And here's something hot off the press from the Imperial College of London which supports the possibility -- no, let's say probability -- of a frozen Oceanus Borealis. The link is as follows:

http://www3.imperial.ac.uk/newsandeventspg...-10-59-30#fni-2

Their thesis is that the Late Heavy Bombardment added huge quantities of water to the surfaces of both Earth and Mars. I quote briefly:

"They found that on average, each meteorite was capable of releasing up to 12 percent of its mass as water vapour and 6 percent of its mass as carbon dioxide when entering an atmosphere . . .Using published models of meteoritic impact rates during the LHB, the researchers calculated that 10 billion tonnes of carbon dioxide and 10 billion tonnes of water vapour could have been delivered to the atmospheres of Earth and Mars each year . . . However, researchers say Mars’ good fortune did not last. Unlike Earth, Mars doesn’t have a magnetic field to act as a protective shield from the Sun’s solar wind. As a consequence, Mars was stripped of most of its atmosphere. A reduction in volcanic activity also cooled the planet. This caused its liquid oceans to retreat to the poles where they became ice."

As Glenwsmith indicated on another thread, Oceanus Borealis is linked to the Meridiana lake/playa hypothesis. Taking another look at some of the features in the north it almost seems time to dust off some of Nick Hoffman 's White Mars observations, but with a view to reconsidering some of these northern outflow features as submarine water flow turbidites rather than Nick's proposed cyroclastic (CO2) cause.

The possibility that there is a frozen Oceanus Borealis beneath the dust of the northern plains has implications far beyond Mars, of course. If I may be allowed to speak in an enthusiastic vein for a moment, consider that Mars is only the second planet that we have been able to "sample". Finding large quantities of water there would thus, in a sense, double the amount of water likely to be extant among the universe's population of rocky planets.

The verification of an Oceanus Borealis also increases the liklihood that we will find significant quantites of water on our own moon; or -- to put this in negative terms -- if Mars is cold and dry, this does not bode well for the success of the current LCROSS mission to the moon.

By the way, I'm sure most of you are aware of yet another recent paper pointing to the presence, at least in the past, of a significant body of water on Mars; the link follows:

http://www.colorado.edu/news/r/7e9c22ec0cd...4ed2e29f16.html

http://www.lpi.usra.edu/meetings/lpsc2009/pdf/1939.pdf

One of a number of papers dealing with Mars Aqueous Processes on day 3 of the 40th Lunar and Planetary Science Conference 2009 held in March. Just a touch of home town enthusiasm in the CU media release page.

I looked at this paper after I was notified of the press release last week. Their "shoreline" is a fault scarp in alluvium, similar to this example from Nevada. I worked there 30 years ago. It can be difficult to distinguish shorelines from fault scarps across the alluvial fans in the Great Basin because they often are directly associated with one another. This example is "easy" because there's a graben in front of the main fault, but there isn't always one. In this valley ("Dry Valley" I think it was called, though the map software doesn't show the name) west of Caliente, Nevada, the paleolake was rather small and didn't rise to the elevation of the fault scarp.

Fortunately, of course, we could drive up to and walk on the feature to help us determine what it was.

In the martian example, we can't do that (not for a while, at least). So I'm afraid that in my view at least, the paper fails to provide the extraordinary proof that the claim "This is the first unambiguous evidence of shorelines on the surface of Mars" represents. ...in addition to it simply being an untrue statement.

-Tim

Yeah, I'm no expert on these things, but I cringed at the word "definitive." I also notice that the Wikipedia entry for Shalbatana Vallis has been updated with this info, including the word "definitive," which I think might be a little premature.

I hate the word "definitive." All it takes is a reasonable doubt to make one look silly for using it.

As a result, probably a lot of people think I'm less sure of myself than I think I am!

-Tim.

Agree that "definitive" is out of place in most articles, and particularly in this one. I'd just ease off the criticism a bit since this is from UC Boulder's press office, not from the researchers.

