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This is an old revision of this page, as edited by Robertinventor (talk | contribs) at 15:30, 5 January 2015 (→OR in Habitability Assessment). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

This article contains a translation of Voda na Marsu from cs.wikipedia. Translated from Czech Misplaced Pages

	Astronomy B‑class High‑importance
This article is within the scope of WikiProject Astronomy, which collaborates on articles related to Astronomy on Misplaced Pages.AstronomyWikipedia:WikiProject AstronomyTemplate:WikiProject AstronomyAstronomy B This article has been rated as B-class on Misplaced Pages's content assessment scale. High This article has been rated as High-importance on the project's importance scale.

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Entire talk page with many open sections has just been archived by BatteryIncluded

Just want to point out to other editors that this has happened. I believe he did this in response to a recent comment of mine in the sction where I mention an idea for a new article on the habitability of present day Mars, the subject of numerous published papers over the last six years and a major conference in February of this year.

I commented that although I had received a response from another editor suggesting I do it as clearly notable, I don't feel able to do it right now as I am pretty sure it would be immediately nominated for deletion.

He archived the page by the next day after I posted that comment. I assume good faith and don't accuse him of vandalism or anything of that sort, just suspect there may be some element of bias involved in his decision that this entire talk page needs to be archived at this moment of time. Robert Walker (talk) 16:26, 26 June 2013 (UTC)

You said your goodbyes in your last post. Besides we care little on what are your plans for your blog. THIS IS NOT A FORUM. BI

Recommendation, new article on the Present-Day Habitability of Mars

I highly recommend that Misplaced Pages should have an article on this subject.

This is the conference on the subject "The Present-Day Habitability of Mars 2013".

Paige is planning to create a new journal solely devoted to this subject. See UCLA holds Mars habitability conference:

At the end of the conference, Paige said he intends to publish a special journal focusing on the present-day habitability of Mars and hopes to reconvene the conference within the next five years

This is the old section from this page on habitability of the Mars surface User:Robertinventor/possibility of Mars having enough water to support life.

There are many papers on it every year by researchers in the US, UK, and Germany, and including scientists from JPL, DLR in Germany, and the NASA Ames Research Center. It has been a major subject in the literature since 2008 and undoubtedly passes WP:NOTABLE.

If another editor feels as strongly as I do that creation of this new page is a good idea, please let me know via my talk page. With two main editors involved in its creation, I feel it would easily survive AfD and be well protected from edit warring. Robert Walker (talk) 06:42, 27 June 2013 (UTC)

There is no need for a separate article just for you to spread your spam. Already existing articles suffice to discuss habitability. The above disingenuous attempt to recruit naïve meat puppets not yet aware of your project to act out your doomsday fantasies on Misplaced Pages will not work. Warren Platts (talk) 14:47, 27 June 2013 (UTC)

No need to be so nasty, personal attacks do not help make a point. @OP Life on Mars is a closely related article and it already has some content on habitability, if you or anyone else can add more content relating to this, I would suggest expanding that section first rather than starting an entirely new article. If there is no question of notability it could be split of at some later date anyway. Reatlas (talk) 05:38, 28 June 2013 (UTC)

I second all of Reatlas' comments here. DanHobley (talk) 15:47, 28 June 2013 (UTC)

Sadly I can't do that. One of the editors of that page also considers me to be a fanatic and deleted a fair bit of material on present day habitability of Mars here and on that page by various contributors (not just me, there was a long section on it already and I just added a few sentences to it). As I understand it, he considers that present day life on Mars is impossible and that therefore the material in the "The Present-Day Habitability of Mars 2013" conference and other recent work suggesting possibilities of habitability of Mars should be ignored, when I tried to mention them in the talk pages.

But there was nothing fringe or fanatical about this research. It was a main stream conference. These scientists are not saying there is evidence for present day life on Mars. Not even that there are habitats on Mars, as that's not yet confirmed. They just presented various lines of evidence suggesting possibilities for present day habitats on Mars. But that was enough to make it too controversial to be included here, so I was told. I've given up on this for now. Robert Walker (talk) 01:42, 25 January 2014 (UTC)

Just to say, I gave it a go, not editing the article itself as I knew any edits would be reverted immediately, but added a suggestion to the talk page as a new section just saying that since 2008 ionizing radiation is no longer considered an issue for life on the surface of Mars, and mentioning a few other things + corrections. All of this is totally mainstream now and non controversial.

