Finding of perchlorates on Mars may provide a "life" explanation of the Viking results.
Robert Clark
Perchlorate find still needs confirmation; it wouldn’t rule out
habitability.
By Alan Boyle
Science editor
MSNBC
updated 8:11 p.m. ET, Tues., Aug. 5, 2008
"However, some organisms actually thrive on perchlorates and have been
enlisted for cleaning up chemical spills. Perchlorate-loving microbes
have been found in Chile's Atacama Desert and Antarctica — two of the
places that have been compared to the Red Planet's cold, dry
environment."
http://www.msnbc.msn.com/id/26043028/
I had written a post to the space forum Bautforum.com arguing that
perchlorate-metabolizing organisms might provide a "life" explanation
of the Viking Gas Exchange Experiment:
Possibilities for life on Mars - a surprising new microbe.
22-January-2005, 05:40 PM
Possibilities for life on Mars - a surprising new microbe.
RGClark
http://www.bautforum.com/life-space/15752-possibilities-life-mars-surprising-new-microbe.html
The three biology experiments on Viking were the Labeled Release
Experiment, the Pyrolytic Release Experiment, and the Gas Exchange
Experiment. Oxygen evolution was detected by the Gas Exchange
Experiment, which the perchlorate-metabolizing microbes are able to
do. The Labeled Release Experiment detected CO2 being evolved. Some
strains of the microbe do evolve CO2 instead of oxygen. The third
experiment the Pyrolytic Release Experiment detects production of
organic molecules by incorporation of atmospheric gases. Some strains
of the microbe are able to survive with just CO2 as their sole carbon
source, so would incorporate atmospheric CO2 into their organic
makeup. Then the perchlorate-metabolizers could be responsible for the
positive life signs seen in all three Viking life experiments.
According to the MSNBC article the perchlorate-metabolizers have been
seen in both the Atacama desert and in Antarctica.
Then tests of the soils from these sites containing the perchlorate-
metabolizers using analog instruments of the three Viking life
experiments may show that life is indeed possible as an explanation of
the Viking Mars-life experimental results.
Bob Clark
dlzc
On Aug 6, 1:04 pm, Robert Clark <rgregorycl...@yahoo.com> wrote:
> Scientists: Martian soil similar to Chile’s desert.
> Perchlorate find still needs confirmation; it wouldn’t
> rule out habitability.
Since (a small) part of the reason we are looking for water on Mars is
to allow production of fuel and oxidizer for a return manned trip from
Mars, I wonder if this can provide a suitable oxidizer, or is the
concentration too low?
David A. Smith
Andrew Usher
> Scientists: Martian soil similar to Chile’s desert.
> Perchlorate find still needs confirmation; it wouldn’t rule out
> habitability.
It's interesting that no nitrate was found. Any oxidant that can
produce perchlorate can also make nitrate, and one would
expect the latter to be more abundant. The perchlorate may
have been deposited by water, but I still couldn't understand
why nitrate would not be.
Andrew Usher
hhc...@yahoo.com
Andrew, the failure thus far to find nitrates on Mars tends to suggest
that there were never advanced forms of organic life on the planet,
and that its atmosphere was not rich in nitrogen.
Again, what is the chemical composition of the Mars atmosphere?
Harry C.
dlzc
Nitrogen barely exists in the atmosphere of Mars, has very low
solubility in water, and is *very* stable. Perchlorate is formed in
seawater (on Earth), and tends to reduce chloride ion (and hence
salinity).
The fact that there is no detectable nitrate means there are "no"
nitrogen fixing bacteria such as we'd recognize.
David A. Smith
Uncle Al
>
> Scientists: Martian soil similar to Chile’s desert.
Chile's Atacama desert is more sterile than an operating room.
Google
atacama sterile 22,40o hits
The only biologics there are either macroscopic ancient with roots
into a subterranean aquifer or microscopic brought in by scientists
studying the desert's sterility. Scientist A takes a dump, Scietist B
discovers a whole new microecology. Scientist C has dandruff,
Scientist E publishes on the incidence of squamous cells.
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/lajos.htm#a2
Dirk Bruere at NeoPax
> Robert Clark wrote:
>> Scientists: Martian soil similar to Chile’s desert.
> [snip crap]
>
> Chile's Atacama desert is more sterile than an operating room.
>
> atacama sterile 22,40o hits
> The only biologics there are either macroscopic ancient with roots
> into a subterranean aquifer or microscopic brought in by scientists
> studying the desert's sterility. Scientist A takes a dump, Scietist B
> discovers a whole new microecology. Scientist C has dandruff,
> Scientist E publishes on the incidence of squamous cells.
Took your advice
http://wwwpaztcn.wr.usgs.gov/rsch_highlight/articles/200411.html
"In 2003, scientists reported that the driest Atacama soils were
sterile. Not so, reports a team of Arizona scientists. Bleak though it
may be, microbial life lurks beneath the arid surface of the Atacama's
absolute desert. "
--
Dirk
http://www.transcendence.me.uk/ - Transcendence UK
http://www.theconsensus.org/ - A UK political party
http://www.onetribe.me.uk/wordpress/?cat=5 - Our podcasts on weird stuff
dlzc
On Aug 6, 3:36 pm, Dirk Bruere at NeoPax <dirk.bru...@gmail.com>
wrote:
> Uncle Al wrote:
> > Robert Clark wrote:
> >> Scientists: Martian soil similar to Chile’s desert.