Well, they may not have used that specific word, but the title of the paper is "Positive Identification of Lake Strandlines in Shalbatana Vallis, Mars" and the abstract says "first direct evidence of strandlines" and the conclusions say "first direct evidence of unambiguous strandlines," which is about as strong a statement as one can make.

Even if the specific feature had merit (it doesn't, unless one is interested in local structural geology), the degree of certainty expressed in the paper is unwarranted.

-Tim.

Serpens, thanks for the link to the actual Shalbatana Vallis paper -- it's darned interesting; and tim53, thanks for making me want to take a closer look. The point is made in the conclusion that billions of years of aeolian activity (journalese for wind!) have eroded most former deltas and shorelines, but these in the Shalbatana Vallis have managed to survive to some greater or lesser extent -- making this area a possible candidate for future (Mars Sciene Laboratory aka "Curiosity"?) landings.

Also, is anyone out there good enough with the Hirise dataset to be able to post a non-3D, maximum resolution image of the area represented by Fig. 3A in the paper? (This shows the putative shorelines.) I would be forever in your debt.

I suppose it would help to see the images before registering a "definitive" opinion on the subject.

But on its surface, the word definitive is rather strong. Even if the paper does not actually use that word and it is a reporting error, it does say "first direct evidence". As far as "first" is concerned, I doubt it. "Direct evidence" maybe somewhat subjective. I want to see the images in unambiguous HiRise first.

FYI: NOVA's latest Mars show, "Is There Life on Mars", does an excellent job summarizing the latest results & discoveries from MRO, Odyssey, Phoenix, and MER.

http://www.pbs.org/wgbh/nova/mars/

It also briefly describes:
-- the giant-impact theory for the northern basin
-- possible climatic history
-- comparison on how Meridiani was very acidic with evaporite deposits, yet the chemistry of where Phoenix sampled was slightly basic (Calcium carbonate!), lightly salty, with perchlorate present (and how perchlorate may improve the chances for microbial life).

Too sad, it's only available for the audience in the USA .

I really would love to watch "Is There Life on Mars?".

I imagine life could certainly have occurred on Mars in the past and may still be present today provided there is sufficient water underground. We know from the Martian flood channels that there were once vast TORRENTS (hint hint) of water on the surface.

Well....looking at the morphology of the channel networks, it appears that the channel networks were not formed by rainfall, but rather from subsurface reservoirs.

Check out:
Gulick, V.C. Geomorphology 37 (2001) 241-268. "Origin of the valley networks on Mars: a hydrological perspective." (pay for article, link here)

Fully freely accessible articles (confess I haven't read these yet):
http://www2.ess.ucla.edu/~nimmo/ess250/baker.pdf

Carr and Head, GEOPHYSICAL RESEARCH LETTERS, VOL. 30 (2003) , NO. 24, 2245. "Basal melting of snow on early Mars: A possible origin of some valley networks". doi:10.1029/2003GL018575
(accessible here)


The Gulick (and others) articles give very good evidence that the valley networks were formed from subsurface sources (amphitheatre-headed valleys, very low drainage densities, low-Strahler order networks with high bifurcation ratios, etc.).

The valley networks are also very localized. One example in the Gulick article was of a dense valley system in Warrego Valles that was situated along a topographic break - yet neighboring areas also on the topographic break (same geology, same climate) were totally devoid of channels.

Their hypothesis is that Mars was covered in snowfall and melted in a few places due to magmatic activity and released water catastrophically. Other regions of snowfall that didn't melt quickly simply sublimed away slowly.

Well, yes! The word torrent, according to wikipedia "generally signifies a strong flow of something, especially fluids and particles". By using it I was not implying that the channels were caused by precipitation.

Here's an interesting reference (on an interesting site) to Oceanus Borealis (about halfway down the page):

http://oklo.org/2006/12/

For those who wanted to watch the NOVA show Is There Life on Mars? produced by PBS; the full show is now freely available for streaming in six "chapters." ( 1 Hour show )

QuickTime or Windows Media Player streaming formats are provided.

NOVA: Is There Life on Mars?

You won't get a review from me. No way!

