Methane on Mars - Proof for life on Mars?

C M Edwards · 2004-04-01 10:33:35

I don't know if they are fossils or not.

As for the methane, at what rate should it be breaking down? A constant rate, or does it have a half-life? That would help determine either a) The rate of replenishment or b) How high the levels must have been in the past to have diminished to their present level.

SBird · 2004-04-01 13:09:21

John - I finished your paper - good work on that, BTW. In there, you mention the likelihood that subsurface radar can't easily distinguish ice from the regolith. Is that still true for that ice-imaging radar on the MRO going up in 2005?

Also, have you had access to the CH4 measurement data yet? I'm curious how the concentration profiles they found with Mars Express match up to your simulation data and what that implies about the source size and rate.

Bill White · 2004-04-01 15:49:24

This e-mail has been sent to folks on the Mars Society mailing list:

Methane Detection Points to Life on Mars
Robert Zubrin
March 31, 2004
For further information about the Mars Society, visit our website at [http://www.marssociety.org]www.marssociety.org.
Over the past week a series of discoveries have been announced that radically enhance the prospects for the search for life on Mars.
The first announcements came for the MER science team led by Cornell University geologist Steven Squyres which identified the Meridani Planum landing site of the Opportunity rover as the shoreline of an ancient salty sea. "If you want to look for fossils, this is the place to go," NASA Associate Administrator for Space Science Ed Weiler commented.
As exciting as the MER results were, however, they were superceded two days later by the results of the team of V. A. Krasnopolsky, J. P. Mailard, and T.C. Owen, who published a paper announcing that, using the Canada-France-Hawaii telescope, they had detected methane in the Martian atmosphere at a level of about 11 ppb. As small as
this concentration is, it is anomalous, and cannot be explained by abiotic processes. We quote directly from the Krasnopolsky team's abstract, entitled "Detection of Methane in the Martian Atmosphere: Evidence for Life."
"…we detected the absorption by Martian methane at a 3.9 sigma level. The observed CH4 mixing ratio is 11 +-4 ppb. Total photochemical loss of CH4 in the Martian atmosphere is equal to 180,000/cm2-s, and the CH4 lifetime is 440 years. Heterogeneous loss of atmospheric methane is probably neglible, while the sink of CH4 during its diffusion
through the regolith may be significant. There are no processes of CH4 formation in the atmosphere, so the photochemical loss must therefore be balanced by abiogenic and biogenic sources. The mantle outgassing of CH4 is 4000/cm2-s on the Earth, and smaller by an order
of magnitude on Mars [i.e. much smaller than the required 180,000/cm2-s to make up the loss rate- RZ] The calculated production of CH4 by cometary impacts is 2.3 percent of the methane loss. Methane cannot originate from an extinct biosphere, as in the case of "natural gas' on Earth, given the exceeding low limits on organic matter set by the Viking landers and the dry recent history which has been extremely
hostile to the macroscopic life needed to generate the gas.
Therefore, methanogenesis by living subterranean organisms is the most likely explanation for this discovery. Our estimates of the biomass and its production using the measured CH4 abundance show that the Martian biota may be extremely scarce and that Mars may be generally sterile except for some oases."
One day after the publication of the Krasnopolsky group abstract, two more teams let it be known that they had measured similar results. One of the teams, led by Mike Mumma of NASA Goddard Spaceflight Center, used NASA's Infrared Telescope Facility in Hawaii and the international Gemini South observatory in Chile to make its measurements. The other team, led by Professor Vittorio Formisano,
head of research of the Italian National Council for Research's
Institute of Physics and Interplanetary Space, used the Planetary Fourier Spectrometer instrument on the ESA Mars Express spacecraft. Both the Formisano group and the Mumma group reported methane measurements in the 10 to 10.5 ppb range, in excellent agreement with each other and the 11 ppb results reported by the Krasnopolsky team.
So we now have three teams, using four different instruments, all reporting nearly identical methane measurements. The evidence for validity of the measurements must therefore be taken as very strong, and the key questions are those relating to interpretation, significance, and necessary follow-up.
Interpretation For reasons explained in the Krasnopolsky abstract quoted above, the most likely interpretation is that the methane is a product of the metabolism of indigenous microbes. Methanogenic bacteria are common on Earth, and include members of the most archaic subgroup of
bacterial life. The MER results show conclusively that surface
environments that could have hosted rich microbial ecologies once existed on Mars, and geologically recent runoff channels imaged by Mars Global Surveyor (MGS) strongly indicate that subsurface reservoirs that could host microbes probably exist on Mars today.
The alternative explanation, that the methane is a product of
geothermal activity, appears unlikely in view of the TES and THEMIS measurement taken by NASA's MGS and Mars Odyssey orbiters. Either of these spacecraft should have been able to detect the thermal emissions associated with such activity, but they have not. This makes the geothermal explanation for the origin of the Martian methane almost untenable. Furthermore, if somehow such hydrothermal
environments did exist regardless, then they themselves would provide wonderful candidate environments for a host of microbial life forms.
So, while not constituting definitive proof, the preponderance of the evidence strongly points to life.
Significance
The significance of the detection of life on Mars is enormous. There are two possibilities:
1. The life detected on Mars has a common origin with Earth life.
2. The life detected on Mars has a separate origin from Earth life.
Within the common origin possibility (1), there are three
alternatives:
a. Mars life is descended from Earth life
b. Earth life is descended from Mars life
c. Both Earth life and Mars life are descended from a third
source.
While alternative (a) is possible in principle, it is the least
likely of the three, since natural material transfer from Mars to
Earth (via meteoritic impact) is easier than from Earth to Mars, and since Mars cooled quicker than the Earth (both planets were originally molten), life would have had an opportunity to originate on Mars first. Furthermore, one to the great mysteries about life on Earth is that we find no free-living organisms on Earth simpler than bacteria, which are actually highly complex – much too complex to represent the first life forms to emerge from chemistry. This anomaly
has led numerous investigators since the 19th Century to suggest that life may not have originated on Earth at all, but represent an immigrant phenomenon. This leaves us with (b) or ©
If (b) is true, and Mars is the homeland of life, then by going to Mars we have the possibility of discovering free-living life forms more primitive than bacteria, and who therefore present a living record of the missing links between chemistry and life. By examining them, we could read the book of life itself, and finally gain an understanding of the process that allowed for the creation of all living things.
If © is true, we would find no free-living organisms on Mars
simpler than archaic bacteria of similar plan to those observed on Earth. In that case, we would have proof that the planets of our solar system were seeded early in their history by bacterial spores transported across interstellar space. This would be proof of the theory of panspermia, and its inevitable consequence that life is present on billions of planets across our galaxy.
Alternatively, if (1) is false, then (2) must be true, in which case what we have on Mars is a second genesis. If this is the case, it would also imply that life is a general phenomenon in the universe, since we would have proof through success stories in two out of two cases that life tends to develop from non-life wherever it has an acceptable physical environment. Furthermore, however, the existence
of such a second genesis would provide us with an opportunity to determine whether the biochemical plan of life that is common to all Earth life-forms is the pattern for all life everywhere, or whether we are just one peculiar example of a much vaster and more diverse tapestry of life that pervades the cosmos.
In other words, the detection of life on Mars is an invitation to an investigation whose results could provide us answers to the most profound questions humans have ever asked concerning the origin and fundamental nature of life.
Follow-up
The key issue therefore, is not whether there is life on Mars, but WHAT is the life on Mars. To answer that question, drilling rigs will need to be set up on the Martian surface capable of penetrating down to the locations of the subsurface liquid reservoirs which host the Martian microbes, and water samples extracted. The water samples will then need to be cultured to see if they contain microbes, and if they do, then the microbes need to be imaged through a variety of techniques and subjected to a battery of biochemical tests. This sort of investigation can be carried out only by human explorers operating on the surface of Mars.
NASA's new Space Exploration Initiative has just been handed its mission assignment.
An in-depth discussion of the significance of the methane detection discovery for the search for life on Mars will be held at the 7th International Mars Society Convention, Palmer House Hilton, Chicago IL, Aug 19-22, 2004. Registration is now open at [http://www.marssociety.org]www.marssociety.org.
For further information about the Mars Society, visit our website at [http://www.marssociety.org]www.marssociety.org.