The editor concerned first posted saying that everything I said was nonsense, no discussion or mention of anything I said, just a string of insults. Then after I replied to that, he deleted the whole section from the talk page - see: this diff.

I've restored that section on the talk page and asked him not to delete it again, will see what happens. Whether or not, is seems, right now anyway, unlikely that he will permit any editing of the page itself to include this material from the 2013 Habitability of Present Day Mars conference. Robert Walker (talk) 16:49, 27 January 2014 (UTC)

Research published in January 2014 of data collected by the RAD instrument, revealed that the actual absorbed dose measured is 76 mGy/year at the surface, and that "ionizing radiation strongly influences chemical compositions and structures, especially for water, salts, and redox-sensitive components such as organic matter." Regardless of the source of Martian organic matter (meteoritic, geological, or biological), its carbon bonds are susceptible to breaking and reconfiguration with surrounding elements by ionizing charged particle radiation. The report concludes that the in situ "surface measurements —and subsurface estimates— constrain the preservation window for Martian organic matter following exhumation and exposure to ionizing radiation in the top few meters of the Martian surface." Paper: Hassler, Donald M. (24 January 2014). "Mars' Surface Radiation Environment Measured with the Mars ScienceLaboratory's Curiosity Rover" (PDF). Science. 343 (6169). doi:10.1126/science.1244797. Retrieved 2014-01-27. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help) So, Robert Walker, kindly limit your denialist-pseudo-BS to your own blog. Sincerely, --BatteryIncluded (talk) 19:00, 27 January 2014 (UTC)

That's for past life, not present day life. There is almost no chance of present day life where Curiosity is, as the ground is dry not just on the surface but probably for hundreds of meters below the surface. Evidence of past life would also be destroyed, and they suspect that this area of organics must have been uncovered relatively recently - where recently means geologically recently like in the last few hundred thousand or millions of years - because if it was exposed for billions of years there would be no organics left or nowhere near the amounts they measured. That's what that quote is about Robert Walker (talk) 19:25, 27 January 2014 (UTC)

Another WP:CHEESE entry from the troll. What's new? BatteryIncluded (talk) 23:18, 27 January 2014 (UTC)

More on this, just wanted to update on the figures I gave for how long ago those deposits were uncovered. New results just in show that the organics uncovered by Curiosity were probably uncovered between 30 million and 110 million years ago. See New Results Send Mars Rover on a Quest for Ancient Life Robert Walker (talk) 15:19, 29 January 2014 (UTC)

Nonsensical sentence in lead

"More than five million square kilometers of ice has been identified on the surface of modern Mars, which is enough to cover the whole planet to a depth of 35 meters."

That would be an impossible calculation, since it would be attempting to derive a volume from an area. --El Ingles (talk) 23:30, 27 September 2013 (UTC)

Good catch. The units were entered incorrectly. Original source (Christensen, 2006) gives >5 million cubic km of ice. This should be corrected. Schaffman (talk) 11:02, 6 October 2013 (UTC)

Article does not mention water in hydated minerals and as hydroxyl

Water on Mars is also present as hydroxyl, in water of hydration, and in the form of other bound water in rocks and minerals. I think this water reservoir should at least be discussed briefly because it probably makes up a significant portion of Mars' total water inventory. Do others here agree? Schaffman (talk) 19:47, 6 October 2013 (UTC)

Sure! BatteryIncluded (talk) 22:35, 6 October 2013 (UTC)

Yup. DanHobley (talk) 14:53, 8 October 2013 (UTC)

Notes on Recent Activity on Article

You all will notice I've been dabbling with this article, making some minor editing changes here and there, mainly in the intro section. Most of the tinkering has been with the references. IMO, there are too many. Some are inappropriately located and redundant. Also, I think that when citing books, page (or at least chapter) numbers should be given. For example, Mike Carr's Surface of Mars is a great reference, but covers a lot of water-related topics by chapter. To just cite the book as a reference doesn't help much. I also have mixed feeling about the abundant use of tertiary references (press releases, newspaper articles, etc.). I prefer using primary or good secondary references exclusively, but realize that these are not always accessible to general reader. So I don't know.

