, hydrogen [liberated by the banished photodissociation of methane and water] is accused of being a “secondary greenhouse gas” and of “interfering with the removal of methane from the atmosphere” because it “interacts with hydroxyl radicals” [OH].

H2 is a trace, secondary greenhouse gas that interferes with the removal of methane.

http://en.wikipedia.org/wiki/Hydrogen_cycle

[sarcasm on]
This is evidently a really, really serious problem because the puff of methane [1.79 ppmv] in the atmosphere outnumbers the whiff of hydrogen [0.55 ppmv] by a factor of 3.25.
[sarcasm off].

This is also really strange because my post-normal atmospheric chemistry textbook states that “roughly” 70% of OH reacts with CO to produce [strangely enough] CO2 and H while the remaining 30% of the OH reacts with methane [CH4] to produce CH3 and H2O [water].

Sadly, nobody seems to be able to agree upon the parentage of Hydrogen.

Some suggest it is produced by “bacteria and algae” and then farted into existence.

Hydrogen gas is produced by some bacteria and algae and is a natural component of flatus, as is methane, itself a hydrogen source of increasing importance.

https://en.wikipedia.org/wiki/Hydrogen#Natural_occurrence

Others suggest it is produced by serpentinization [but don’t worry because it only happens] “in deep geological conditions prevailing far away from Earth atmosphere”.

In the absence of atmospheric oxygen (O2), in deep geological conditions prevailing far away from Earth atmosphere, hydrogen (H2) is produced during the process of serpentinization by the anaerobic oxidation by the water protons (H+) of the ferrous (Fe2+) silicate present in the crystal lattice of the fayalite (Fe2SiO4, the olivine iron-endmember).

https://en.wikipedia.org/wiki/Hydrogen#Geological_occurrence:_the_serpentinization_reaction

Unsurprisingly, after all this abuse, hydrogen is very keen to leave the building.

But [again] don’t worry.

Hydrogen gas is “very rare” in the atmosphere [so it only escapes rarely] and [anyway] we’ve got plenty of it to spare [so there] because it’s “the third most abundant element on the Earth’s surface”.

However, hydrogen gas is very rare in the Earth’s atmosphere (1 ppm by volume) because of its light weight, which enables it to escape from Earth’s gravity more easily than heavier gases.

However, hydrogen is the third most abundant element on the Earth’s surface, mostly in the form of chemical compounds such as hydrocarbons and water.

https://en.wikipedia.org/wiki/Hydrogen#Natural_occurrence

To reinforce these reassuring words the settled scientists have theoretically calculated that the Earth is losing a measly 3 kilograms of hydrogen and 50 grams of helium every second.

Earth is too large to lose a significant proportion of its atmosphere through Jeans escape.

The current rate of loss is about three kilograms (3 kg) of hydrogen and 50 grams (50 g) of helium per second.

https://en.wikipedia.org/wiki/Atmospheric_escape

Hydrogen and Helium Escape

So we don’t need to worry about where all the hydrogen came from that’s locked upon in methane and water or is happily making its way up into the upper atmosphere.

The upper part of the heterosphere is composed almost completely of hydrogen, the lightest element.

http://en.wikipedia.org/wiki/Earth%27s_atmosphere#Other_layers.

So we don’t need to worry about where the hydrogen in the exosphere is going even if it’s already “half way to the Moon”.

The exosphere is the outermost layer of Earth’s atmosphere, ranging from the exobase at an altitude of about 700 km. above sea level to about half way to the Moon.

It is mainly composed of hydrogen, helium and some heavier molecules such as nitrogen, oxygen and carbon dioxide closer to the exobase.

http://en.wikipedia.org/wiki/Earth%27s_atmosphere#Exosphere

Instead, we are urged to get excited about finding other life forms in the Solar System.

Now, this is where all the post-normal atmospheric chemistry starts to fall [very neatly] into place.

Luckily, the post-normal settled science boffins in atmospheric chemistry have established what the Earth’s atmosphere would look like if there was NO life on Earth.

Thus, through the magic of science and comparison, they can determine the profile of atmospheric gases that specifically indicate the presence of Life on Earth.

Any guesses?

Life's Influence on Earth's Atmosphere

Examination of this wondrous chart reveals the unique, unequivocal Life on Earth atmospheric markers are hydrogen [at 0.55 ppmv] and methane [at 1.79 ppmv].

