how could a plant survive?

i dont think anyone mentioned how a plant would survive on mars, how would it adapt to live in these harsh enviroments. such as coating itself with a film of moisture.!NEWSROOM/spacestoryN1210GERMTOMARS.htm

For every one of those papers, there one that says different.

There are two many pseudoscientific essays that gloss over the truth.

Taking two of the points:

"Life developed on early Earth in extreme conditions similar to Mars."

Similar to Mars when? in what way? Where is the evidence?

"Some barren landscapes on Earth that are
similar to Mars harbor life today."

Name one barren landscape on Earth that is similar to Mars, complete with atmosphere and radiation levels?

Compared to Mars, Antarctica is a tropical paradise. To cite the ozone hole as producing
comparable radiation levels is nonsense. The ozone hole is relatively minimal in its effects during September to early November each year.

The low levels of nitrogen are quite rightly pointed out as detrimental to microbial growth. This is a major limiting factor, considering that life requires nitrogenous substances in order to survive.

"Early Earth was teaming with microbial life."

I think that should read _teeming_ unless they are referring to some sort of Gaian Symbiosis.

" type of photosynthetic bacteria called cyanobacteria (originally misnamed blue-green algae) put the first molecular oxygen in the atmosphere about 2 billion years ago"

That is by no means proven. We don't know what caused the first molecular oxygen. Cyanobacteria is a reasonable hypothesis, not an established fact.

The most logical conclusion based on research conducted to date is that Mars is sterile today.

It is possible that life may have developed on Mars, but that is not the most likely scenario based on the evidence we have seen to date.

Coming from a "Mars is sterile, skeptic"...

How do we know that the Labeled Release Experiment did not detect life in the Martian Soil? If this was done by "superoxides", can superoxides survive the seasonal deposition and vaporization of water ice. What about brines? Can "superoxides" survive in a brine? From what I have read so far, this is definitely not the case. If the Labeled Release experiment is repeated and it shows a nutrient preference for left or right-handed amino acids, does this imply that the soil is sterile? I don't think so. In fact, I don't know of any scientist (with the possible exception of Aldebaran and some others - :roll: ) who would think so!

What about life underground on Mars? How do we know that microbial life does not exist underground? How can we rule out this possibility?

The Earth's moon is supposedly a "sterile" body, and yet structures that resemble microbial fossils have been found in moon rocks.


How do we know that the Moon is completely and 100% sterile? Have any life detection experiments been performed on the Moon's polar ices? Underground?

And speaking of Gaia (especially from someone who is such a big proponent of astrobiology)... :roll:

"Salinity of the Sea

Lovelock says another example of Gaia in operation is the regulation of the saltiness of seawater. Seawater is about 3.4 percent salt by weight, and has probably been under 4 percent for as far back as we have data. If it ever rose to over 6 percent, all the life in the sea (except maybe for some archaebacteria) would be killed. Lovelock calculated that the entire salt content of the oceans is replaced every sixty million years by material carried from the continents in rivers and by material vented from below the ocean floor where it is spreading (10). Some other process must constantly remove the salt or else it would keep accumulating in seawater. This accumulation happens in seas where the removal process is not available, such as the Great Salt Lake and the Dead Sea.
The process Lovelock likes for preventing excess salt accumulation in the ocean is the evaporation of seawater in shallow lagoons and salt marshes. There seawater is evaporated for recycling, as rain, into fresh water. The salt precipitates out and is buried under layers of sediment. Thus, the shallow lagoons and salt marshes cleanse the oceans as our own kidneys remove impurities from our blood. Lagoons are created by coral reefs, huge biologically created structures. Lagoons gradually fill in, get shallower, and become salt marshes. So coral reefs, which create the necessary lagoons, have an essential, unexpected Gaian purpose (11)."


Is there a way to prove that "Gaia" is not at work on Mars by keeping something that has yet to be determined in some state of environmental balance?