In short, I think the references need to be culled and better arranged. Not a sexy task, I know, but necessary to allow easier editing to improve the article. Any thoughts? Schaffman (talk) 08:27, 13 October 2013 (UTC)

BTW: Carr has written a whole book with the same title as this article. Though a little dated now, it's still a good resource. I've added it to the bibliography and recommended reading list. Schaffman (talk) 09:31, 13 October 2013 (UTC)

Hello. Yes the references need to be culled. Some history: up to a few months ago, this article was extremely long with multiple redundant sections and references of all qualities. I performed a major cleanup and reformatted the article in June 16, 2013. I made an effort to keep all references for future cleanup (see my notes under "Reorganization and re-write".) User:DanHobley did considerable work following mine but a lot of redundant/outdated references remain. Please feel free to continue your high-quality edits, as I for one, appreciate the input from experts like you and Dan Hobley. Cheers, BatteryIncluded (talk) 14:08, 13 October 2013 (UTC)

Thanks much for your comments. I know how these articles can get cluttered over time and how much thankless work is involved cleaning them up. Seems a never-ending task. Glad you and others are out there interested in this subject. BTW: Dan's the real expert. I'm just a dabbler, but thanks anyway :) Cheers. Schaffman (talk) 17:02, 13 October 2013 (UTC)

I have a copy of The Surface of Mars sitting a few feet from me right now! Most of the refs to the Carr are mine, so I can probably (slowly?) add some more detail. Pages probably shouldn't be too terrible to put in. And thanks again for all the effort on this article guys - it's just so so much better than it was before BI's epic efforts in June. I feel like we could get this thing really very nice if we put in just a bit more effort, and it is a fairly important topic for WP.

Agree we should probably try to strip back refs too, though to some extent a big list is inevitable for a big topic like this. I also would agree we can remove some of the tertiary stuff, though I've also run into editors elsewhere in the science articles who actively prefer them because of access. I guess I also am unsure. Is there recommended policy we can follow here? DanHobley (talk) 18:05, 13 October 2013 (UTC)

Thanks Dan. And ditto on you and BI's great efforts here. I hadn't seen this article until recently. I'm sure it is infinitely better than before with your guys worked on it. I think the policy is to prefer primary and secondary references...but I'm not totally sure either. Hope the Surface of Mars comment did not come across as disparaging. Not my intent at all. I just may have a different preference than others. Best regards, as always. Schaffman (talk) 19:55, 13 October 2013 (UTC)

Oh, and I also know how these references can multiply. I added a few myself...D'oh. Schaffman (talk) 20:07, 13 October 2013 (UTC)

In a science article like this one, most primary references will be from papers published in peer-reviewed journals, which lately, are accessible for a fee. Misplaced Pages favors free access sources. I think a balance can be reached by quoting the papers' abstract, books, and deleting redundant references from news media. We could also delete older (outdated) references. Cheers, BatteryIncluded (talk) 14:14, 14 October 2013 (UTC)

I spent some time reviewed all the references for their reliability. They all are of high quality and found nothing outdated that grants deletion. Of particular interest is the Habitability section, which displays long strings of references. Mea culpa; It developed from an edit war between me and a fanatical user convinced of a impending and fatal Martian microbe invasion. I could trim them but in my experience with that user, he might get a second wind, and his contradicting 10 peer-reviewedpapers is harder than one. Cheers, BatteryIncluded (talk) 15:48, 19 October 2013 (UTC)

BI, the OR part of that section is when you say that life on the surface is likely dormant. Many well known scientists such as Nilton Remmo have become optimistic for prospects of life on the surface of Mars very recently, over the last few years (from 2008 onwards) as a result of models, experiments replicating Mars conditions on the Earth, and observations that all point towards the possibility of liquid water that forms on the surface of Mars occasionally. Just a few droplets of cold salty water on ice salt interfaces, or cold brine flows just a mm or so thick, but that's enough for microbial life. As Nilton Remmo said about his team's experiments that created droplets of water in Mars analogue conditions, a tiny droplet of water is like a swimming pool for a microbe.

Life that revives from time to tine - if radioresistant, can repair all DNA damage for up to several hundred thousand years of dormancy in a few hours. The level of cosmic radiation on the surface of Mars is similar to the interior of the ISS and does not prevent life if it revives occasionally.

For more on this, see User:Robertinventor/Present_day_habitability_of_Mars_dispute, which includes some of the more notable material I posted to the Life on Mars talk page about this over the last year or so. I know that you keep hiding this material from the talk page as forum / soapbox / spam - but it isn't, it is mainstream science. Do take a look at it again and read it more carefully!

