This seems to be the case. But just imagine what these words mean! Garden soil? Well, I don't know where you live on this Earth, but I live in an area that at -30C the 'garden-soil' is hard as a rock, until it thaws in, say around mid-March or so. The ground freezes to a depth of about 6' every year and in some cases has gone to 7' and lower enough to crack buried water mains.
So haven't you noticed that here at the Phoenix site and everywhere else I guess on Mars that the soil is 'MOVEABLE' and parts itself as if the temps were in the mid 20's C.
What's up with this! It certainly can't be from the PH or alkalinity or salts mixed in.
Any thoughts on this before we are told the soil conditions have some other goodie we can't identify?
"It is the type of soil you would probably have in your back yard, you know, alkaline. You might be able to grow asparagus in it really well. ... It is very exciting for us."
This is by far the biggest turnaround in the official view of Mars life prospects for decades, and should not be dismissed lightly. NASA were so keen to treat the Viking results as a "false positive" that they had to hypothesize a mysterious "oxidising agent" in the soil which was inimical to life but which mimicked its effects. Phoenix is not findung any mysterious oxidisers, just salts and nutrients in the sort of PH that asparagus would thrive in. Maybe a bit lacking in humus, but that's something yet to be established.
DX, of course it's cold. It's the far north. Even on Earth the corresponding region, the tundra, is extremely cold. But the asparagus, when it is eventually grown. will be in heated greenhouses so the ambient temperatures are irrelevant. And there are places on Mars where the temperature occasionally reaches 20 degrees c. Even at the Phoenix location the temperatures can get close to 0 degrees c, so it should be possible for liquid brines to exist.
Only the very top layers of soil are moveable. I'd say that beneath a thin layer of dusty soil there's just solid ice, because Phoenix is sitting on a frozen lake. That's why the region's so flat. The top level of soil is moveable because the moisture in it readily sublimates, especially when it has been placed in a scoop and raised above ground level. Just the slightest wind is enough to dry the upper levels of soil out.
point about drying by wind, is new to me and interesting too.
Key fact is the that -30C max temperature mentioned for the Phoenix site is air temperature. The actual ground temperature might be -10C max or higher.
NASA/UofA are saying everything, so perhaps 1 thing may eventually be correct. Nothing like throwing a handful of darts at a balloon, 1 or 2 will hit. But I know what you are saying, and I too have discussed the briny soil years ago on the Rovers side of this Blog.
Soil or sand from deserts too are thrown out to us, but they did not mention sandy-loam, one of the best growing media there is!
As es pointed out in 3, I also like that idea. The wind does blow, there is enough Phoenix photos to show the weight moving in the wind at the Mars weather station on board as an everyday occurrence. Would it be a cold blow or warm sunlit blow, or a gentle summer breeze in a clear sunlit sky? And just what elements blow? What's the Mars wind made of? Here it is.
copied from Wikipedia,
'The atmosphere of Mars is relatively thin, and the atmospheric pressure on the surface varies from around 30 Pa (0.03 kPa) on Olympus Mons's peak to over 1155 Pa (1.155 kPa) in the depths of Hellas Planitia, with a mean surface level pressure of 600 Pa (0.6 kPa), compared to Earth's 101.3 kPa. However, the scale height of the atmosphere is about 11 km, somewhat higher than Earth's 6 km. The atmosphere on Mars consists of 95% carbon dioxide, 3% nitrogen, 1.6% argon, and contains traces of oxygen, water, and methane. The atmosphere is quite dusty, giving the Martian sky a tawny color when seen from the surface; data from the Mars Exploration Rovers indicates the suspended dust particles are roughly 1.5 micrometres across.'
Reply to Robert Clark:
I believe I already mentioned that you need to alter the way you present your information. In order for this forum to have any credibility, whenever you mentioned such an important fact - you need to have a reference, or at least state a solid basis for your estimation.
Paul, et al,
From your first link at the Phoenix site, the link to the released associated images is here for others to access those directly. My pages open like snails so the link may help others as well. Intrigue in the soil report as the particles from the OM photos show items types from the Gusev Abyss area, both MER rover locations for the other 'pepper' stemmed shape, and the micro-spheroid with the surrounding 'apron' shaped periphery, and all those linear curved items which are so numerous they are piled onto one another in one of the photo particle clumps. It was as though we were looking at microscope samples of the two rover lander locations, not a new zone of Mars. Can these items be a planet-wide pattern of minerals or other items which bulk up the chemistry differences of the regions? Would we find the general chemistry of the north region to be this neutral to alkaline in pH?