> > [snip crap]
>
> > Chile's Atacama desert is more sterile than an
> > operating room.
... witness MRSA ... something more sterile than something that
*isn't* sterile, isn't really saying much.
> > Google
> > atacama sterile 22,40o hits
> > The only biologics there are either macroscopic
> > ancient with roots into a subterranean aquifer or
> > microscopic brought in by scientists studying
> > the desert's sterility. Scientist A takes a dump,
> > Scietist B discovers a whole new microecology.
> > Scientist C has dandruff, Scientist E publishes
> > on the incidence of squamous cells.
>
> Took your advice
http://wwwpaztcn.wr.usgs.gov/rsch_highlight/articles/200411.html
>
> "In 2003, scientists reported that the driest
> Atacama soils were sterile. Not so, reports a
> team of Arizona scientists. Bleak though it
> may be, microbial life lurks beneath the arid
> surface of the Atacama's absolute desert. "
I blame "green ice".
http://www.canada.com/story.html?id=27df081f-aec2-4dca-97dd-e1b05b5ed1a6
... if only they could spell, eh.
David A. Smith
Robert Clark
wrote:
> Uncle Al wrote:
> > Robert Clark wrote:
> >> Scientists: Martian soil similar to Chile’s desert.
> > [snip crap]
>
> > Chile's Atacama desert is more sterile than an operating room.
>
> > atacama sterile 22,40o hits
> > The only biologics there are either macroscopic ancient with roots
> > into a subterranean aquifer or microscopic brought in by scientists
> > studying the desert's sterility. Scientist A takes a dump, Scietist B
> > discovers a whole new microecology. Scientist C has dandruff,
> > Scientist E publishes on the incidence of squamous cells.
>
>
> "In 2003, scientists reported that the driest Atacama soils were
> sterile. Not so, reports a team of Arizona scientists. Bleak though it
> may be, microbial life lurks beneath the arid surface of the Atacama's
> absolute desert. "
>
> --
> Dirk
>
>
Thanks for that. The image of the dry core of Atacama could be taken
as one from the surface of Mars:
http://wwwpaztcn.wr.usgs.gov/rsch_highlight/images/200411/fig1.jpg
Bob Clark
Andrew Usher
> Dear Andrew Usher:
>
> On Aug 6, 1:33 pm, Andrew Usher <k_over_hb...@yahoo.com> wrote:
>
> > On Aug 6, 3:04 pm, Robert Clark <rgregorycl...@yahoo.com> wrote:
>
> > > Scientists: Martian soil similar to Chile’s desert.
> > > Perchlorate find still needs confirmation; it
> > > wouldn’t rule out habitability.
>
> > It's interesting that no nitrate was found. Any oxidant
> > that can produce perchlorate can also make nitrate,
> > and one would expect the latter to be more abundant.
> > The perchlorate may have been deposited by water,
> > but I still couldn't understand why nitrate would not be.
>
> Nitrogen barely exists in the atmosphere of Mars, has very low
> solubility in water, and is *very* stable. Perchlorate is formed in
> seawater (on Earth), and tends to reduce chloride ion (and hence
> salinity).
So is it believe that the perchlorate formed in situ by oxidation
of chloride? What oxidant - ozone?
Actually the fact the no nitrates were found doesn't mean they
don't exist. If they form in the atmosphere they would deposit
uniformly over the surface, and would quite possibly be below
the detection limit. Does ozone react with N2 at all?
> The fact that there is no detectable nitrate means there are "no"
> nitrogen fixing bacteria such as we'd recognize.
Right. Which leaves the puzzle of where the N did go, still
unsolved I believe.
Andrew Usher
Andrew Usher
> Andrew, the failure thus far to find nitrates on Mars tends to suggest
> that there were never advanced forms of organic life on the planet,
> and that its atmosphere was not rich in nitrogen.
It must have been nitrogen-rich at one time. Or is it really possible
that Mars accreted almost no N2? I've wondered about the C/N
ratio of the terrestrial planets. The cosmic ratio is about 4:1,
Venus is 13:1 if you accept that all the C and N are in the
atmosphere now (likely), Earth seems to be near 50:1, and Mars
would be thousands to 1 in that case.
> Again, what is the chemical composition of the Mars atmosphere?
Not terribly relevant. If there is something in Mars's atmosphere
that could oxidise N2, it would, since the other major
constituents - CO2 and Ar - are inert to oxidation.
Andrew Usher
N:dlzc D:aol T:com (dlzc)
"Andrew Usher" <k_over...@yahoo.com> wrote in message
news:d9ebd39c-dfde-47bd...@d1g2000hsg.googlegroups.com...
...
>> Nitrogen barely exists in the atmosphere of Mars,
>> has very low solubility in water, and is *very*
>> stable. Perchlorate is formed in seawater (on
>> Earth), and tends to reduce chloride ion (and
>> hence salinity).