lunarmark · 2004-04-02 06:59:26

How exactly did they determine what the lifetime of methane in the martian atmosphere is (I heard about 300 years), presumably it is a photonic decomposition due to sunlight situation. Do we know enough about the chemistry of the atomosphere to be sure?

SBird · 2004-04-02 11:07:56

Mr. McGowan can probably answer that question much more accurately than I. However, I'm going to guess that the estimates are laregly computational. Basically, they know the overall atmospheric composition of Mars and the solar radiation flux levels. The interactions of CH4 with UV are known and from there, it's a simple matter of doing some mass-balance calculations to get a half life.

The primary complicating matter would be the soil. CH4 effective half life will go up if there's soil types that can temporarily bind it and go down if there are siol type that catalyze the CH4 breakdown reaction.

Overall, I'd say it's safe to assume that the calculated halflie is correct to within a factor of 2 of the stated figure. IT's not going to a be a million years or something.

Zubrin's statement above is interesting. I was unaware of the THEMIS readings. They would seem to indicate that there is a biological component to this phenomemon. However, as is not uncommon, Zubrin seems to be overstating the matter a bit. I'd still guess that geological souces are a major factor here. However, as the primary methane sources are geothermal activity, active life and hydrocarbon deposits, the methane stil points toward a much higher probability of active Martian life.