I hope this is a deeper chemistry of stable local type mix, and not a wind blown topsoil of just a few inches. The winds have been at work long enough to have mixed kilometers of depositioned material. Perhaps this is the Mars of the north, and the items are planet-wide in dispersal. If the items shapes are indicative of the local geology activity, and a history only locally, it would appear we have a differing chemistry from a common set of source materials. A great story is being unfolded, only to bring more questions than answers, as usual, on Mars.
A link to a couple 2x views of the soil RAC images which are in the News releases. These are hopefully able to allow persons to view aspects of the clumps which would not be seen at the smaller size. These were altered by brightening 10 points, contrast reduced 10 points, and the gamma increased 10 points. The shadows are viewable, the darker clumps within the reddish large clumps are separated from the shadows, and the linear and radiating patterns of the soil clumps are more resolved into distinct patterned shapes. Hope these poor 200% images do some value for some of you. I could not distinguish the darker clumped parts until I made these changes. A JPG and then a PNG of the same image number lg_7851 from the image collection at the link I gave in this entry. Seek the originals for proper full viewing of all aspects of the information. These are just aids in some detailing. Warning. When viewing the larger file image from Phoenix, the opened page is one way only, no 'back' button process. Open only in a new window if you try that selection. My altered images should be a two-way street for your use.
The images will adapt to your monitor size as full frame, and you must mouseclick them to view at full size of 200%.
I want to thank you for the linked report, more good news from the Phoenix lander.
I find it odd that the darker clumped material didn't seem to make it into the OM images. That may be less altered material, tougher, or more cohesive. If so, why do we see it, with none in the photos after the scooping? It can't be shadow, and it can't be any illusion. The two types are within the images. Perhaps a non-glassy reflectance angle which is narrow? Any ideas? Oriented materials are very common on Earth, in clumps or sections of clumps, but this is a damaged, enlarged view, also. I was thinking of the very dark materials of the Abyss as a possible source type similarity, altered perhaps, locally.
There is a Q-Time video in this NASA link. Run it if you wish.
Just wondering what a human finger in this soil would feel like, besides the consistency of dog-crap. I know that's not scientific statement, but perhaps it is. We do use our scenes to discover the world around us, do we not?
I couldn't resist this one.
Just got into my freezer and grabbed the 'Italian' bread crumbs to sprinkle some into my hamburger mix as usual. Well, we all know the freezer is the place to keep things frozen, and the bread crumbs came tumbling out in a neat pour, just as if it was a liquid. The crumbs were cold of course and so was the container, but the pour was not clumped or packable as damp snow would be. Air is certainly between each of the crumbs to keep them separate.
Now, I'm not saying that Martian soil is like my Italian bread crumbs but the action seems to look the same and took the same appearance. Its freezing cold material, bright and sunny day for the pour and it heaped like the Phoenix soil heaps beside the digs!!!
As I said earlier there must be some substance in the soil acting as a separator of sorts yet keeps them binded together.
Any thoughts out there?
BTW>>>the burgers are for the BBQ 4th of July holiday and Canada Day of July 1 here in North America.
Happy 4th my American friends.
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What I am curious about is whether there are nitates in the Martian soil. On Earth, these are needed as fertilizer. Life as we know it uses proteins, which contain nitrogen. So far, I have not seen any detection of nitrogen on Mars, other than the small quantity (3%) in the thin atmosphere. This may be a limiting factor for life on Mars.
Unfortunately, the perchlorate would swamp any signature of nitrate from the perchlorate/nitrate sensor (since perchlorate has a much stronger signature). But maybe TEGA might have detected some oxides of nitrogen?
How could one talk about habitability from an earth perspective without identifying nitrates?
I suppose they can't tell whether WCL has seen nitrates or not because the signal would be masked by the perchlorate abundance.
Hopefully, we will get a clearer picture on Monday, especially if the newsmen ask good questions.
What I'm really saying is that I do'nt buy the whole phoenix garden soil- habitability-perchlorate story.
Dr Smith is a very intelligent man leading a uniquely placed international team. When he talks about habitability and likens the phoenix soil to a backyard garden soil I expect that he knows something about garden soils and that he has some information that the phoenix soil, in addition to pH and some mineral content, has some of the main characteristics of an earth garden soil. Nitrogen content is a most important aspect of such a soil.
