Methane on Mars - Proof for life on Mars?

SBird · 2004-03-28 15:05:05

Fresh off the press, two independent teams have reported finding low levels of methane in the Martian atmosphere. One was using ground-based telescopes and the other used Mars Express data. Although geological sources haven't been ruled out, this is a strong sign of an active Martian ecosystem.

C M Edwards · 2004-03-28 19:49:56

Methane is only a sign of life if it is present in sufficient concentration that it would be out of chemical equilibrium without a source.

Is the methane in Mars' atmosphere really at that high a concentration if it hasn't been detected by now?

Cairan · 2004-03-28 21:26:35

Non-replenished CH4 gets eliminated in about 300 years in the Martian atmosphere, due to photochemistry with the Sun's UV. There needs to be a replenishment. What that source is, that's the 800 million dollar question.

SBird · 2004-03-28 22:23:45

That's correct, the CH4 is definately out of chemical equilibrium. The question, as Cairan puts it is what the source is. Apparently (I've never heard this, but then, there's lots I don't know) the presence of CH4 in the Martian atmosphere has been something of a holy grail of Mars researchers looking for life.

However, this assumes that there is no residual geological activity on Mars. Geological activity (read: volcanic activity)and certain water-rock interactions can create CH4. Either that, or the Martians got a hold of a Case for Mars and started up a Sabatier reactor to make fuel for their invasion of earth.

Mark Friedenbach · 2004-03-29 06:09:51

http://news.independent.co.uk/world/sci … ory=505454

Is the methane in Mars' atmosphere really at that high a concentration if it hasn't been detected by now?

10 to 10.5 parts per billion. That's a very low concentation in a very thin atmosphere. And like Cairan said, there shouldn't be any methane in the martian atmosphere.

lunarmark · 2004-03-29 06:10:42

It is worth sounding a note of caution here, there could easilly be a chemical answer for the methane, Mars has a highly oxidising/reducing soil, for example the methane might be trapped deep at the pole from past volcanic activity and released during melting... or there may be some residual thermal activity still going on, - even our moon, may still have a warm core, which could allow accasional outgassing, (though this is controversial).

Thermal cooling of planetary bodies is poorley understood, it is entirley possible that the Methane is volacnic in origin and mars's interior is warmer than thought.

Julius Caeser · 2004-03-29 10:40:47

I'll have to agree with lunarmark regarding the possibilities existing for the origin of methane.Prior to the finding of methane on Mars,scientists were not excluding that the planet might still be geologically active.Orbital pics of lava flows on Mars seem to corroborate this since some flows are free of craters indicating a young age...i believe the ones indicated to demonstrate this were the elysium flows.The argument for failing to see any present activity on the surface is that the last eruptions may have occurred few millions to thousands of years ago and hence some volcanoes may just be dormant rather then extinct,Its a matter of time until the next volcano comes to life!The finding of methane could push that latest geological activity to more recent history thou..to hundreds of years..still Mars as agreed is geologically dead when compared to say Earth or Venus.

SBird · 2004-03-29 11:29:36

The hopeful thing here, though is that this is a win/win situation. If the CH4 is from life - huzzah! If the CH4 is from geological activity - huzzah!

Geological activity would indicate that there are active hot springs which greatly increase the probability of life. Not to mention the availability of liquid water and geothermal power.

One thing to keep in mind is that 10 ppb of CH4 represents about 260 million kg of CH4. Whatever is making this CH4 is doing so in substantial quantities. It's also apparently geographically localized - again hinting at either a geologically active region or a life-rich region. And, of course, there's also the possibility of both - CH4 emitting volcanic vents with methanogens living in them.