From Reply 1:

"He cautions that more studies are needed, but the trend is clear: "Common bacteria may not be able to grow under Martian conditions," he said. "

What about Archae and the various families of extremophile organisms?


"What are the limits? Unkown.

A big question arises: Are the extremophiles very ancient forms of life, forms that inhabited the Earth (and presumably other planets) before the evolution of multicellular organisms? Are they a glimpse of what life was like at its very beginnings, before photosynthetic creatures began to pump oxygen into the atmosphere? Or are they microscopic hangers-on, pushed out of the richest, easiest environments by stronger competitors, clinging to marginal niches in the planetary ecosystem while their tougher rivals soak up the sunshine? Most biologists lean toward the first view: the extremophiles are among the earliest forms of life on Earth; they have always existed in extreme
environments -- those were the only environments that existed in our world's earliest days.

For more than half of Earth's 4.5-billion-year history those "extreme" environments were quite normal. It is only since photosynthetic bacteria, algae, and green plants transformed this planet's atmosphere to its present nitrogen/oxygen mix that "life as we know it" became possible here.

All the previous ideas about life on other worlds must be amended in light of the extremophiles. Deep below the surface of Mars, in the dim icy seas of Europa, wherever there may be water and heat energy there could be life. "


I will even venture to say that where there may be water and chemical energy, there could be life.

Also, what about nanobes?

"Nano Bacteria

Extremely small bacteria - also known as nanobacteria or nanobes - have only recently been discovered. They are a similar in size to viruses and while viruses are not truly living, nanobacteria do seem to be alive from the tests carried out on them. They are now the smallest living organism known. They puzzle many microbiologists though, because the cell structure seems just too small to fit in the components of a standard living cell. "


Are these just a bunch of fancy rocks that eat, excrete waste products, and reproduce?



Aldebaran says:

"The most logical conclusion based on research conducted to date is that Mars is sterile today. "

Well, I would like to counter that by saying the following:

The most logical conclusion based on research conducted to date is that we do not know if Mars is sterile or not.

And by the way, the results from the Viking life-detection experiments were not "negative". They were inconclusive.



"If life was completely absent from Mars, as the GCMS results suggested, these should have been the results from the biology experiments:

Experiments Response for sample Response for heat-sterilized control

GEX none none
LR none none
PR none none

Had terrestrial life been tested with the Viking biology instrument, the following results would have been expected:

Experiments Response for sample Response for heat-sterilized control

GEX oxygen or CO2 emitted none
LR labeled gas emitted none
PR carbon detected none

In highly simplified form, these were the actual results from Mars:

Experiments Response for sample Response for heat-sterilized control

GEX oxygen emitted oxygen emitted
LR labeled gas emitted none
PR carbon detected carbon detected"


These are not the results that one would expect from a "sterile" soil sample as shown above and are in fact inconclusive.

"But were the Viking probes looking for the wrong signs? The chemical reactions that drive biological activity are now known to be much more diverse than anyone suspected in Viking's day. It is now clear that reactions involving hydrogen, methane, sulphur or iron can sustain biological activity. Last year, Todd Stevens and James McKinley of the Pacific Northwest Laboratory in Richmond, Washington, discovered bacteria deep within basalt rock beneath the Columbia River that thrive only on hydrogen. The hydrogen is continually produced by chemical reactions between water and crushed basalt. An ecosystem like this would have been completely invisible to the Viking craft."

IMO, an ecosystem such as this would also produce weird results from the Viking life detection experiments.

Back to Reply 0. How could a plant survive? Maybe it can survive by forming symbiotic relationships with much hardier microorganisms.