I think that the perchlorate escalation was somewhat of a red herring and that in the years ahead we will most likely return to the habitability question.
I agree with you that nitrates would be masked by perchlorate abundance but have'nt they been sampling from different levels of the soil and different sites? have perchlorates been abundant at every site? have they exhausted all the sites that could have been sampled for soil constituents? could some tweaking of the detectors give a better idea of if nitrogen was present in the soil. As far as I know Nitrogen is present in the atmosphere? How could it be present in the atmosphere and not show up in the soil? Perhaps there are no nitrogen fixing bacteria but other processes could fix nitrogen, I think.
COuld it be that the wrong instruments were taken to the phoenix site to do the required job?
And what about those pesky super oxidants that supposedly bedevilled the Viking LR experiments, the theoretical superoxides? Have they shown up so far? I have'nt heard anyone claim so far that the perchlorates could be the culprits in that effect.
Tomorrow there will be a NASA press conference that will hopefully give us some snippets of information on the results of the phoenix investigations as the mission winds down. At the beginning of the mission I had ventured to predict that this mission would provide new facts that would put us much closer to determining that current life exists at or near the surface of Mars. However, the information released so far suggests that this hope might be somewhat optimistic but that there is probably an incremental swing towards the pro-life camp.
That got me wondering as to what it would really mean if Mar's surface were indeed currently sterile and thereby recognizing that such an eventuality would totally disrupt the scientific consensus on the beginnings of life on Earth and our portion of the Universe; Panspermia; and the search for life outside Earth; etc.
Just consider that Mars has many characteristics that are the nearest thing to Earth's in this solar system; The geology looks quite similar; the Phoenix team leader initially declared that the soil they first tested was similar to garden soil on earth; many laboratory experiments have determined that a range of microorganisms can survive and perhaps even thrive under simulated Martian conditions; the disputed viking LR results suggested the possibility of organisms being present in the soil there; etc; etc.
With such a similarity to Earth and given the current scientific hypotheses on the origin of life on Earth there should be no question of extant microbial life (at least) existing on Mars.
But the competing hypothesis is holding the sway. It would appear that most scientists (based on the ones who comment on this forum and UMSF) consider that there is no such thing as extant life on Mars. If that turns out to be true, it seems to me that we would have to rethink our hypotheses on the origins of life on Earth.
Why should life have taken hold on earth and not on its sister planet? Was life there aeons ago but got wiped out by a catastrophe? If so, has'nt the experience of catastrophes on Earth taught us that there are always some survivors? Shouldn't there be some survivors from the putative martian catastrophe or catastrophies, especially in protected areas and perhaps entombed as spores in dust and in protected environments? Should'nt panspermia have continued to seed Mars surface with spores, some of which would have taken root over the millenia, or whatever other timeframe you choose, after the catastrophe?
Of course one hypothesis that would still be left standing is the biblical creation of a unique Earth. Would a sterile Mars be a point in favour of biblical creation? Or would it have no relationship whatsoever to a biblical creation?
AS I've made clear in several posts here over the past 4 or so years, my position is that there are living microbes in that martian soil, well adapted to the environment on Mars that has fortuitously provided conditions where water can exist for certain periods on or near the surface and where various options are provided for metabolic activity of microbes. I think that it is unlikely that Phoenix will confirm this but there will be future better equipped missions that I still think will confirm native biology on Mars.
Non-biological sources of fixed nitrogen are lightning and combustion, but neither seems likely on Mars. Perhaps volcanism and meteorite impacts might fix nitogen over time. Clearly, there were sources of fixed nitrogen on early Earth, so there may be pre-biological nitrogen fixation mechanisms that no longer operate once biology become widespread.
Ammonium compounds are an alternative to nitrates as fertilizer. But I haven't seen any reference to ammonium either in the Phoenix results so far. It seems unlikely that the perchlorate salts are ammonium perchlorate since, according to wikipedia, "Mild heating results in chlorine, nitrogen, oxygen and water," and it doesn't seem that chlorine was detected by TEGA. (But the chlorine emission could be suppressed by a chlorine scavenger such as potassium nitrate or lithium carbonate.)
re. fixing NItrogen, I know this is very controversial but the Electric Universe proponents posit that dust devils could have some electrical discharge component and there are some images from Spirit that support this to some extent.
No mention of nitrogen at the press conference, and no one asked about it. Given the importance of nitrogen to habitability on Earth, why is every one ignoring it?