> So is it believe that the perchlorate formed in situ
> by oxidation of chloride? What oxidant - ozone?
Little free oxygen present, so probably not ozone. Presumably UV
and CO2 would liberate some monatomic oxygen that could do the
job.
> Actually the fact the no nitrates were found
> doesn't mean they don't exist.
... or don't exist at that pole ...
> If they form in the atmosphere they would deposit
> uniformly over the surface, and would quite
> possibly be below the detection limit. Does ozone
> react with N2 at all?
No. Nitrogen can act as a carrier for an oxygen atom for a short
period of time, but it either contacts an oxygen molecule (on
Earth) and makes ozone, or it contacts water vapor and becomes
(sort of) nitric acid.
>> The fact that there is no detectable nitrate means
>> there are "no" nitrogen fixing bacteria such as
>> we'd recognize.
> Right. Which leaves the puzzle of where the N did
> go, still unsolved I believe.
No reason Mars had to have a certain amount of nitrogen. There
is a tiny bit in its atmosphere...
Venus and Mars have a very low *percentage* of nitrogen, compared
with Earth. In fact, it looks like we have the lion's share
in-system.
David A. Smith
Andrew Usher
wrote:
> > If they form in the atmosphere they would deposit
> > uniformly over the surface, and would quite
> > possibly be below the detection limit. Does ozone
> > react with N2 at all?
>
> No. Nitrogen can act as a carrier for an oxygen atom for a short
> period of time,
Do you mean N2 + O -> N2O ?
> but it either contacts an oxygen molecule (on
> Earth) and makes ozone, or it contacts water vapor and becomes
> (sort of) nitric acid.
And nitric acid is what makes nitrates.
> >> The fact that there is no detectable nitrate means
> >> there are "no" nitrogen fixing bacteria such as
> >> we'd recognize.
> > Right. Which leaves the puzzle of where the N did
> > go, still unsolved I believe.
>
> No reason Mars had to have a certain amount of nitrogen. There
> is a tiny bit in its atmosphere...
>
> Venus and Mars have a very low *percentage* of nitrogen, compared
> with Earth. In fact, it looks like we have the lion's share
> in-system.
No! Venus has more N than Earth almost certainly. See my other
post in this thread where I mentioned C/N ratios, a mystery since
both are volatile.
Andrew Usher
N:dlzc D:aol T:com (dlzc)
"Andrew Usher" <k_over...@yahoo.com> wrote in message
news:0736b685-01f3-44cf...@f63g2000hsf.googlegroups.com...
> On Aug 6, 10:16 pm, "N:dlzc D:aol T:com \(dlzc\)"
> <dl...@cox.net>
> wrote:
>
>> > If they form in the atmosphere they would deposit
>> > uniformly over the surface, and would quite
>> > possibly be below the detection limit. Does ozone
>> > react with N2 at all?
>>
>> No. Nitrogen can act as a carrier for an oxygen
>> atom for a short period of time,
>
> Do you mean N2 + O -> N2O ?
More like N2O*... the oxygen is unstale and easily liberated by
visible light. What is measured at the outlet of a commercial
ozone generator with air as a feed gas is N2O, NO2, and N2O5...
and the amount of humidity controls how much of which. N2O5 can
still form ozone upon decay. The others cannot.
>> but it either contacts an oxygen molecule (on
>> Earth) and makes ozone, or it contacts water vapor
>> and becomes (sort of) nitric acid.
>
> And nitric acid is what makes nitrates.
But there is no free oxygen or humidity (currently) to do that.
>> >> The fact that there is no detectable nitrate means
>> >> there are "no" nitrogen fixing bacteria such as
>> >> we'd recognize.
>> > Right. Which leaves the puzzle of where the N did
>> > go, still unsolved I believe.
>>
>> No reason Mars had to have a certain amount of
>> nitrogen. There is a tiny bit in its atmosphere...
>>
>> Venus and Mars have a very low *percentage* of
>> nitrogen, compared with Earth. In fact, it looks
>> like we have the lion's share in-system.
>
> No! Venus has more N than Earth almost certainly.
> See my other post in this thread where I mentioned
> C/N ratios, a mystery since both are volatile.
OK. I accept that it has more in its atmosphere, in moles per
unit volume.
David A. Smith
Andrew Usher
wrote:
> Dear Andrew Usher:
>
> "Andrew Usher" <k_over_hb...@yahoo.com> wrote in message
>
> news:0736b685-01f3-44cf...@f63g2000hsf.googlegroups.com...
>
> > On Aug 6, 10:16 pm, "N:dlzc D:aol T:com \(dlzc\)"
> > <dl...@cox.net>
> > wrote:
>
> >> > If they form in the atmosphere they would deposit
> >> > uniformly over the surface, and would quite
> >> > possibly be below the detection limit. Does ozone
> >> > react with N2 at all?
>
> >> No. Nitrogen can act as a carrier for an oxygen
> >> atom for a short period of time,
>
> > Do you mean N2 + O -> N2O ?
>
> More like N2O*... the oxygen is unstale and easily liberated by
> visible light.
What? N2O is not that unstable. I don't think there's any other
bound state between N2 and O.