"Earth microbes on the moon - Apollo 12 carried an inadvertent stowaway: a common bacteria, Streptococcus mitis. 50-100 organisms survived launch, space vacuum, 3 years of radiation exposure, deep-freeze at an average temperature of only 20 degrees above absolute zero, and no nutrient, water or energy source. [NASA Marshall Space Flight Center]"





Too much to respond to at once. I seem to have stirred up a hornet's nest. (It's a good feeling, and about time somebody did it)

The problem is when we feel so fervertly towards such a thing as life on Mars, we tend to take huge leaps of faith.

For example:

"What about life underground on Mars? How do we know that microbial life does not exist underground? How can we rule out this possibility?"

Well, we haven't ruled out any possibility. I didn't say that it was impossible, just highly unlikely. I said that the most logical conclusion based on evidence so far, is that there is no extant life on Mars. (Ok and no past life either). Why? Because to say otherwise would require evidence. There is no evidence.

As a counter argument, and trying to remain totally impartial in the argument. (Try saying this aloud - It's very therapeutic)

"What about the possibility that there are no suitable underground habitats for life? How can we rule out this possibility?"

What do we really know about underground conditions on Mars - temperatures, the presence of water etc? We don't include guesses, intelligent or otherwise. Do underground heat sources exist? Based on what? To what extent?

Superoxide is generated continuously on the surface of Mars based on simulated atmospheric conditions, with iron oxide mixes similar to those on Mars. Now the brine question - For the (what is it?) 1.6 hours per day, 60 sols per year that water is stable from an equilibrium point of view, if that water is actually present on the surface during any of that time, then it will tend to react with the superoxide to form hydrogen peroxide, another oxidizing agent.

As an analogy, let's take ether (say diethyl ether) on Earth. What happens if we pour it on the ground. Well it's a volatile solvent, and it will evaporate very quickly. Why does it evaporate? It should be liquid under most conditions on earth. It's below its boiling point, and theoretically it can exist in liquid form.

The same goes for Mars. At the low pressure of the Martian atmosphere, even in the narrow temperature range in which water can exist, it will tend to subliminate. Any free water or brine will evaporate, and absorb heat from the surrounding soil. (Ever hear about evaporative air conditioning?) The soil is generally about 60 degrees warmer than the atmosphere, so it makes sense that heat would be drawn from the soil. Any water would then produce its own microclimate which is cooler than the surrounding area. It will either freeze and evaporate, or evaporate totally.

Ok, what about Levin? Doesn't he talk about a limitation in evaporation due to the near saturation of the Martian atmosphere?

What do you think would happen to the Martian atmosphere during a regime where water is evaporating rapidly? Would it be (cool man) she's slowly buildin' up these nice calm theoretical layers that would prevent evaporation?

Well one obvious sign of extensive evaporation would be a thermal anomaly, another obvious sign would be extremely windy atmospheric conditions.

Windy conditions and equilibrium conditions do not compute.

What about all this ice in the Equatorial regions? Well all we know is that there is hydrogen. We have found some very stable hydrated minerals at both Gusev and Meridiani. Could this be your "Equatorial Ice" ?

Sorry to upset your reverie here. I'll concentrate on the other thread in the Open Forum.

Plants, Fungi, Lichens, Mosses, Liverworts...

How does anything survive ~ anywhere..?


No problem, Aldebaran; and your skepticism as a "Mars is sterile" proponent (i.e. "Mars has/had life skeptic") is quite understandable. So, here I am, as a "Mars is sterile" skeptic (past or present). The Mars Rover Blog forum seems to be sharply divided in this manner with polarized points of view on both sides of the debate.

I think what would convince me that Mars soil is sterile is to repeat the Labeled Release Experiment and verify that there is no nutrient preference for left or right handed amino acids. If this is the case, then this would greatly support the superoxide hypothesis. As for testing for the presence or absence of biological activity underground, that may occur well after our lifetimes. Testing and measuring for the present or past presence of life on an alien world such as Mars may well require a new set of criteria. And speaking of the possibility for the past presence of life...