Julius Caeser · 2004-03-29 11:56:15

SBird, Episodic geological activity on Mars has already been manifested by the fresh looking gullies we see in a few craters in mid southern latitudes ( that could also explain the distribution of methane along equatorial regions!)Strangely enough,methane has never been discussed in relation to these martian phenomena.Now whether volcanic activity on a larger scale is occurring is still to be seen.I guess this finding opens up a number of tantalizing possibilities,and yes..one of these is whether life has a part in it. MY opinion,i dare say ,it makes more sense that life which might exist underground or lies dormant on martian surface..subsurface comes to life along with geological activity. Some scientists explain the ancient huge water channel flows we see today on the surface by such EPISODIC rather than continuos geological activity...some dare even say that this could happen again today if magma hits a huge subsurface water reservoir resulting in chaotic regions and huge water flows...remember that outgassing of volcanic gases raise pressures and temperatures temporarily to allow liquid water to exist on the surface.the question would be for how long will the water be able to exist in liquid form and hence determine the size of the water channel!The huge sizes of ancient flows of course fits pretty well if we assime that atmospheric pressures and temperatures were higher in earlier martian history compared to the present day on Mars.

SBird · 2004-03-29 13:38:33

Cindy posted some great pics a while back showing dust devil tracks on the top of Olympus Mons where there isn't enough atmosphere to make a dust devil now. Meteoric dating puts those tracks at less than 3 million years old. I think that it's quite likely that Mars undergoes episodic warmings. If that's the case, if any life existed on Mars, it's almost certainly still there, hibernating or in hot springs.

These episodic warmings also raise hopes that Mars can be successfully terraformed - obviously, the polar caps and ground containenough sequestered gas to reconstitute quitea bit of atmosphere.

Julius Caeser · 2004-03-29 15:08:32

Were they pics of dust devils or sand dunes?Cant remember.But i believe the dunes are not for certain they are made up of dust we normally see in the lava plains below where the air is sufficient to allow for dust transfer.Am i right or wrong?

SBird · 2004-03-29 15:25:19

The pics were of dust devil tracks, I can't remember if there were dunes as well.

Julius Caeser · 2004-03-29 15:39:57

i would be grateful if u found that pic for me..thanks

SBird · 2004-03-29 16:16:07

[=http://www.newmars.com/forums/viewtopic.php?t=3086]Here you go. Goiong back and re-reading the thread, it looks like the dust devil tracks might be going on now but I think tha argument still stands.

~Eternal~ · 2004-03-29 20:20:22

How about this possibility :
Mars has been weighed and judged suitable for carbon based life, thus an alien species has decided to begin terraforming Mars and posssibly sharing it with Humans

SBird · 2004-03-29 22:31:57

Well, DUH - they picked up a copy of Case of Mars and said, "Hey, that looks pretty easy! I'm not doing anything this weekend, wanna fix up that planet?"
"Aw, I was going to hang out with my friends and put crop circles in some more fields..."
"C'mon, you did that last week, this'll let me get my Larva Scout terraforming patch!"

Shaun Barrett · 2004-03-29 22:51:56

Ha ha !! :laugh:

I particularly enjoyed the "Larva Scout" bit. (A creepy but funny thought.)

ERRORIST · 2004-03-30 11:19:16

As I predicted the spheres were hematite way before the announcement. One way for hematite to form in those formations is if they took over a biological organism through diagenisis. Normally hematite forms trigonal or hexagonal formations if not biological. I bet life still exists under the surface. Caves would also be good locations as well as underground thermal activity.

SBird · 2004-03-30 12:34:23

Caeser - My mistake, there isn't a picture for those Olympus Mons devil tracks. It was just a report of the tracks. No pictures, I'm afraid. However, there area lot of cool dust devil tracks on that thread so it's worth a gander anyways.

ERRORIST - The hematite nodules do look promising. Although there are non-biological formation processes for spherical hematite, the 'blueberries' are suggestive of some sort of biological activity.

John_McGowan · 2004-03-31 00:18:27

Regarding possible methane on Mars, please see my paper "Oil and Natural Gas
on Mars" from 2000.

Oil and natural gas on Mars
John F. McGowan III, "Oil and natural gas on Mars," in Instruments, Methods,
and Missions for Astrobiology III, Richard B. Hoover, Editor, Proceedings of
SPIE Vol. 4137, pp. 63-74 (2000).