> >> but it either contacts an oxygen molecule (on
> >> Earth) and makes ozone, or it contacts water vapor
> >> and becomes (sort of) nitric acid.
>
> > And nitric acid is what makes nitrates.
>
> But there is no free oxygen or humidity (currently) to do that.
There's enough oxygen and water to ensure that NO is
ultimately absorbed by the surface into nitrates or nitrites.
> >> No reason Mars had to have a certain amount of
> >> nitrogen. There is a tiny bit in its atmosphere...
>
> >> Venus and Mars have a very low *percentage* of
> >> nitrogen, compared with Earth. In fact, it looks
> >> like we have the lion's share in-system.
>
> > No! Venus has more N than Earth almost certainly.
> > See my other post in this thread where I mentioned
> > C/N ratios, a mystery since both are volatile.
>
> OK. I accept that it has more in its atmosphere, in moles per
> unit volume.
Earth is though to have only 2-3 times the N found in its
atmosphere, so still less than Venus.
Andrew Usher
N:dlzc D:aol T:com (dlzc)
"Andrew Usher" <k_over...@yahoo.com> wrote in message
news:f0ec6c49-8fe6-40fc...@j7g2000prm.googlegroups.com...
> On Aug 7, 8:17 am, "N:dlzc D:aol T:com \(dlzc\)"
> <dl...@cox.net>
> wrote:
>> Dear Andrew Usher:
>>
>> "Andrew Usher" <k_over_hb...@yahoo.com> wrote in message
>>
>> news:0736b685-01f3-44cf...@f63g2000hsf.googlegroups.com...
>>
>> > On Aug 6, 10:16 pm, "N:dlzc D:aol T:com \(dlzc\)"
>> > <dl...@cox.net>
>> > wrote:
>>
>> >> > If they form in the atmosphere they would deposit
>> >> > uniformly over the surface, and would quite
>> >> > possibly be below the detection limit. Does ozone
>> >> > react with N2 at all?
>>
>> >> No. Nitrogen can act as a carrier for an oxygen
>> >> atom for a short period of time,
>>
>> > Do you mean N2 + O -> N2O ?
>>
>> More like N2O*... the oxygen is unstale and easily
>> liberated by visible light.
>
> What? N2O is not that unstable. I don't think there's
> any other bound state between N2 and O.
There is. The star is there for a reason. Calling it "bound" is
a joke. Maybe bound like hair to a balloon.
>> >> but it either contacts an oxygen molecule (on
>> >> Earth) and makes ozone, or it contacts water vapor
>> >> and becomes (sort of) nitric acid.
>>
>> > And nitric acid is what makes nitrates.
>>
>> But there is no free oxygen or humidity (currently) to
>> do that.
>
> There's enough oxygen and water to ensure that NO
> is ultimately absorbed by the surface into nitrates or
> nitrites.
The oxygen is bound to carbon (or in rock). The water
concentration is *really* low. The temperature is really low,
requiring even more activation energy. I don't see a
non-biological way of making nitrate with this atmosphere.
David A. Smith
Andrew Usher
wrote:
> >> > Do you mean N2 + O -> N2O ?
>
> >> More like N2O*... the oxygen is unstale and easily
> >> liberated by visible light.
>
> > What? N2O is not that unstable. I don't think there's
> > any other bound state between N2 and O.
>
> There is. The star is there for a reason. Calling it "bound" is
> a joke. Maybe bound like hair to a balloon.
Interesting. N2O is bound with respect to N2 + O, thermodynamically.
> >> >> but it either contacts an oxygen molecule (on
> >> >> Earth) and makes ozone, or it contacts water vapor
> >> >> and becomes (sort of) nitric acid.
>
> >> > And nitric acid is what makes nitrates.
>
> >> But there is no free oxygen or humidity (currently) to
> >> do that.
>
> > There's enough oxygen and water to ensure that NO
> > is ultimately absorbed by the surface into nitrates or
> > nitrites.
>
> The oxygen is bound to carbon (or in rock).
There's 0.11% oxygen in the Martian atmosphere.
> The water
> concentration is *really* low. The temperature is really low,
> requiring even more activation energy.
It doesn't much matter that concentrations are low. NO is
fairly stable, and lasts long enough to react.
> I don't see a
> non-biological way of making nitrate with this atmosphere.
Well, the literature contradicts you. The solar wind and
magnetosphere (which is rather well known) fixes N at
about 40,000 tons/yr through electron impact. This is
equal to 10 mb per billion years, a lot more than is currently
in the air.
Andrew Usher
Robert Clark
> Scientists: Martian soil similar to Chile’s desert.
> Perchlorate find still needs confirmation; it wouldn’t rule out
> habitability.
> By Alan Boyle
> Science editor
> MSNBC
> updated 8:11 p.m. ET, Tues., Aug. 5, 2008
> "However, some organisms actually thrive on perchlorates and have been
> enlisted for cleaning up chemical spills. Perchlorate-loving microbes
> have been found in Chile's Atacama Desert and Antarctica — two of the
> places that have been compared to the Red Planet's cold, dry
> environment."http://www.msnbc.msn.com/id/26043028/
>
> I had written a post to the space forum Bautforum.com arguing that
> perchlorate-metabolizing organisms might provide a "life" explanation
> of the Viking Gas Exchange Experiment:
>
> Possibilities for life on Mars - a surprising new microbe.