The Mars Spherules as shown in Reply 0:

Have you, Aldebaran, or has anyone else been able to come up with an example of a natural geologic formation that has an Asymmetric Logistic Peak size distribution profile (on an arithmetic scale) like the one shown here?

So far, the only thing that matches (same type of distribution) that I am aware of is RPage's collection of fossilized Crinoid stems:

Jon Clarke tried to come up with an example with the Weipa Pisoliths, but they turned out to be either lognormal or lognormal with a shorter tail when Henry and I converted the %wt graphs from there original equal spaced logarithmic axis to an equal spaced arithmetic axis (see pages 29 and 30 in the "Go Measure" thread).


Now, about those "windy conditions" in a near vacuum (6 to 10 millibars)...

I seem to remember that "windy" conditions (at least on Earth) do signify a change in barometric pressure:

I would expect a couple millibars change in atmospheric pressure on Mars due to windy conditions.

Earth has wind, too, and it also has numerous "Gaian" processes at work as well. Mars is still a complete unknown in this regard.



This is the one for Endurance crater (Ref. Reply 10):



On the subject of superoxides (and yes, this is from your favorite author, Aldebaran - :roll: ):

"Each of the several approaches discussed herein to determine the oxidative state of Mars has supplied its respective proof of the absence of a highly oxidizing material on the surface of Mars. Yet, these proofs continue to be ignored. A variety of papers has appeared over the past several years speculating about how future life-seeking missions to Mars should avoid sampling where the oxidant is presumed to be. Elaborate robotic drilling machines have been proposed to get samples from beyond the "oxidant zone." The ill-fated Mars Volatiles and Climate Surveyor (MVACS) carried an experiment to detect the oxidant(s), but carried no life detection test. The forthcoming Beagle II Mars lander, slated for 2003, will also carry an oxidant detection experiment. However, like the MVACS, it will not carry a life detection experiment. Nor, according to published plans of NASA, will any of the biennial missions planned for Mars throughout this decade carry life detection experiments.

It thus appears that the paradigm of a Mars sterilized by a highly oxidizing surface is too embedded in our scientific fabric to be set aside even by demonstrated proofs. As John Kennedy said, "the great enemy of truth is often not the lie deliberate, contrived and dishonest but the myth persistent, persuasive and unrealistic." Returning to Table 1, it should be added that the other explanations proposed in attempts to reconcile the GCMS and LR results have been found to be futile also, leading to that paper’s claim that the Viking LR experiment detected living microorganisms in the soil of Mars.[32]".


It's unfortunate that the Beagle II Mars Lander was not able to perform the superoxide experiments.



Back to Reply 0. If future experiments show that there are no superoxides in the Martian soil, then that would definitely present a much friendlier environment for some kind of strange "Mars plant" to survive.



IMO, the claim of "superoxides" in the Martian soil is a "huge leap of faith" that currently has no experimental data to back it up.

More from Reply 12 (superoxides):

"The next direct exploration for hydrogen peroxide in the Martian atmosphere occurred over the decade from the middle 80’s to the middle 90’s. Using Earth-based high-resolution spectroscopy through the Kitt Peak National Observatory 4-m telescope, Mars was examined[18] for H2O2, H2CO, HCl, CH4, and HDO. Under the best opportunity occurring during that period no spectrographic feature for H2O2 was found. This examination established an upper limit of 30 ppb for that oxidant throughout the atmospheric column of Mars, approximately one-half an order of magnitude below that established by Mariner 9.

Compelling direct evidence against hydrogen peroxide, or any highly oxidizing substance in the surface material of Mars, was provided by Viking in 1976, but only just revealed herein. One of the principal stated objectives of the Viking Magnetic Properties experiment[19] was to determine the oxidative state of the surface of Mars. It was stated in a pre-mission publication[20] that, ". . . on the basis of how much, if any, material is adhering to the magnet, we will try to draw some very general conclusions pertaining to the oxidation state of the surface. Mars is supposed to be a red planet and it has often been suggested that this is because there is lots of the mineral hematite (oxidized iron) on the surface, which makes rocks on Earth red, but this is a form of iron which is not at all magnetic. If there has been indeed very pervasive oxidation on the surface of Mars, I would not expect to pick up anything magnetic. On the other hand if there is a lot of material adhering to the magnet, it would certainly say that whatever the surface processes are on Mars, they are not innately highly oxidizing."