But only available within the USA

Quite by chance I found that I could watch it on my laptop - then realised it was because I was running Hotspot Shield (http://anchorfree.com), a freebie on a recent cover disk. As a side effect, Hotspot Shield appears to confuse the server into thinking I'm in the US...

Rob
(UK)

I apologize. I don't see anything about that on the web page. They fail to mention it in the technical help section also.

Just a reminder to participants in this thread (which should really be entitled "Oceanus Borealis") that we are fast approaching the climax of the LCROSS mission to search for water at the lunar south pole, the results of which have a major bearing, it seem to me, on whether we can also expect to find a frozen ocean hidden beneath the dust of the northern plains of Mars.

Hmmm. Not sure on that. If I got it right, the volatiles on our Moon were delivered by comet impacts long after it's formation, spraying volatiles all over, some of which settled in cold traps (permanently shadowed craters).

The water on Mars presumably was there from it's formation and is residual from it's early days.

(Trying to figure out predicted H/D ratios, here....Mars should be HDO enriched from several cycles of evaporation/sputtering-loss of lighter mass H2O/recondensation. The Moon on the other hand should be closer to the primordial H/D ratio - thes more H2O. If anything ever evaporated it would be a one way trip off Luna....)

Yet another indication of -- dare I say it -- water on Mars:

http://spacefellowship.com/2009/09/15/evid...e-beds-on-mars/

And in reference to Oceanus Borealis, the idea as I understand it is that a meteor impact can melt part of the underlying frozen ice ocean, which in turn dries up to leave the polygonal formations which we see today.

If those cracks are so ancient, why aren't they filled here and there with dust?

I would say that ground cracks that aren't filled up with dust occur because the process of dust deposition v. deflation has achieved a dynamic stability on Mars. The winds giveth, the winds taketh away...

-the other Doug

There's a new report out that results from the Indian lunar mapper (announcement coming up) indicate that there's "lots" of water on the Moon

If that's the case, then there's "lots^^2" water on Mars. I believe, in fact, that we are establishing a new paradigm -- just as we are now learning that planets are plentiful in the universe, so we are also learning that the rocky bodies among them are loaded with water -- Mars, the apparent desert planet, included.

I know this is the kind of wild statement that cautious thinkers abhor, but I can't help it -- it's in my genes.

BTW, I think Fran asked a good question about the desiccation cracks and the other Doug had an equally good answer.

Two back-to-back articles on the JPL web site about water on the moon and Mars, respectively -- in the unlikely event that there's a UMSFer somewhere who has not yet seen them:

http://www.jpl.nasa.gov/news/news.cfm?release=2009-147

http://www.jpl.nasa.gov/news/news.cfm?release=2009-148

Sept 24, 2009 -- a big day for space junkies indeed.

hhmmm! So water ice and sublimation is a much more significant process on Mars than previously thought...not a big surprise to me personally. The big surprise is the Moon. But if comets brought water to Earth, then it makes sense that they would bring it to the Moon too.

It wouldn't have stayed on the moon very long, though, if it came from comets. Current thinking seems to be that the lunar water is produced by the solar wind. I'd doubt if very much (if any) Martian water arrived that way.

--Greg

"Water" on Mars guys! Ice visible at mid latitudes from HiRise: http://www.spaceref.com/news/viewpr.html?pid=29232
BTW, Astro, where is the new emoticon you shown us recently?

The identification of ice in a new crater is a good find. But I feel that Shane Byrne is a bit quick off the mark to claim cause and effect and state that "This ice is a relic of a more humid climate from perhaps just several thousand years ago."

Ice underlying the regolith within centimeters of the surface as a recent deposit - perhaps. A relic of an older warmer wetter past - perhaps. Or the residue from ice meteorites that left icy residue that gradually sublimated. The latter would seem more in keeping with the observation that the ice was a thin layer overlying darker material.

i think we should perhaps revisit Viking 2 science results...any news from the radar team as to th thickness of water ice in mid latitudes of Mars??