> 22-January-2005, 05:40 PM
> Possibilities for life on Mars - a surprising new microbe.
>
> The three biology experiments on Viking were the Labeled Release
> Experiment, the Pyrolytic Release Experiment, and the Gas Exchange
> Experiment. Oxygen evolution was detected by the Gas Exchange
> Experiment, which the perchlorate-metabolizing microbes are able to
> do. The Labeled Release Experiment detected CO2 being evolved. Some
> strains of the microbe do evolve CO2 instead of oxygen. The third
> experiment the Pyrolytic Release Experiment detects production of
> organic molecules by incorporation of atmospheric gases. Some strains
> of the microbe are able to survive with just CO2 as their sole carbon
> source, so would incorporate atmospheric CO2 into their organic
> makeup. Then the perchlorate-metabolizers could be responsible for the
> positive life signs seen in all three Viking life experiments.
> According to the MSNBC article the perchlorate-metabolizers have been
> seen in both the Atacama desert and in Antarctica.
> Then tests of the soils from these sites containing the perchlorate-
> metabolizers using analog instruments of the three Viking life
> experiments may show that life is indeed possible as an explanation of
> the Viking Mars-life experimental results.
>
In this article:
Reports
Mars-Like Soils in the Atacama Desert, Chile, and the Dry Limit of
Microbial Life.
Science 7 November 2003: Vol. 302. no. 5647, pp. 1018 - 1021.
http://www.sciencemag.org/cgi/content/full/302/5647/1018?ck=nck
the authors concluded the reactions they observed weren't due to life
since they couldn't detect any in the hyperarid core of the desert.
However, follow up observations by scientists were able to detect
microbes at very low levels even in the driest areas.
Interesting passage from the article:
"The redox potential (Eh) of several Atacama Desert samples was
oxidizing with values ranging from 365 to 635 mV. We performed
chemical assays for superoxides and hydrogen peroxide, because these
are the most plausible oxidants and are those suggested as
explanations for the reactivity observed by the Viking landers. Our
results rule out these oxidants as the cause of the reactivity seen at
the Yungay area, because the concentrations are too low (0.05 to 0.14
ppm) to explain our results and because the variation with latitude
does not follow the variation seen in the organic or microbial
concentrations. Nitrates are present in the soil in high levels (10 to
140 ppm), but they alone are not oxidizing enough to account for the
reactivity seen in our samples. Nitrates may lead to the formation of
peroxonitrite (NOO2–), and this has been suggested as a possible
martian oxidant (13). However, the nitrate concentrations needed are
in the percent level (10), much higher than in the Atacama. Thus,
although our results show the presence of a strong oxidant in the
soils in the Yungay area, the nature of the oxidant remains
unexplained."
Question: could the generation of oxygen by the perchlorate-
metabolizers in the Atacama be taken as indicating the high redox
potential?
Bob Clark
mrda...@gmail.com
> Scientists: Martian soil similar to Chile’s desert.
> Perchlorate find still needs confirmation; it wouldn’t rule out
> habitability.
> By Alan Boyle
> Science editor
> MSNBC
> updated 8:11 p.m. ET, Tues., Aug. 5, 2008
> "However, some organisms actually thrive on perchlorates and have been
> enlisted for cleaning up chemical spills. Perchlorate-loving microbes
> have been found in Chile's Atacama Desert and Antarctica — two of the
> places that have been compared to the Red Planet's cold, dry
> environment."http://www.msnbc.msn.com/id/26043028/
>
> I had written a post to the space forum Bautforum.com arguing that
> perchlorate-metabolizing organisms might provide a "life" explanation
> of the Viking Gas Exchange Experiment:
>
> Possibilities for life on Mars - a surprising new microbe.
> 22-January-2005, 05:40 PM
> Possibilities for life on Mars - a surprising new microbe.
>
> The three biology experiments on Viking were the Labeled Release
> Experiment, the Pyrolytic Release Experiment, and the Gas Exchange
> Experiment. Oxygen evolution was detected by the Gas Exchange
> Experiment, which the perchlorate-metabolizing microbes are able to
> do. The Labeled Release Experiment detected CO2 being evolved. Some
> strains of the microbe do evolve CO2 instead of oxygen. The third
> experiment the Pyrolytic Release Experiment detects production of
> organic molecules by incorporation of atmospheric gases. Some strains
> of the microbe are able to survive with just CO2 as their sole carbon
> source, so would incorporate atmospheric CO2 into their organic
> makeup. Then the perchlorate-metabolizers could be responsible for the
> positive life signs seen in all three Viking life experiments.
> According to the MSNBC article the perchlorate-metabolizers have been
> seen in both the Atacama desert and in Antarctica.
> Then tests of the soils from these sites containing the perchlorate-
> metabolizers using analog instruments of the three Viking life
> experiments may show that life is indeed possible as an explanation of
> the Viking Mars-life experimental results.
