Mars Express's OMEGA uncovers possible sites for life

- Press Release

- Press Images

Oh, gee -- do NOT get me started on the irrational European convention of "thousand million" when the proper term is "billion." The linked article uses *both* terms.

Do we speak of a hundred-fifty-hundred of anything? Of three-thousand-thousands? Of a million-billion?

Every three digits, the convention calls for the numbering identifier to change. Why, oh why, do the Europeans insist on making an exception when it comes to billions????

-the other Doug

Interesting. They classify three new ages within the Noachian era (between 4.5 to about 3.6 billion years).

<< The earliest, named by the authors as the 'phyllosian' era, occurred between 4.5–4.2 billion years ago, soon after the planet formed. The environment was possibly warm and moist at this time, allowing the formation of large-scale clay beds, many of which survive today.

The second era, the 'theiikian', took place between 4.2 and 3.8 billion years ago. It was prompted by planet-wide volcanic eruptions that drove global climate change. In particular, the sulphur these eruptions belched into the atmosphere reacted with the water to produce acid rain, which altered the composition of the surface rocks where it fell.

Finally, there was the 'siderikian', the longest lasting of the Martian eras. It began sometime around 3.8–3.5 billion years ago and continues today. There is little water involved in this era; instead, the rocks appear to have been altered during slow weathering by the tenuous Martian atmosphere. This process gave Mars its red colour. >>

A side trip into etymology.

"Phyllo_sian" has to do with phyllosilicates (clays).

"Sider_ikian" has to do with iron.

But I've dug around and can't find the root for "thei-ikian". Any ideas?

--Bill

Doug,

Using both terms is poor, I agree. The use of "thousand million" is to try and disambiguate the two
interpretations of the word "billion". The problem is that some countries use "short scale"
numbering, where a billion is a thousand million, and some use "long scale", where a billion is a
million million. See here for more on
this.

I was educated as a scientist, so now I always think in the "short scale", where things go up in three
orders of magnitude. But that said, I do have vague memories of being at school and thinking
that "of course a billion is a million million". It just sounded right. (and I'm still not quite
sure what a gazillion is ).

Also, remember that this is a press release, so they're going to steer away from using terms like
gigayears. The fact that such prefixes are in common use by people when talking about computers
does NOT mean that they are well understood. (We're special here, so we understand).


Chris

Possible link between 2 threads?? Latest ESA press release image caption reads "The hydrated minerals are not found in the channel as one would expect but in the eroded flanks and cratered plateau" this taken togethert with recent posts in 'Europa's subsurface ocean' suggest the following scenario:

1. Clay sediments are formed on Martian ocean bed. 2. Ocean freezes, but channels are eroded though the sediments by sub-glacial rivers. 3. Frozen ocean sublimes away leaving surface exposed to cratering.

What say the experts?

At the University,an Astronomer talk about the life of the stars :
"The sun is gona die in about 5 Billions years..."
A student jump and shout :
"How many years did you say ?"
"I said 5 Billions"
The student sit down with a sigh of relief
'Gosh, I understood 5 Millions..."

Much better in French : Millions & Milliards

[quote name='climber' - QUOTE removed - avoid quoting when replying to it - see forum guidelines
[/quote]

Ah yes, the old apocryphal story. It also usually involves an old man
or woman asking the question and responding. Same with the famous
"It's turtles all the way down" bit about what supports Earth.

Hydrated minerals anybody? No?
Tranquillisers all round then . . .

Instead of hoping for weak little Earth-like creatures just barely surviving under
some Martian rock, how about the chance that some ancient Martian life adapted
to its changing environment and has left descendants existing as a tough colony of
buggers living today on the Red Planet that can survive with little water, little air,
seriously cold temperatures, and laugh at direct ultraviolet radiation?

Has anyone really looked into creatures that could exist like that? Because if we
keep assuming Martian life is going to be a lot like Earth life, then I doubt there
will be anything to find on Mars except some very old fossils.

This billion problem is due to the fact that in some languages the interval between the 'llions is 10^3 while in other it is 10^6. Neither is really more logical than the other.