Bill White · 2004-04-02 11:32:17

Mr. McGowan can probably answer that question much more accurately than I. However, I'm going to guess that the estimates are laregly computational. Basically, they know the overall atmospheric composition of Mars and the solar radiation flux levels. The interactions of CH4 with UV are known and from there, it's a simple matter of doing some mass-balance calculations to get a half life.
The primary complicating matter would be the soil. CH4 effective half life will go up if there's soil types that can temporarily bind it and go down if there are siol type that catalyze the CH4 breakdown reaction.
Overall, I'd say it's safe to assume that the calculated halflie is correct to within a factor of 2 of the stated figure. IT's not going to a be a million years or something.

Zubrin's statement above is interesting. I was unaware of the THEMIS readings. They would seem to indicate that there is a biological component to this phenomemon. However, as is not uncommon, Zubrin seems to be overstating the matter a bit. I'd still guess that geological souces are a major factor here. However, as the primary methane sources are geothermal activity, active life and hydrocarbon deposits, the methane stil points toward a much higher probability of active Martian life.

Zubrin overstate? Really?

SBird · 2004-04-02 13:36:09

I was trying to be nice.

lunarmark · 2004-04-05 08:40:31

Thanks for that.

what about one other source of methane?, I wonder if methane could be produced from a the impact of a carbonaceous meteorite(s) i.e a comet a impact? since they contain 5% typ carbon as well as a large amount of voitile organic/aromatics and water.

if you had a large comet(s) that vaporised in the upper atmosphere, you would liberate a large amount of carbon based molecules maybe the methane can be expalined in this way?

Just a thought.

SBird · 2004-04-05 10:48:42

CH4 won't be formed in the impact. It's a high energy molecule and won't survive at the temperatures created in an impact. However, if carbon and hydrogen are present in a geological underground deposit, they can form hydrocarbons and then CH4 of very long periods of time. Whether this is a process that actually occurs, I don't know. It's difficult to imagine that this process could account for the quantities of CH4 being observed, though.

Shaun Barrett · 2004-04-06 05:28:15

As someone else has recently pointed out, there was a report last year that one or two 'hotspots' had been detected in Hellas Basin by one of the orbiters - Odyssey, I believe(?).
Admittedly, we've heard little or nothing about them since but why have they not featured as a possible explanation for the methane? Is it that they are too small to account for the quantity of CH4 observed or have they been found to be no more than a thermal glitch in the data, no longer visible on subsequent passes over the area in question?

My feelings about the methane are rather mixed. While there is almost no doubt in my mind that Mars possesses a biosphere, I tend to think it would be extremely frugal with organic material. It should be holding on to that methane and finding some way to utilise it before it escapes into the atmosphere. Perhaps it's a case of there being a large biosphere in the crust and this methane we're seeing is just what's left after the organisms concerned have recycled 90-something percent of it! These wisps of CH4 are just the 'scraps' of a very 'tight' community which, despite its best efforts, can't quite manage to save all of the organic material available to it.
Just a thought.

Palomar · 2004-04-06 06:00:14

*I scrolled through the posts before pasting and copying the text below, which I read in an article pertaining initially to Titan (and posted in the "Huygens Probe to Titan" thread by me a few days ago). The relation to Mars is in the 3rd paragraph:

"Although Titan's underlying surface is thought to be water ice, the complex chemistry in the upper atmosphere might have resulted in the icy surface being at least partly covered in liquid ethane and methane and solid hydrocarbons. One class of the solid hydrocarbons, often referred to as Titan tholins (from the Greek word, muddy), was artificially created in a laboratory by a team led by the late Cornell astronomer Carl Sagan.

When scientists analyze the building blocks of tholins by burning them (pyrolysis), splitting up the tholins using plasma, scientists find a rich array of biomolecular building blocks such as pyrroles, pyrazines, pyridines and pyrimidines.

All of these molecules have played an important role in the evolution of terrestrial life. Recent reports of methane on Mars have sparked interest in their volcanic or biological origins, --->because in the thinner martian atmosphere, ultraviolet radiation quickly destroys methane without an underlying source to replenish it.<----"

*Not a "strong suit" subject (chemistry and gases) for me, but I thought I'd post it.

[http://www.spacedaily.com/news/saturn-titan-04e.html]Article

--Cindy

Shaun Barrett · 2004-04-07 02:05:26

All very interesting stuff - thanks, Cindy!