Now this isn’t really very useful [or very truthful – but that’s another story].

Firstly, hydrogen is the most abundant element in the Universe.

Hydrogen is a chemical element with chemical symbol H and atomic number 1.

With an atomic weight of 1.00794 u, hydrogen is the lightest element and its monatomic form (H) is the most abundant chemical substance, constituting roughly 75% of the Universe’s baryonic mass.

http://en.wikipedia.org/wiki/Hydrogen

Secondly, methane has been found at [just about] every interesting location in the solar system.

Mercury, Venus, Earth, Moon, Mars, Saturn [and Iapetus, Titan, Enceladus], Uranus [and Ariel, Miranda, ,Oberon, Titania, Umbriel], Neptune [ and Triton], Pluto [and Charon], Eris, Comet Halley, Comet Hyakutake.

http://en.wikipedia.org/wiki/Methane

Note: This Wikipedia list [curiously] excludes Jupiter’s methane and ignores its moons.

What is also remarkably strange is that the Moon [and all those other lumps of rock where “life” does not exist] can outgas methane while the Earth can only produce methane [and hydrogen] biologically.

Moon – traces are outgassed from the surface

http://en.wikipedia.org/wiki/Methane#Extraterrestrial_methane

However, this is all remarkably useful for the “Space Rangers” because they can now waltz around the solar system searching for life provided there is some puff of methane or whiff of hydrogen floating around somewhere in the vicinity i.e. everywhere.

Unfortunately, searching for life doesn’t mean intelligent life.

The search for extraterrestrial intelligence (SETI) is the collective name for a number of activities undertaken to search for intelligent extraterrestrial life.

In 1995, the United States federal government ceased funding to SETI projects, forcing them to turn to private funding to continue the search, though in recent years government funding of SETI has resumed at modest levels.

http://en.wikipedia.org/wiki/Seti

Regrettably, this anal fixation with methane means our search for life is targeting our old friends the [oxygen phobic] methanogens.

Methanopyrus kandleri

Methanopyrus kandleri
http://en.wikipedia.org/wiki/Methanogen

Another strange aspect of all this speculative planetary probing [and roving] by the “Space Rangers” is that it is all spectacularly unnecessary because mass spectrometry can be used to determine whether the methane gas is of biogenic or abiogenic origin.

James Lovelock, back in 1969, provides a clue when he concluded, after assessing the “evidence”, that Mars “may not be far from an abiological steady-state”.

In 1965, we were interested to know the extent to which information on the chemical composition of planetary atmospheres could constitute direct and primary evidence of life.

In other words, could the chemical analysis of a planetary atmosphere constitute a life detection experiment?

We convinced ourselves and a few others that such an experiment could indeed detect the presence of life on a planet with a signal to noise ratio at least as good as that of other life detection experiments.

At that time, the detection of life on Mars seemed ample justification for this exobiological exercise; as time passed, however, evidence accumulated from the Mariner missions and from the Infrared astronomy of the Connes and Kaplan to suggest that Mars may not be far from an abiological steady-state and therefore unlikely to be a base for life.

At this time, therefore, especially in view of the restricted funds available for planetary exploration, it seems relevant to ask: is there sufficient justification for a biologically oriented atmospheric analysis experiment?

Planetary Atmospheres:
Compositional and other Changes Associated with the Presence of Life.
James E. Lovelock and C. E. Giffin
Advances in the Astronautical Sciences, 25, pp.179-193, 1969.
http://www.jameslovelock.org/page19.html

Then, after a 37 year long pause, a paper by P. Buford Price [on the topic of Methanogens on Mars] provides further details about the mass spectrometry technique for distinguishing a biogenic gas from an abiogenic gas.

The usual way to distinguish whether a gas such as CO2 or CH4 is biogenic or abiogenic is to measure the ratio of two stable isotopes in the gas.

A mass spectrometer able to measure the composition of the stable carbon isotopes in martian methane with high sensitivity could determine whether it is biogenic or abiogenic.