In Swedish it runs:

biljon 10^12
triljon 10^18
kvadriljon 10^24
kvintiljon 10^30

and so on, while 10^9 is "miljard", like in french.

tty

If I understand well these results, there were -perhaps- conditions favourable to appearance of life on Mars for two hundred millions years. If we consider the appearance of life like a process of random steps (as I discuss in another thread) where each step duration is in invert proportion of the probability to pass to the further step, and if we consider that the two first steps (self-replicating molecules and DNA code) were achieved in at last one billion years on Earth, then we can have some hint for a weak probability to find microbes, and a null probability to find insects ("bugs") which, on Earth, took 4 billions years to appear, even with permanently stable favourable conditions. We can even bet that the conditions on Mars were harder than on Earth. For instance if Mars had only temporary water bodies, the probability to have even simple thing like self-replicating molecules becomes very weak. Life needs permanently favourable conditions.

So what we can expect o find is very probably some self-replicating molecule systems, without DNA (or any equivalent). But as you say, if they are still alive today, they may be tough, with four billion years of selection:
-Able to dessicate, and still recover.
-laughing at UVs.
-able to bear low temperatures and to recover.
-or none of these, because they hide deep underground.

or none of this, because they live deep under earth.

Such systems may left traces in ancient clays, or in recent water eruption (without a volcanic origin). Eventually they may look like cells, but without DNA (or equivalent code-bearing molecules). If so, it would be enough to water a sample of recent water sediment to see sort of cells spouting around, and examine them with a microscope imager. But I don't expect too much...

Bill:

The volcano Thera in the Aegean?



other Doug:

So why isn't a Googoolplex just a thousand Googools?

And why is 'abbreviation' such a l-o-o-o-n-g word?

Bob Shaw

Same in German:
Million = 10^6
Milliarde = 10^9
Billion = 10^12
Billiarde = 10^15
Trillion = 10^18
Trilliarde = 10^21
...

That sometimes confuses German journalists when they try to translate English articles
Michael

Milliarde = 10^9
Billion = 10^12
Billiarde = 10^15
Trillion = 10^18
Trilliarde = 10^21


You're not talking about 2008's NASA budget, are you ?

It's kind of like the French calling seventy, sixty-ten (soixante-dix ) or eighty, four twenties (quatre-vingts). It's just cultural and linguistic tradition. I wouldn't lose any sleep over it.

Chris: "...It just sounded right. (and I'm still not quite sure what a gazillion is ).

Gadzillion, similar to buh'zillion. 1, followed by a "sufficient" number of: ",000"'s

How many is "One Sagan"?

Billions and Billions!

What is the S.I. unit of Beauty? One mili-Helen. The face of Helen was sufficient to launch a thousand ships, according to homer. One milihelen is sufficient beauty to launch one ship.

[quote name= quote in reply - removed
[/quote]

Ah, at last a rational definition of beauty.

Now is just lacking a convertion from the Helen beauty unit to bucks, for indemnities in divorce cases .

And if an Helen was to launch a ship, a wooden old dromon, how many Helen to launch a spaceship to Mars? Perhaps it is much less expensive than with rockets

Bill:

From Spaceflight Now:

"The eras are named after the Greek words for the predominant minerals formed within them. The one most likely to have supported life was the phyllosian, when clay beds could have formed at the bottom of lakes and seas, providing the damp conditions in which the processes of life could begin."


Bob Shaw

apparently, it means sulfur.

Ngunn:

I dunno about the experts, but that sounds very credible to me! A good, simple, explanation for an observed phenomenon...

Bob Shaw

Greek 'theion' = sulfur

tty

Not only European insists but also all latin america countries follow the same metric nomeclature. I don't know what is the metric for Southeast of Asia and Africa.
1 one
10 ten
100 one hundred
1,000 one thousand
10,000 ten thousands
100,000 one hundred thousands
1,000,000 one million
10,000,000 ten millions
100,000,000 one hundred millions
1,000,000,000 one thousand millions
10,000,000,000 ten thousand millions
100,000,000,000 one hundred thousand millions
1,000,000,000,000 one billion (thousand thousand millions)

In Spanish we call:
Millon = 10^6
Milliardo = 10^9
Billion = 10^12
Billiardo = 10^15
Trillion = 10^18
Trilliardo = 10^21

Rodolfo

On looking again at the map of the very small patches of different hydrated minerals found on Mars by OMEGA, I still think the OMEGA team may be wrong in saying that the sulfates were caused by an actual increase in Mars' volcanic activity during the Hesperian period.