ABSTRACT

On Earth, according to conventional theory, the largest, by mass and volume,
identifiable trace of past life is subsurface oil and natural gas deposits.
Nearly all coal and oil on Earth and most sedimentary source rocks
associated with coal, oil, and natural gas contain molecules of biological
origin and is proof of past life. If Mars possessed an Earth-like biosphere
in the past, Mars may contain subsurface deposits of oil and natural gas
indicating past life. Life might still exist in these deposits. Subsurface
oil and natural gas on Mars would probably cause seepage of hydrocarbon
gases such as methane at favorable locations on the Martian surface.
Further, if Mars contains substantial subsurface life, the most detectable
signature of this life on the Martian surface would be gases generated by
the life percolating up to the surface and venting into the Martian
atmosphere. In this paper, systems that can detect evidence of subsurface
oil and gas, including ground penetrating radar and infrared gas sensors are
explored. The limitations and future prospects of infrared gas detection and
imaging technologies are explored. The power, mass, and volume requirements
for infrared instruments able to detect venting gases, especially methane,
from an aerobot is estimated. The maximum range from the infrared sensor to
the gas vent and the minimum detectable gas density or fraction of the
Martian atmosphere - as appropriate for the instrument type - is estimated.
The bit rate and bit error rate requirements for transmitting the data back
to Earth are also estimated.

[http://www.jmcgowan.com/mars_reprint.PDF]http://www.jmcgowan.com/mars_reprint.PDF

Sincerely,

John McGowan

SBird · 2004-03-31 03:48:31

I'll try to read your paper sometime in the next few days. In the meantime, have you looked at the Mars Reconnaissance Orbiter subsurface radar? It's supposed to be able to detect ice up to a kilometer down. I know that organics have a small radar cross section but do you think that this owuld pick them up at all?

C M Edwards · 2004-03-31 09:19:00

It's interesting to note that two other bodies in the solar system, besides Mars, have atmospheric methane concentrations which are out of chemical equilibrium: Earth and Titan. Both have known chemical processes at work which should oxidize or reduce methane quite quickly in geologic terms, yet both have methane. Maybe Mars, Earth and Titan all derive their methane from the same source.

As for the hematite "concretions" found in Eagle crater, I have a hypothesis: I suspect that these globules were not formed by diagenesis _or_ seeded deposition from aqueous solution, but are rather a Martian equivalent of terrestrial stromatalites, and were formed by isolated colonies of iron-oxidizing chemosynthetic bacteria for which hematite was a waste product of their metabolism. Judging from known examples of iron-metabolizing bacteria, methane is also a likely waste productof their metabolism. Similar extremophiles are known to exist on Earth, so why not Mars?

This hypothesis could explain the observed upper limit to the size of the hematite blueberries found on Mars. Deposited concretions need not necessarily have such a limit.

Are there any suggestions for testing such a hypothesis? For example, would a globular stromatolite be porous in comparison to a deposited concretion? What are the distinctive characteristics of a stromatolite, created by living bacteria, compared to a concretion created by inanimate processes?

Julius Caeser · 2004-03-31 11:35:03

So i take it that Mars Express subsurface radar imaging wont be able to differentiate between underground water from hydrocarbon deposits.Is that right?Correct me if i'm wrong,i believe the radar is capable of penetrating 4 km underground..so any oil deposits should also be detected except we wont know for sure its composition.Congratulations to John ,,interesting work u've done there!

SBird · 2004-03-31 14:47:01

Interesting idea. I suppose that if they were anything like Earth stromatolites, you would see a very strong layering effect. Also, you'd expect to see various types of isotopic enrighment for, say O16 over O18. Unfortunately, the present rovers don't have the capacity to do those experiments.

ERRORIST · 2004-03-31 21:12:26

I suspect that these globules were not formed by diagenesis _or_ seeded deposition from aqueous solution, but are rather a Martian equivalent of terrestrial stromatalites, and were formed by isolated colonies of iron-oxidizing chemosynthetic bacteria for which hematite was a waste product of their metabolism.

Whatever they are , are they fossilized?

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Re: Methane on Mars - Proof for life on Mars?

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Re: Methane on Mars - Proof for life on Mars?

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Re: Methane on Mars - Proof for life on Mars?

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