Biogenic and Abiogenic Methane

Figure 7 shows the range of values of d13C in various methane sources, using the conventional definition for d13C as the permil deviation of the isotopic ratio of a sample relative to the PDB carbonate standard that defines zero permil on the d scale:

Reading down, one sees that methane in carbonate rocks, in the mantle and in carbonaceous chondrites is abiogenic, and methane emitted by cattle, by termites, in sedimentary organics, in the Earth’s atmosphere, from plants (recently discovered), in natural gas, in rice paddies, in peat deposits, from methanogens, in sea-floor methane hydrates and in Greenland silty ice (Souchez, Jouzel & Landais et al., manuscript in preperation) is biogenic.

Methane on the moon was found by MS of lunar soil to be abiogenic (Chang et al.,
1974), and methane in the lower atmosphere of Titan was found by the Gas Chromatograph/Mass Spectrometer (GC/MS) on the orbiting Huygens probe to be abiogenic (Niemann et al., 2005).

Detection of a value of d13C more negative than about -50% would be strong evidence for the presence of living methanogens on Mars.

Microbial life in glacial ice and implications for a cold origin of life
P. Buford Price – Physics Department, University of California, Berkeley, USA
http://onlinelibrary.wiley.com/doi/10.1111/j.1574-6941.2006.00234.x/pdf

The chart clear shows the biogenic range for Methanogens [on Earth] never exceeds -45%.

Therefore, coupled with the knowledge that only Methanogens produce biogenic methane on Earth, it seems highly likely the following methane “sources” on Earth contain some abiogenic methane:
a) Cows and Termites
b) Sedimentary Organics
c) Atmosphere
d) Natural Gas
e) Rice Paddies
Biogenic and Abiogenic Methane - Annotated
Finally, it seems highly unlikely that the “Space Cadets” would embark upon a roving mission to Mars before they had performed this basic analysis, especially as they appear to have publicly determined the atmosphere of Titan is abiogenic [at least until they change their minds].

Where the truth lies is hard to determine.

However, what is clear is that when it comes to space science the show must go on.


To be continued…

Footnote

The carefully devised life absent / life present diagram appears in [at least] two mainstream textbook on atmospheric chemistry [but without the text showing “ppmv”].

There is also a slightly dodgy version of the diagram at:
http://www.es.flinders.edu.au/~mattom/IntroOc/notes/figures/intro1fig1.html

The logarithmic scale manages to visually diminish the atmospheric dominance of nitrogen and oxygen while visually overstating the presence of trace gases, such as, methane and hydrogen.

This is [undoubtedly] an accidental optical illusion given the impeccable credentials of Professor Peter Liss [who apparently devised the diagram].

Climate change sceptics ‘playing Russian roulette with planet’

Prof Peter Liss, acting director of the University of East Anglia’s Climatic Research Unit (CRU), said sceptics were endangering the lives of generations to come by making unsupported claims.

Daily Telegraph – 12 Feb 2010
http://www.telegraph.co.uk/earth/environment/climatechange/7221110/Climate-change-sceptics-playing-Russian-roulette-with-planet.html

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3 Responses to Methane Myopia: 6 – Space Science

  1. oldbrew says:

    This might be of interest.

    ‘Experiments have shown that under extreme conditions of heat and pressure it is possible to convert iron oxide, calcium carbonate and water into methane, with hydrocarbons containing up to 10 carbon atoms being produced by Russian scientists last century and confirmed in recent US experiments.’
    http://viewzone.com/abioticoilx.html

    The question of how the methane lakes and methane-filled atmosphere on Titan came to be there is also ‘interesting’, given the presumed lack of vegetation, fossils etc.

    REPLY
    Thanks for the information…
    Titan is very interesting… watch this space 🙂

  2. Brian H says:

    All water molecules in the outer atmosphere would surely be photodissociated, with consequent loss of hyrdrogen to the exosphere. How is it replenished? We should have no more water than Venus by now.

    • malagabay says:

      How is it replenished?

      That’s a key question.
      There seems to be only two possible answers:
      1) From outer space.
      2) From within the Earth.

      The mainstream have gone with option one and invented “dirty snowball” comets and extraterrestrial water raining down on Earth. Then they mathematically limit hydrogen escape to just 3kg a second [just to be safe].

      However, I don’t think the Apollo missions or the International Space Station have wiper blades on their windows and “space weather” forecasts never predict rain, hail, snow or fog.

      So that leaves option two.

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