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Hydrated minerals map, MEx uncovers possible sites for life
SigurRosFan
post Apr 21 2006, 11:35 AM
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Mars Express's OMEGA uncovers possible sites for life

- Press Release

- Press Images


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dvandorn
post Apr 21 2006, 11:46 AM
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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


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SigurRosFan
post Apr 21 2006, 12:07 PM
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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. >>


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Bill Harris
post Apr 21 2006, 12:55 PM
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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


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chris
post Apr 21 2006, 01:15 PM
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QUOTE (dvandorn @ Apr 21 2006, 12:46 PM) *
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.


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 smile.gif ).

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
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ngunn
post Apr 21 2006, 01:33 PM
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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?
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climber
post Apr 21 2006, 01:39 PM
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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 tongue.gif


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ljk4-1
post Apr 21 2006, 02:00 PM
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[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.


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"After having some business dealings with men, I am occasionally chagrined,
and feel as if I had done some wrong, and it is hard to forget the ugly circumstance.
I see that such intercourse long continued would make one thoroughly prosaic, hard,
and coarse. But the longest intercourse with Nature, though in her rudest moods, does
not thus harden and make coarse. A hard, sensible man whom we liken to a rock is
indeed much harder than a rock. From hard, coarse, insensible men with whom I have
no sympathy, I go to commune with the rocks, whose hearts are comparatively soft."

- Henry David Thoreau, November 15, 1853

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ngunn
post Apr 21 2006, 02:55 PM
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Hydrated minerals anybody? No?
Tranquillisers all round then . . .
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ljk4-1
post Apr 21 2006, 05:34 PM
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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.


--------------------
"After having some business dealings with men, I am occasionally chagrined,
and feel as if I had done some wrong, and it is hard to forget the ugly circumstance.
I see that such intercourse long continued would make one thoroughly prosaic, hard,
and coarse. But the longest intercourse with Nature, though in her rudest moods, does
not thus harden and make coarse. A hard, sensible man whom we liken to a rock is
indeed much harder than a rock. From hard, coarse, insensible men with whom I have
no sympathy, I go to commune with the rocks, whose hearts are comparatively soft."

- Henry David Thoreau, November 15, 1853

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tty
post Apr 21 2006, 05:36 PM
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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
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Guest_Richard Trigaux_*
post Apr 21 2006, 05:59 PM
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Guests






QUOTE (ljk4-1 @ Apr 21 2006, 05:34 PM) *
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.



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...
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Bob Shaw
post Apr 21 2006, 08:10 PM
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QUOTE (Bill Harris @ Apr 21 2006, 01:55 PM) *
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


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


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MichaelT
post Apr 21 2006, 08:54 PM
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QUOTE (tty @ Apr 21 2006, 05:36 PM) *
biljon 10^12
triljon 10^18
kvadriljon 10^24
kvintiljon 10^30
and so on, while 10^9 is "miljard", like in french.


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 rolleyes.gif
Michael
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climber
post Apr 21 2006, 09:46 PM
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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 ?


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