Benton Clark's view, by contrast, has been that Mars' generally stronger volcanism during its earliest days -- combined with the fact that its lack of an ozone layer allowed solar UV light to penetrate all the way to the surface -- caused sulfuric acid to form all over early Mars' surface. In its earliest Noachian days, however, there could be a lot of phyllosilicate clays produced by nonacid water simply because the planet had a lot more liquid water in general all over its surface and so the acid was highly diluted. But during the Hesperian -- at which point Mars' initial dense atmosphere had vanished -- the planet's surface had become so cold that non-acid water could no longer be liquid there, making it possible for water to be liquid on the surface only where it was mixed with a lot of H2SO4 as antifreeze.

The OMEGA map does show the small dots of phyllosilicates to be sprinkled pretty randomly all over the planet, while the sulfate deposits are concentrated entirely around the Valles Marineris and the Meriaiani drainage area at its east end -- but this distribution also fits Clark's alternative model well, since by then most of Mars' remaining volcanic activity unquestionably WAS in the Tharsis region, regardless of whether or not it was actually stronger then than Mars' volcanism had been during the Noachian.

http://www.sciencemag.org/cgi/content/full/312/5772/400 (Figure 3)

Ah, but the lack of an early Martian ozone layer is an assumption. Just as is the lack of an early Martian magnetic field. The latter seems to be on really thin ice -- I think we need to question the former assumption, as well.

-the other Doug

No, it's not. To build up a strong ozone layer, you need LOTS of molecular oxygen in the air. Earth didn't have that either, until photosynthesis came along. (Until then, Earth's sizable supply of bacteria had to hide in the depths, and reproduce at a high enough rate that it could outstrip the part of their population that died when it drifted to the surface of the water.)

Granted that when a planet is losing its water to UV photolysis at a high rate, it can get a modest amount of O2 in the air, and thus build up a rather weak ozone layer, (Venus, because of its initial warmth lofting so much of its water vapor into the atmosphere, may perhaps have lost its water this way so fast that its ozone layer was actually, if briefly, rather impressive.) But any such Martian O3 layer would also have vanished when most of its water was lost either to photolysis or to freezing solid in the subsurface, which had certainly happened by the time of the Hesperian. (Come to think, of it, that's one reason why overall atmospheric production of sulfuric acid MIGHT have increased in the Hesperian, separately from the OMEGA team's suggestion that the planet's overall volcanic activity was actually stronger then.)

Sorry to interject an elementary question here, but could someone please post a quick summary of Martian geological epochs vs. years BP for reference? I am utterly lost with respect to the eras cited in this discussion, and I suspect that other readers would also appreciate the reference. Thanks!

Look on post #24 and scroll down to fig. 5.

Actually, that figure does not list the estimated years of the Noachian, Hesperian and Amazonian periods -- which are admittedly still pretty vague (they're based on estimates of cratering rates, and the Hesperian/Amazonian transition date in particular is extremely uncertain). One table can be found at http://www.lpi.usra.edu/meetings/lpsc2005/pdf/1843.pdf (Fig. 1). A clearer summary is at http://www7.nationalacademies.org/ssb/MarsACh04.pdf .

Thanks to you both, gentlemen; that was most helpful!

Clearly, we need to find some index fossils in order to resolve era boundaries more effectively...

Of course, index geochemical/geophysical events may well be the best we'll ever do. By any chance, will MSL have an instrument designed to measure critical isotope ratios for dating purposes?

Actually, we've had a thread on this earlier ("Rock dating experiments" over in the "MSL 09" section). It won't have an instrument explicitly for that purpose -- but I now think it might be able to test the feasibility of K-Ar dating indirectly. You'll recall that there was going to be an attempt to do this on Beagle 2, by using its X-ray spectrometer to measure K in the local rocks while its main GCMS package roasted rock samples and analyzed the gases released, which would have included Ar-40. Well, I believe MSL's experiments will have the same capability -- it has two separate experiments capable of measuring K, and I believe its "SAM" GCMS package can, like Beagle's, measure Ar-40 from ground-up and roasted rock samples. It's probably worth my time to look into this.