They are talking here about sparse populations similar to the microbes that are able to survive in the hyperarid core of the Atacama desert - even with an extensive search it is hard to find it, but if you look, for instance in the micropores of certain salt pillars you find small populations of a few microbes, slowly metabolizing. Similarly in the Antarctic dry valleys - look just below the surface of some rocks, and if you are lucky, you find patches of microbes which may have lifetimes measured in thousands of years, they metabolize so slowly. If these postulated habitats on Mars exist, then Mars life may be like that.

I am not a troll and have always edited wikipedia according to the guidelines and in good faith edits, followed BRD, and never been a disruptive editor. Have said a bit more about this below, collapsed it as most readers of this talk page surely won't be interested in the details:

Robert Walker (talk) 18:41, 3 January 2015 (UTC)

Proposed new wording for Third Paragraph in Intro

Guys, I planned to rework the third paragraph beginning "There are a number of direct and indirect proofs of water presence..." But wanted to get your take first. The new version would read:

Many lines of evidence indicate that water is abundant on Mars and has played a significant role in the planet’s geologic history. The present-day inventory of water on Mars can be estimated from spacecraft imagery, remote sensing techniques (spectroscopic measurements, radar, etc.), in situ investigations from landers and rovers, analysis of Martian meteorites, and theoretical models. Geologic evidence of past water includes enormous outflow channels carved by floods; ancient river valley networks, deltas, and lake beds; and the detection of rocks and minerals on the surface that could only have formed in liquid water. Numerous geomorphic features suggest the presence of ground ice {permafrost) and the movement of ice in glaciers, both past and present. Gullies and slope lineae along cliffs and crater walls indicate that flowing water continues to shape the surface of Mars, although to a far lesser degree than in the ancient past.

The difficulty is what to do with the existing references, most of which are very good. That was the dilemma that prompted my original comment about the references. Thanks for any input. Schaffman (talk) 22:56, 13 October 2013 (UTC)

Looks good. BatteryIncluded (talk) 14:05, 14 October 2013 (UTC)

Thanks, BI. And thanks for the beer too ;-) Schaffman (talk) 14:37, 14 October 2013 (UTC)

Good stuff. Only thing is you might want to hedge a bit more in the final sentence. Modern water is still pretty controversial, so you probably want to go for "suggest" rather than "indicate". But the rest is ideal. For the refs, I say stage 1 is to go through and cull any obvious direct duplication - i.e., where we have both peer reviewed lit and 3ary sources discussing the same thing, purge the 3ary source. Though there will still be LOADS of stuff afterwards, I fear. DanHobley (talk) 19:33, 16 October 2013 (UTC)

Thanks, Dan. Great suggestions. I'll make recommended change. Don't know how much time I'll have to spend on article. Looks like gov't shutdown is set to end and it's back to paid work. Cheers, Schaffman (talk) 20:30, 16 October 2013 (UTC)

Silver linings, I guess! Glad you're looking employed again. :-) I'm also going to be really tight on time for a bit, but I'll try to get some effort in. DanHobley (talk) 01:14, 17 October 2013 (UTC)

Proposed History Section

While off work, I drafted a fairly brief (5-paragraph) section on the history of Mars research regarding water. It's nontechnical, covering telescopic observations from Cassini to pre-space-age spectrographic findings and Mariner 4. However, I'm hesitant to add more length to article if subject doesn't add enough to make it worth while. It would also (alas) add some more references. I was thinking about placing it right after the introductory section. I may just go ahead and place it, letting you guys have at it. If you think it's too much material or otherwise needs reworking, let me know. I won't be offended. Schaffman (talk) 16:22, 19 October 2013 (UTC)

Thanks for adding images to section, BI. Looks good Schaffman (talk) 22:26, 19 October 2013 (UTC)

Section looks great, but maybe we should rename it for clarity. This is the history of discoveries, not a history of water on Mars, so it's a little ambiguous. However, I'm failing to come up with a succinct alternative right now. Anyone else? DanHobley (talk) 16:03, 24 October 2013 (UTC)

Adding to rocks and minerals section

I'm adding quite a bit of new material to the Evidence from Rocks and Minerals section because the section did not discuss the presence of water bound in hydrated minerals, which is an important part of Mars' water inventory. This is per the comment I made above. Schaffman (talk) 21:47, 23 October 2013 (UTC)

Hi User:Schaffman, that's nice stuff. But do you think it would be possible to either thin the text back a bit, or failing that, to introduce a subheading or two within the section? That's a big block of uninterrupted text to sit so high in the article. Maybe a picture or two would also help (maybe a nice CRISM image of some hydrated minerals, or something). I can have a go at subdividing into sections if you'd like, but probably not for a while (crazy busy right now...) DanHobley (talk) 16:01, 24 October 2013 (UTC)

Yeah, Dan I totally agree. Both ideas are very good. Realized the text was too long after I inserted it. I'll try some of your suggestion when I get time. Thanks a bunch for the feedback--Tom-- Schaffman (talk) 21:06, 25 October 2013 (UTC)

Looks way better now! DanHobley (talk) 01:51, 26 October 2013 (UTC)

Thoughts on article organization

I’ve been putzing around with article this weekend making minor editorial fixes. I’d be interested in getting some feedback on my thoughts about organization and other items.

