Earthlike Mars? Options

[JohnVV]

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

[glennwsmith]

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 !!!!!!!!!!!!!!

[nprev]

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.

[centsworth_II]

Uh...Not to put a damper on the ecstasy, Glenn...

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?

[imipak]

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?

A new computer-generated map of the Red Planet provides a more detailed look at the valley networks on Mars, and indicates the networks are more than twice as extensive as had been previously depicted in the only other planet-wide map of the valleys. "All the evidence gathered by analyzing the valley network on the new map points to a particular climate scenario on early Mars," said Wei Luo, from Northern Illinois University (NIU). "It would have included rainfall and the existence of an ocean covering most of the northern hemisphere, or about one-third of the planet's surface."

[Phil Stooke]

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.



Phil

[JohnVV]

Oh dear... I dreaded this.

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

[Phil Stooke]

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

[glennwsmith]

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.

[nprev]

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.

[ustrax]

Content deleted - AstroBio rule Ustrax!!!!!

Naughty.


ADMIN

[ustrax]

Aaaaaargh!

[glennwsmith]

imipak, your post has really added some fuel to the fire; so let me ask this question:

If -- as now seems likely -- there was an Oceanus Borealis, do we really have the physics to account for its subsequent "sublimation" (I know this is not the correct word) into space; or is it not more likely that -- as I believe -- much or most of this ocean lies frozen still beneath the dust of the northern plains?

[Doc]

This research is quite interesting. But does not prove much as you guys have expertedly pointed out. The media are sure selling this discovery though...

However, what still strikes me as rather convincing evidence is the beautiful symmetry of the valley distribution. To say that they are random and so on would be rather unfair. Forgive me for being a little philosophical.

[mcaplinger]

If -- as now seems likely -- there was an Oceanus Borealis, do we really have the physics to account for its subsequent "sublimation" (I know this is not the correct word) into space; or is it not more likely that -- as I believe -- much or most of this ocean lies frozen still beneath the dust of the northern plains?

The likelihood that there was a lot of water on Mars at one time is old news (Mariner 9 at least) and certainly lots and lots of work has been done on the escape rate of water (see, for example, "Water loss and evolution of the upper atmosphere and exosphere over martian history", Valeille et al, in press at Icarus.) That paper concludes that "a conservative estimate of about 10 m of water is found to have escaped globally to space over the last ~3.5 Gyr."

I don't think that it's very controversial at all that there could be a lot of frozen water on Mars, so I'm a little confused by your implication that this is some big revelation and/or recent news. There is a long way between "has water" and "Earthlike".