Well, at the scalloped terrain of Utopia Planitia (46º) the sublimation pits are quite deep:

http://www.unmannedspaceflight.com/index.p...mp;#entry127173

Are we sure those craters spotted recently are impact craters or explosive??water ice sublimating ?similar to the spider structures seen at the poles except that the mechanism for the latter seems to be C02!

If you can suggest a method by which they can suddenly appear, in a cluster, with ejecta and occasional airburst patterns....go for it.

Does anyone have a sense of the distribution of these ice paved craters relative to the presumed outline of Oceanus Borealis? And a related question: do these craters all fall within basins or low lying regions, or regions which were at one time low lying?

In an earlier post in this thread, I made the not-original observation that the many pairs of trained amateur eyes of UMSF members could play an important role in interpreting the visual evidence for an Oceanus Borealis.

That concept has now been endorsed in a big way on APOD, but in reference to galaxy structure. It's pretty darned interesting:

http://antwrp.gsfc.nasa.gov/apod/ap091026.html

and to think i made this image 6 years ago ( 100% fictous ) based ONLY on an average mola height
1024x512
Click to view attachment

too much ice ,no weathering , ...
it dose need to be remade

JohnVV -- way cool! My effort understandably did not pass Phil's muster, but perhaps yours will!

mine is so old and has almost 0 scientificly included data it is just an "Artistic" interpertation
It dose look nise though ,I did get a request from a componey to use it in a video for Nat'l Geo chanel

Re the recent LCROSS press conference: At least some water at lunar poles = LOTS of frozen water -- indeed, an Oceanus Borealis -- under the dust of the northern Mars plains !!!!!!!!!!!!!!

Uh...Not to put a damper on the ecstasy, Glenn, but we are talking about two completely different planetary bodies with equally different environments & apparently radically different means of acquiring/depositing water in their polar areas.

Don't think that you can reasonably infer an a=b relationship here.

Maybe he's just speaking semantics: If a few buckets full can be a lot of water on the Moon, then an Olympic pool volume of water on Mars can be an ocean.

Is Mars jealous? Are we making too much of the Moon's shiny new outfit?

Luo and Serpinski, "Computer-generated global map of valley networks on Mars" in JGR-Planets (Abstract) is picking up a fair amount of coverage. (e.g., ScienceDaily, Universe Today.) The visualisations look plausible to this layperson; can anyone comment on the methodology?

Oh dear... I dreaded this. It all looks so good. But it's based on computer analysis of topographic data. It shows where water would flow, but it does nothing to prove that water has actually flowed in those locations. The same algorithm applied to a lunar highlands topographic data set would identify similar valleys (Hint - someone please try this!). Sorry, but there it is. Here's a bit of Apollo topography (digitized stereo contours made into a DEM) from my atlas. Look at the topography on the rim of the Crisium basin. This algorithm would fill it with valleys.

Click to view attachment

Phil

your statements above ARE one of the reasons i state that my map is 100% artistic

we do know that water was ( and is ) there juts not where and when the water was
0% information ( close to that, maybe 5% ) for what areas had it and when they had it .

and this will not change much until we have "boots on the ground" and can study it

The map is very nice - but look how it's suddenly taken up in the press as proof of an ocean. It is suggestive, but so was the previous work. The fact of mapping more valleys than past workers did does not by itself prove there was more water. To my mind, every valley identified here must be compared with good modern images to determine whether or not it is real. I'm not trying to put down the hard work of doing the mapping, but I don't trust watershed algorithms very much. They create their own reality.

Phil

imipak, a most interesting post! And Phil, your points are well made also.

The thing that impresses me about the trajectory of modern astronomy is how familiar a place the universe is turning out to be. The surface of our own planet is four-fifths water; we have seen entire moons of Saturn and Jupiter which seem to be nearly 100% water worlds; and we have now found water on the moon. So I am not going to be surprised if the Mars map which imipak has pointed us to turns out to be correct.

True. Considering that even the lunar maria were considered literally that not too long ago (relatively speaking), we seem to have had a predisposition to think of 'water on a planet' in terms of oceans by analogy with the Earth. No oceans=bone dry.

The thing to be wary of is swinging to either extreme (again!); the truth always lies somewhere in between.