>
> Bob Clark
How much perchlorate are we talking about on Mars soil? 4 ppb? 10
ppm? 50% by mass?
Michael
Robert Clark
According to the recent Mars Phoenix news conference the mission
scientists have not yet quantified the amount of perchlorates in the
soil.
However in a previous news conference, prior to the discovery of the
perchlorates, they estimated the amount of salts overall in the Mars
soil at the Phoenix site as 1000 parts per million.
Bob Clark
Robert Clark
That report showed microbes exist even in the driest parts of the
Atacama but at 20 to 30 cm beneath the surface. Some other reports
have shown life exists in the hyperarid core of the Atacama even at
the surface:
Deliquescence in the Atacama.
Date Released: Monday, July 10, 2006
"While strolling through the salar, Wierzchos noticed a thin dirty
gray
layer along the edge of one of these salt rocks, a few millimeters
(about one-quarter of an inch) below its surface. Intrigued, he broke
off a piece of the rock and brought it back to the research station.
He
dissolved a bit of the material in water, placed a drop on a
microscope
slide, and took a look. He expected it to be some kind of mineral
contamination.
"Instead, what he saw were living cells. There was life, thriving,
inside dry salt rocks. He had discovered a previously unknown habitat
for life on Earth. Microbes had been discovered living in rocks
before.
And they'd been found living in extremely salty - wet and salty -
environments. But never inside dry salt rocks.
"In wet halite, okay,' says Wierzchos, citing the Dead Sea as an
example of a wet, salty environment where microbes have been found.
'But this is dry halite. This is totally different stuff."
http://www.astrobiology.com/news/viewpr.html?pid=20309
A Preliminary Survey of Non-Lichenized Fungi Cultured from the
Hyperarid Atacama Desert of Chile.
Date Released: Tuesday, August 22, 2006.
http://www.marstoday.com/news/viewsr.html?pid=21797 [abstract]
This last is interesting since some species of fungi have been shown
to survive at subfreezing temperatures in liquid water brines:
Brine organisms and the question of habitat-specific adaptation.
Origins of Life and Evolution of Biospheres.
Volume 14, Numbers 1-4 / December, 1984
"Abstract Among the well-known ultrasaline terrestrial habitats, the
Dead Sea in the Jordan Rift Valley and Don Juan Pond in the Upper
Wright Valley represent two of the most extreme. The former is a
saturated sodium chloride-magnesium sulfate brine in a hot desert, the
latter a saturated calcium chloride brine in an Antarctic desert. Both
Dead Sea and Don Juan water bodies themselves are limited in
microflora, but the saline Don Juan algal mat and muds contain
abundant nutrients and a rich and varied microbiota, including
Oscillatoria,Gleocapsa,Chlorella, diatoms,Penicillium and bacteria.
In such environments, the existence of an array of specific
adaptations is a common, and highly reasonable, presumption, at least
with respect to habitat-obligate forms. Nevertheless, many years of
ongoing study in our laboratory have demonstrated that lichens
(e.g.Cladonia), algae (e.g.Nostoc) and fungi (e.g.Penicillium,
Aspergillus) from the humid tropics can sustain metabolism down to
-40°C and growth down to -10°C in simulated Dead Sea or Don Juan (or
similar) media without benefit of selection or gradual acclimation.
Non-selection is suggested in fungi by higher growth rates from
vegetative inocula than spores. The importance of nutrient parameters
was also evident in responses to potassium and reduced nitrogen
compounds.
In view of the saline performance of tropicalNostoc, and its presence
in the Antarctic dry valley soils, its complete absence in our Don
Juan mat samples was and remains a puzzle.
We suggest that adaptive capability is already resident in many
terrestrial life forms not currently in extreme habitats, a possible
reflection of evolutionary selection for wide spectrum environmental
adaptability."
http://www.springerlink.com/content/r0565304t64835nv/
Life Sci Space Res. 1976;14:351-4.
Performance of fungi in low temperature and hypersaline environments.
Siegel SM, Speitel TW.
Department of Botany, University of Hawaii, Honolulu, Hawaii, USA.
"During the past ten years we have observed a broad array of stress
capabilities in common fungi including ability to grow in aqueous
ammonia and other alkaline solutions, in acids, in the presence of
heavy metals, and in various salt media at low temperature. This
report is concerned primarily with (a) the performance of
Aspergillaceae in a variety of saturated salts, (b) distinctive roles
for K+ and Rb+ ions, and (c) the lowest temperatures at which growth
in nutrient brines has been observed, namely 267 degrees K in as
little as 14 days. We also describe a novel solid medium based upon
gelatin, glycerol and water in which fungal cultures growing at 248
degrees K can be directly examined under oil-immersion magnification.
The performance capabilities of the fungi show that tolerance or
adaptability to harsh and extreme physical-chemical environments
cannot be considered a unique feature of prokaryotic life forms. Salt
flats, brine pools and other natural hypersaline environments have
long been recognized as real ecological niches harboring a range of
biota from pseudomonad bacteria and green algae to specialized
crustaceans. A notable omission in this ecological record is the
fungi, although the group is known to include marine forms."
http://www.ncbi.nlm.nih.gov/pubmed/12678120
Bob Clark
Robert Clark
> ...