There are at least two teams working on explicit Mars age-dating instruments that would use various techniques --
http://www.lpi.usra.edu/meetings/lpsc2001/pdf/1492.pdf
http://www.lpi.usra.edu/meetings/robomars/pdf/6165.pdf
http://www.lpi.usra.edu/meetings/lpsc2005/pdf/1843.pdf
-- and Swindle's instrument would have been the main experiment on the "Urey" Mars Scout proposal:
http://trs-new.jpl.nasa.gov/dspace/bitstre...3/1/02-3063.pdf . Moreover, it seems to me that MSL's separate instruments do combine all the capabilities of the different components of the Urey age-dating experiment -- which would have tried to do not only K-Ar but cosmic-ray exposure age-dating.

It's also a fact that, a few years ago, COMPLEX listed this as one of the most important areas being neglected by the US Mars program as it was then designed. A few weeks ago, going through the Web documents on the question of how secondary craters may interfere with crater-count age estimates, I ran across one such abstract that recommended rough in-situ age-dating in 2 or 3 places on Mars' surface to settle the dispute.

Why, that's just fascinating, Bruce -- especially since, to my own question about this (likely in the thread to which you refer), I was rather loftily informed that the sample handling and preparation requirements for *every* existing rock dating technique require a delicacy of manipulation that unmanned probes would simple never achieve.

What changed?

-the other Doug

Well, here's my one entry (March 18, 2005) on that subject in that thread. ((You didn't have any entries on that thread; if I made a comment on the subject anywhere else, I don't remember.)

"More seriously, there IS a lot of interest in trying to develop a system that could at least crudely age-date Mars rocks in-situ -- and, in fact, such an instrument (designed by Timothy Swindle) was the main instrument on the proposed "Urey" Mars Scout mission. The plans are to utilize either K-Ar dating or Rb-Sr dating, by grinding up a rock sample and then firing a laser beam at it to volatilize the argon and those trace metals (with their relatively low vaporization points) out of the rock for mass spectrometric analysis. (Indeed, Beagle 2 -- with its X-ray spectrometer to measure potassium and its main system of rock grinders, ovens and mass spectrometer to measure argon-40 -- would have made a crude attempt at such dating.)

"Even an accuracy to within 200 or 300 million years would be extremely useful in answering a lot of the most important Mars questions -- and it would also be very useful on Venus and Mercury landers. (Indeed, the possible development of such an instrument was listed by the National Research Council back in 2001 as one of the most important missing items in the Mars exploration program as it was then designed.) But such a gadget will be heavy -- it was, as I say, the central instrument on the Urey lander -- and so, even if a fully successful design can be developed, flying it won't be that easy. I think it possible that such a device might be put on the second MSL, for instance -- but not until the first MSL and the other missions of the same period have given us a better overall idea of just what instruments SHOULD be put on such later Mars rovers."

I don't know whether that's "lofty", but it's certainly true that when I wrote it I wasn't putting in nearly enough thought on what the instruments on the first MSL -- not designed for age-dating though they are -- might nevertheless be able to do. As far as I can tell from looking at the design for the Swindle team's proposed "AGE" (Argon Geochemistry Experiment), every function it has will be duplicated by some part of the existing payload on MSL-1. (You'll notice also that I misdescribed Swindle's particular instrument; it would measure the argon just by grinding up the rock and roasting it in a GCMS oven, and the potassium using an internal LIBS spectrometer -- for which the three separate element-analyzing instruments on MSL-1 may be a fully adequate substitute. It's the other proposed Mars age-dating instrument -- designed by a U. of Hawaii team, and doing Rb-Sr age-dating -- that uses a laser to boil those two volatile elements out of rock samples.) They may not have the same level of measurement accuracy as the components of AGE, though. This is definitely worth our looking into. At a minimum, the first MSL may be able to give us a better idea of just how feasible in-situ age-dating on Mars actually is.

It was definitely in another thread, then. I recall asking about the feasibility of doing any actual rock dating in situ, and got told that all of the current dating techniques require extremely meticulous handling that just can't be done robotically. I recall expressing doubt about that conclusion, but was assured that we were a long away from such a feat...

I'm *very* glad to see that there are people who are thinking outside the box and coming up with inventive ways of dating rocks in situ. Let's hope these analyzers are available and sitting on Mars sometime relatively soon (like, say, within my lifetime... )

-the other Doug

Once again, we're talking about really fuzzy dating -- with an accuracy level of only about 10-20% -- but, as the papers on the subject point out, even that could be extremely valuable in understanding just what the general course of geologial evolution of a planet has been.

In situ dating rock age measure would be a great improvement since up to know, the only way is to return the sample to Earth to be able to date the rock's age.

Rodolfo