1. Could we change the title of the Ancient Water Bodies section to “Geomorphic evidence” and move it above the Evidence from Rocks and Minerals section? Fluvial features such as outflow channels, valley networks are easily recognizable and understood by the layperson, and this new placement also follows the rough chronological sequence of discovery (Mariner 9, Viking, etc.) as laid out in the Historical Background section.

2. I don’t understand why inverted stream topography has a paragraph of its own in the current ancient water bodies section. These features are certainly very common on Mars but also IMO tangential to the main focus of the section. Perhaps the discussion should be moved down to another section. Maybe I’m wrong here. Any other thoughts?

3. Somewhere the article needs to have a brief discussion (1-2 paragraphs) on the Clifford (1993) model of the shallow martian crust consisting of a variably thick cryosphere underlain by liquid groundwater. I believe some form of this model is still the prevailing hydrological paradigm for Mars. Maybe this could be included in the groundwater section.

4. Organizing the article by spacecraft missions (probes) in the last part seems to add to article length and repetition. Could the info in these sections be weaved into the other sections?

Thanks for any thoughts/suggestions Schaffman (talk) 16:10, 27 October 2013 (UTC)

Hello. Last year when I did the article cleanup/overhaul (aka: (WP:Blow it up and start over), I addressed mostly the duplication of info and format. I also separated the research on past vs. current water. The current format is not the normal evolution of a Misplaced Pages science article, but the product of what I thought was a logical organization. I have only a basic education on planetary geology (3 elective courses only), so please feel free to modify the article format and info; I am glad whenever an expert addresses the actual scientific content of the article.

Regarding point #1, yes, "Geomorphic evidence" seems a most appropriate section title.

Point #2, inverted stream topography had a section before, I think it was created so a bunch of example images could be loaded in that section. I have no preference on your moving/expanding or reducing the related information; but if the feature is unique to Mars, I think that some info should remain.

Point #3: Go for it!

Pont #4: I was not sure what to do with it, so I just cleaned it up and placed it at the end; yes, that meant I did not address the redundancy in that section but I thought some readers wanted (and created) it as a alternative way of "classifying" or visualizing the same research on the subject. Lets discuss whether we and other interested editors want it deleted, changed or weaved into the existing info. BatteryIncluded (talk) 15:41, 28 January 2014 (UTC)

Stream water speed

@RJaumann: NASA's report () states that the water speed in that particular stream was about 3 ft/s (3.3 m/s). The German team apparently has been making improved calculations factoring Mars' weaker gravity, and I am all for including it, but not by replacing the current cited velocity. The abstract you bring forward does not display the calculated speed you keep entering, and the main research paper does not seem available online, which hampers being WP:verifiable. If you can find it, let's quote both estimates, OK? Cheers, BatteryIncluded (talk) 14:24, 11 March 2014 (UTC)

OR in Habitability Assessment

I know I posted about this about a year or so ago, but I'm trying again as, first, there have been developments in the last year, especially Nilton Remmo's team finding that water droplets form on salt / ice interfaces in experiments reproducing Mars conditions on Earth - and also I've turned up new citations to back up what I say.

The OR part is the sentence "Even at a depth of 2 meters beneath the surface, any microbes would likely be dormant". The reason that many scientists are now quite optimistic about the possibility of present day life on the surface of Mars is because as a result of new discoveries, they think there may be habitats on Mars where life can revive for a few hours every year.

The thing is, though the levels of cosmic radiation on the surface of Mars are far higher than for the surface of the Earth (protected by our thick atmosphere), they are comparable to the interior of the ISS.