>
> In this article:
>
> Reports
> Mars-Like Soils in the Atacama Desert, Chile, and the Dry Limit of
> Microbial Life.
Perchlorates themselves are oxidizing. So perhaps they were the cause
of high reduction potential seen in the Atacama soil. However,
perchlorates are supposed to be weakly oxidizing so it is uncertain if
they would be able to account for the redox potential seen in those
samples.
Interestingly the MECA instrument on Mars Phoenix also has the
capability of measuring redox potential:
THE 2007 PHOENIX MARS SCOUT MECA WET CHEMISTRY LABORATORY.
http://astrobiotech.arc.nasa.gov/abstracts/abstract_pdfs/Kounaves8.pdf
The particular type of oxidation-reduction reactions engaged in by
the perchlorate reducing organisms is unusual in that some steps are
involve "disproportionation" or "dismutation" in which a chemical
species is both oxidized and reduced at the same time:
Disproportionation.
http://en.wikipedia.org/wiki/Disproportionation
If the MECA wet chemistry experiment on Phoenix is able to detect
this that would be strong evidence that this type of organism is
involved.
Bob Clark
Robert Clark
> of high reduction potential seen in the Atacama soil. However,
> perchlorates are supposed to be weakly oxidizing so it is uncertain if
> they would be able to account for the redox potential seen in those
> samples.
> Interestingly the MECA instrument on Mars Phoenix also has the
> capability of measuring redox potential:
>
>
> The particular type of oxidation-reduction reactions engaged in by
> the perchlorate reducing organisms is unusual in that some steps are
> involve "disproportionation" or "dismutation" in which a chemical
> species is both oxidized and reduced at the same time:
>
>
> If the MECA wet chemistry experiment on Phoenix is able to detect
> this that would be strong evidence that this type of organism is
> involved.
>
The possibility of the perchlorate-metabolizing microbes being present
might have a bearing on the failure of the TEGA instrument on Phoenix
to detect free chlorine to confirm the presence of perchlorate. The
TEGA scientists looked only for chlorine gas. This was based on the
fact that free oxygen was detected from one of the samples. However,
the perchlorate-metabolizing microbes release oxygen in reducing
perchlorate to chlorate, then chlorite, then chloride. Then what might
be needed to search for instead might be one of these compounds. This
would require TEGA being programmed to search for them specifically
since in its normal mode of operation it does not do a wide spectrum
search but focuses on only certain expected compounds only.
Bob Clark
N:dlzc D:aol T:com (dlzc)
"Robert Clark" <rgrego...@yahoo.com> wrote in message
news:ee173208-e15e-43ea...@x41g2000hsb.googlegroups.com...
...
> However, the perchlorate-metabolizing microbes release
> oxygen in reducing perchlorate to chlorate, then chlorite,
> then chloride.
They release oxygen from that *molecule*, not to the air. They
use the oxygen like other bacteria do... to "breathe".
David A. Smith
Robert Clark
wrote:
> Dear Robert Clark:
>
> "Robert Clark" <rgregorycl...@yahoo.com> wrote in message
Some strains are anaerobic and therefore do not use oxygen. For these
the oxygen is released during their metabolism.
Also interesting is that by determining the isotope fractionation of
the chlorine in the perchlorate we may be able to determine whether
biologically mediated reactions were taking place:
Microbial Isotopic Fractionation of Perchlorate Chlorine.
Max L. Coleman,1* Magali Ader,1,2 Swades Chaudhuri,3 and John D.
Coates4
"Perchlorate contamination can be microbially respired to innocuous
chloride and thus can be treated effectively. However, monitoring a
bioremediative strategy is often difficult due to the complexities of
environmental samples. Here we demonstrate that microbial respiration
of perchlorate results in a significant fractionation (∼-15‰) of the
chlorine stable isotope composition of perchlorate. This can be used
to quantify the extent of biotic degradation and to separate biotic
from abiotic attenuation of this contaminant."
Appl Environ Microbiol. 2003 August; 69(8): 4997-5000.
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=169092
The TEGA instrument on Phoenix does have this capability to determine
isotope fractionations.
Bob Clark
dlzc
On Aug 12, 1:20 am, Robert Clark <rgregorycl...@yahoo.com> wrote:
> On Aug 11, 8:49 pm, "N:dlzcD:aol T:com \(dlzc\)" <dl...@cox.net>
> wrote:
>
> > Dear Robert Clark:
>
> > "Robert Clark" <rgregorycl...@yahoo.com> wrote in message
>
> >news:ee173208-e15e-43ea...@x41g2000hsb.googlegroups.com...
> > ...
>
> > > However, the perchlorate-metabolizing microbes release
> > > oxygen in reducing perchlorate to chlorate, then chlorite,
> > > then chloride.
>
> > They release oxygen from that *molecule*, not to the air.
> > They use the oxygen like other bacteria do... to "breathe".
>
> Some strains are anaerobic and therefore do not
> use oxygen.
Anaerobic bacteria are poisoned by free oxygen, but they all use
oxygen in specific internal processes.
> For these the oxygen is released during their
> metabolism.