Bill White · 2004-04-28 20:46:39

Shaun has posted that he thinks there is life on Mars today. He will like this link:

The bacteria and archaea that live in these strange methane-rich environments are utterly fascinating and still very mysterious. The most intriguing of all are the anaerobic methane-oxidising guys. Most microbes that eat methane do so with the help of oxygen. The anaerobic ones make use of sulphates instead. If you're looking at all this from a martian point of view, that's a potentially rather interesting trick, because Mars has very little oxygen, but as Opportunity has been demonstrating it has a great deal of sulphate to offer. If there are bugs on Mars making methane, then there might well be others turning it into carbon dioxide with the help of sulphates If that's the case the methane that makes it to the atmosphere would be only a fraction of the methane actualy produced, and the martian biosystem might be a fair bit bigger than it would appear at first blush.

http://mainlymartian.blogs.com/semijour … ..._5.html

Shaun Barrett · 2004-04-29 06:09:38

Many thanks, Bill!
It was nice of you to remember my views on potential martian life when you spotted this blog. The methane recently confirmed in the martian air certainly does add some weight to the idea that Mars has a bacterial biosphere and it's always gratifying to see one's pet hypotheses gather strength.
I suppose there's still quite a way to go, though, before definitive proof of life on Mars is declared. The whole planet could be as sterile as motel decor for all the absolute proof I have!

But I doubt it.

SpaceNut · 2004-11-12 11:31:19

Well the methane find is in the news again but this time not reported from an orbiting probe but from Earth based telescopes though spectral signature of methane (CH4) in the Martian atmosphere.

Mars Methane Boosts Chances for Life

Using NASA's 3-meter Infrared Telescope Facility atop Mauna Kea, Hawaii, Mumma and his colleagues detected methane at a level of 250 parts per billion in equatorial latitudes north of the Hellas impact basin.

SpaceNut · 2018-04-28 21:14:30

Bump old topic artifacts removed and is now repaired

SpaceNut · 2019-06-22 20:31:39

Its been hint at before that Curiosity rover finds gas levels on Mars hinting at possibility of life

Of course the suggestion of life is what we are looking for with the methane.

SpaceNut · 2019-06-23 20:34:04

Life on Mars gets a test run in the Utah desert

looks alot like mars....

SpaceNut · 2019-08-25 19:13:06

http://www.marsdaily.com/reports/A_step … s_999.html

Is mars dead or is there hidden life.

The methane puffing from a huge crater on Mars could be a sign of life or other non-biological activity under the planet's surface. Gale crater, which is 154 km in diameter and about 3.8 billion years old, is thought by some to contain an ancient lakebed.

https://doi.org/10.1029/2019GL083800

louis · 2019-08-26 15:09:06

Sounds like a v. small amount of methane (2.5kg per sol) for such a large area, if life were current and ubiquitous. But...who knows? We need to get there to find out.

SpaceNut wrote:

http://www.marsdaily.com/reports/A_step … s_999.html
http://www.spxdaily.com/images-hg/mars- … ter-hg.jpg
Is mars dead or is there hidden life.
The methane puffing from a huge crater on Mars could be a sign of life or other non-biological activity under the planet's surface. Gale crater, which is 154 km in diameter and about 3.8 billion years old, is thought by some to contain an ancient lakebed.
https://doi.org/10.1029/2019GL083800

SpaceNut · 2019-08-26 18:46:25

The mass is a gaseous measurement so the story of it spread out over an area would be very low pressure which is where I think mars real atmosphere points. Even the moxie unit is measuring a days activity in grams.

MOXIE is designed so that it will operate for 50 Martian days (about 51 Earth days) and will produce about 20 grams (0.7 ounces) of oxygen per hour.
Hoffman and Hecht hope to send a larger version of MOXIE to Mars some time in the 2030s that would produce about 2 kilograms of oxygen per hour.

http://www.niac.usra.edu/files/library/ … ngland.pdf

0.8 kPa compressed until you have a volume of liquid co2 that happens when we get to 400 kPa which will contain just 3% oxygen
...

Oldfart1939 · 2019-08-31 16:25:17

Methane presence is a necessity of our form of life, but is at best, inconclusive. I am not convinced, and we need a human laboratory presence for corroborating evidence by finding other bioorganic molecules present in soil and water.

SpaceNut · 2019-08-31 18:09:31

https://www.space.com/31414-mars-methan … signs.html
2015 getting closer to saying it just might be life...

Mars has perchlorates which make it unique for biological signs. Biological methane production under putative Enceladus-like conditions

With chloride I would think there would be some other signs mixed in for life.

Perchlorate bio-reduction in a methane-based membrane biofilm reactor in the presence and absence of oxygen.

elderflower · 2019-09-09 08:04:44

It may of course be that methane occurs in the atmosphere in Gale crater because that is where there is a rover scuffing the soil and releasing small amounts of adsorbed gases.

SpaceNut · 2019-09-22 09:54:01

A good question for the analog site is there any methane detectable for seeing if we are near mars conditions.
I see plant life in some of the sites images so I would think that there would be...

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