Levels of cosmic radiation on the Mars surface

are the same as the levels within the ISS

Many micro-organisms can easily survive that, even if they spend most of their time dormant, so long as they are able to revive and reproduce, or repair damage. Radioresistant microbes are able to repair damage due to the equivalent of several hundred thousand years of Mars surface cosmic radiation within a few hours of revival from dormancy (they don't need to reproduce to do this, they repair their own DNA). For details: Deinococcus_radiodurans#Ionizing-radiation_resistance

Here is a citation to back this up, that microbes can survive cosmic radiation on Mars if they are able to revive:

"Finally there are other harmful radiation sources reaching Mars: ionizing and neutron radiation caused by galactic cosmic radiation and solar particle events.

"Due to the lack of a magnetic field and the low shielding of the Martian atmosphere (the Martian overhead airmass is 16 g cm instead of the terrestrial 1000 g cm) the doses of ionizing radiation at the surface of Mars reach values about 100 times higher than those on the Earth.

"However, since a great variety of microbes tolerate this type of radiation at similar or even greater doses than those found on Mars, ionizing radiation cannot be considered a limiting factor for microbial life on Mars and thus here we will limit our study to solar UV shielding and VIS radiation pentration."

(from RADIATIVE HABITABLE ZONES IN MARTIAN POLAR ENVIRONMENTS full text here pdf)

Recently several notable scientists have put forward the view that there may be life on present day Mars.

For instance, at the end of this video, Nilton Remmo says very clearly

http://www.youtube.com/watch?v=iLWv9UGwjdE#t=135

"Based on the results of our experiment, we expect this soft ice that can liquify perhaps a few days per year, perhaps a few hours a day, almost anywhere on Mars. So going from mid lattitudes all the way to the polar regions. This is a small amount of liquid water. But for a bacteria, that would be a huge swimming pool - a little droplet of water is a huge amount of water for a bacteria. So, a small amount of water is enough for you to be able to create conditions for Mars to be habitable today'. And we believe this is possible in the shallow subsurface, and even the surface of the Mars polar region for a few hours per day during the spring." (transcript from 2 minutes into the video onwards)

That's Nilton Renno, a professor of atmospheric, oceanic and space sciences at Michigan University who lead the research. He is also project scientist for Curiosity in charge of the REMS weather station on Mars, was on the Phoenix lander team, and author of Water and Brines on Mars: Current Evidence and Implications for MSL See also Martian salts must touch ice to make liquid water, study shows

The Encyclopedia Britannica says

"Despite this setback, the main driver of the Mars exploration program is still the search for life. Because liquid water is so essential for life, the initial focus has been on the search for evidence of warm conditions that would enable the persistence of liquid water. The evidence for such conditions at least on early Mars is now compelling, and there is some evidence that liquid water sometimes flows on the surface in a few places. The exploration thrust will likely shift to search for more-direct evidence such as organic remains and isotopic signatures. It could be argued that the best strategy is to look for fossil remains from the early period in Mars’s history when conditions were more Earth-like. But the Martian meteorite debate and disagreements about early terrestrial life point to the difficulty of finding compelling evidence of microbial fossil life. Alternatively, it could be argued that the best strategy is to look for present-day life in niches, such as warm volcanic regions or the intermittent flows of what may be briny water, in the hope that life, if it ever started on Mars, would survive where conditions were hospitable."

(from The question of life on Mars - Encyclopedia Britannica ).

And there was a conference on The Present-Day Habitability of Mars 2013 and in the course of the conference some of the speakers were upbeat and optimistic about finding present day life on Mars in these surface and near surface habitats.

Yes this is one of 17 habitability factors. But in the citations in the article, the first one just says "Solar particle events and galactic cosmic rays were considered external factors that occur infrequently or at low dosage, respectively", and the other one just lists it under "Some factors that may affect the survival and reproduction of Earth microbes on Mars". This doesn't mean that cosmic radiation is deadly for all life on Mars. We even have microbes living in reactor cooling ponds on the Earth.

Other scientists have also said the same thing. Even Robert Zubrin (who you might expect to be most skeptical about it) now says e.g. in a SpaceShow interview that he think there is a reasonable chance of finding present day surface life on Mars. And none of these scientists ever suggest that it is impossible because of cosmic radiation. Indeed it is a rare paper on this subject that mentions cosmic radiation at all. Usually they focus on such matters as UV radiation, the near vacuum conditions, the low temperatures, and high levels of salts.

So, that's why I call this assessment OR and WP:SYNTHESIS. It would be reasonably accurate as a reflection of our state of knowledge about six years ago when most scientists thought that all life on Mars surface is likely to be dormant. Robert Walker (talk) 13:59, 5 January 2015 (UTC)

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