You are thinking photosynthesis, where oxygen is released as a waste
product.
If you take certain bacteria from aerobic to anaerobic conditions,
they will start harvesting oxygen off of any stray molecule, starting
with sulfates, nitrates and ending with perchlorates, and bromates.
David A. Smith
Robert Clark
For some of these perchlorate reducers they do not use the oxygen
they generate:
BREATH OF LIFE.
Fated to Exhale
"Despite their diversity, these organisms share the same highly
specialized metabolism. They take in chlorate for respiration and use
certain forms of organic carbon as food. They convert the chlorate to
chlorite, another toxic compound, which they then break apart into
oxygen and chloride. They use the oxygen molecules to help process the
carbon, and they dump the chloride, a benign waste product.
In essence, says Coates, the bacteria "breathe in chlorate and breathe
out chloride.'
"Chlorate-using bacteria are now being used to treat
chlorate-contaminated wastes, such as rocket fuel wastes and wastes
from pulp and paper mills. But the patent applications Coates has
filed rest on another unusual characteristic of these microbes.'
"About three years ago, researchers in the Netherlands working with
the first known chlorate-using species discovered something
interesting. If they withheld carbon and chlorate, but supplied
chlorite, the bacteria still would break down the chlorite. But, since
the bacteria had no carbon to process, they gave off both oxygen and
chloride as byproducts."
...
"In lab experiments at SIUC, it took less than 10 seconds for a
population of chlorate-using bacteria to produce oxygen from
chlorite."
Bob Clark
Andrew Usher
> Well, the literature contradicts you. The solar wind and
> magnetosphere (which is rather well known) fixes N at
> about 40,000 tons/yr through electron impact. This is
> equal to 10 mb per billion years, a lot more than is currently
> in the air.
... or just not want to acknowledge that you're wrong?
Andrew Usher
N:dlzc D:aol T:com (dlzc)
It really helps if you leave the person's name in you are trying
to goad into responding.
> On Aug 7, 9:00 pm, Andrew Usher <k_over_hb...@yahoo.com> wrote:
<dlzc said>
>>> I don't see a non-biological way of making
>>> nitrate with this atmosphere.
>> Well, the literature contradicts you. The solar
>> wind and magnetosphere (which is rather well
>> known) fixes N at about 40,000 tons/yr through
>> electron impact. This is equal to 10 mb per
>> billion years, a lot more than is currently
>> in the air.
>
> ... or just not want to acknowledge that you're
> wrong?
Nitrate loses one nitrogen, and adds three oxygens. One electron
collision does not do all this.
It isn't about being wrong. It is about being civil. Goodbye.
David A. Smith
David Williams
-> > magnetosphere (which is rather well known) fixes N at
-> > about 40,000 tons/yr through electron impact. This is
-> > equal to 10 mb per billion years, a lot more than is currently
-> > in the air.
So? Nitrogen is cycled. It is "fixed" by various processes that turn
nitrogen gas into nitrates, ammonia, and other compounds, and then it
is turned back into nitrogen gas by biological processes, decomposition
and combustion of organic material, and so on. Every nitrogen atom has
probably been fixed and unfixed many times during the history of the
earth.
dow
Andrew Usher
wrote:
> It really helps if you leave the person's name in you are trying
> to goad into responding.
I wasn't trying to 'goad' anyone in particular.
> >> Well, the literature contradicts you. The solar
> >> wind and magnetosphere (which is rather well
> >> known) fixes N at about 40,000 tons/yr through
> >> electron impact. This is equal to 10 mb per
> >> billion years, a lot more than is currently
> >> in the air.
>
> > ... or just not want to acknowledge that you're
> > wrong?
>
> Nitrate loses one nitrogen, and adds three oxygens. One electron
> collision does not do all this.
As I explained nitric oxide, formed by the reactions triggered by
electron collisions, is likely to become nitrate or nitrite.
Andrew Usher
dlzc
> On Aug 12, 6:26 pm, "N:dlzcD:aol T:com \(dlzc\)" <dl...@cox.net>
> wrote:
>
> > It really helps if you leave the person's name in you
> > are trying to goad into responding.
>
> I wasn't trying to 'goad' anyone in particular.
Bull. You expect anyone that can respond to be "wrong" to start off
with.
> > >> Well, the literature contradicts you. The solar
> > >> wind and magnetosphere (which is rather well
> > >> known) fixes N at about 40,000 tons/yr through
> > >> electron impact. This is equal to 10 mb per
> > >> billion years, a lot more than is currently
> > >> in the air.
>
> > > ... or just not want to acknowledge that you're
> > > wrong?
>
> > Nitrate loses one nitrogen, and adds three oxygens.
> > One electron collision does not do all this.
>
> As I explained nitric oxide, formed by the reactions
> triggered by electron collisions, is likely to become
> nitrate or nitrite.
Who said anything about generating "nitric oxide" exclusively? In a
relatively oxygen rich environment, N2O, NO2, and N2O5 are nitrogen-
containing stable products. Water content of the gas stream controls
proportioning of each. We don't have oxygen rich, and we don't have
water vapor.
Bombarding nitrogen with an electron does not manifest oxygen
suddenly.
David A. Smith