"Under the discussion section of the paper[27], the statement is made, "Furthermore, the soil in general is not only highly oxidized, but also strongly oxidizing." This sentence is not supported anywhere in the paper. Essentially the same statements are made in another paper[28] (by the same senior author and including all of his co-authors), "The soil in general is not only oxidized but is also strongly oxidizing, as evidenced by the effect on organic nutrients to which the soil was exposed in the Viking biology experiments (11)." Another report[29] on the Pathfinder Magnetic Properties experiment makes no mention of the oxidant state of the soil. Thus, the only "evidence" presented in the reports of the magnetic properties experiments on Viking and Pathfinder regarding the state of oxidation of the Martian soil, originally cast as a principle goal of the experiment, is a citation referencing the Viking biology data. Nor, in any paper, is there any disclaimer made concerning the pre-Mission criteria for determining the oxidizing state of the Martian surface material: any magnetic material picked up by the magnets meant that the Martian soil could not be highly oxidizing. If the Viking and Pathfinder magnetic properties experiments, indeed, proved that the surface was not highly oxidizing, this major finding, particularly major in light of the conflicts that have raged in the literature for the past 25 years, should be the subject of a major paper. On the other hand, if the pre-Viking statement describing and justifying the experiment has been shown to be erroneous, this fact should have been published in the reports on the magnetic properties experiments. As of this moment, it would seem that one is perfectly justified, on the basis of the experimental results of the magnetic properties experiments on Viking and Pathfinder, to conclude that they produced proof that the surface of Mars is not highly oxidizing. Based on the infrared reflectance spectra of the dark regions of Mars, it has been suggested[30] that the characteristic feature of Fe2+ indicates the presence of the ferrous mineral pyroxene. This conclusion is supported in a later paper[31] on the Pathfinder experiments that also says "the soils . . . may . . . contain a greater abundance of a less heavily oxidized component, like ferrous–bearing pyroxene (emphasis supplied)." Were the soil highly oxidizing, all ferrous iron would have been converted to ferric or more oxidized forms."



" no spectrographic feature for H2O2 was found"

Doesn't look good for liquid water then.

I'll spend more time on this on the weekend. I hate these days that are sandwiched between public holidays, and I normally take time off.

I think you may be right on that point, Aldebaran, but I'm not so sure about brines with the corresponding decreases in the freezing point, elevation in the boiling point, and lowering of the pressure Triple Point (solid,liquid,vapor) from 6.1 millibars to about 2-3 millibars. Anyway, I do apologize if I have made you (or make you) feel uncomfortable in any way about this topic (possibility of past/present life on Mars). Have a safe and Happy New Year!



Anyway, on the subject of brines, I think both you and RPage have made some very good points in the following thread from the Mars Geology Forum:



"Anyway, I do apologize if I have made you (or make you) feel uncomfortable in any way about this topic (possibility of past/present life on Mars)."

It's a subject close to my heart. I'm not uncomfortable discussing it, just time-limited. The problem I have is that people get carried away to cloud cuckoo land.
I'm not saying that I include you in that broad statement.

It's always good to drag them down to Earth again. If we want to know the truth we must always play devil's advocate. Look at the opposite side of the argument. If you win easily from the opposite side, there is something fundamentally wrong with your model.

Work on teh basis that all theories are lies. Our task is to shoot them down in flames. Whatever is flameproof and survives must be the truth.

If the surface is highly oxidizing, why Grey hematite, and only a little red, down at the bottom of endurance?
Why are there particles sticking to the magnet?