New Mars Forums

Yes, Mars apparently does have [http://marsprogram.jpl.nasa.gov/newsroo … 0306a.html]a molten core. but i think the crust will compress and bouce back to a certain extent on its own regardless. the molten core idea as far as im aware is mainly implicated in that volcano vs ice age theory about the heavy ice sheets compressing the mantle and core to alter tectonic plate interactions and, like hydraulic fluid, squeeze out more volcanic activity to effect global cooling and warming cycles and ice ages.

The concept of ice sheet rebound is something I hadnt considered on Mars before, but it follows and might help explain why the area of Meridiani is now a very gentle slope (i cant find the reference, but thats what i read anyway), not suggestive of a probable site for a water basin, as a result, the mission scientists had discounted the possiblilty of a sea being here early on.  So perhaps the topography looked different when this area was covered by a heavy ice sheet which eventually melted into a shallow (or deep) ice sheet and berg-covered sea, and then, as the weight was relieved by the dissapearance of the ice and water, the terrain slowly bounded back from its basin-like topography to the gentle grade we see today.

I remember reading some old article years ago about a probe that, if they had started building it at the time, would be arriving at Alpha Centauri around 2020. The probe was to be powered by microwaves or laser beamed from earths vicinity. The amount of power needed to do this essentialy relegated the idea to a pipe dream.

I found [http://www.space.com/businesstechnology … 217-1.html]this intersting article:

As an aside, order can be seen in many non-living and non-entropic systems. Hydrophobic membranes form as spheres without any real enegy input other than thermal movement merely due to the properties of the molecules they contain, much like magnets will assemble end to end without losing any energy to the system. Minerals crystalize when they lose heat and assemble into the pattern of least resistance. This doesnt mean that the ordering is active and requires an entropy cost (well, it does lose heat in the process, but thats a cause not an effect), the "information" that crystals or membranes or magnets typify is merely dictated by the natural laws. Not that I think this supports or refutes an argument for a god-ful or god-less universe, just an observation (and needless to say i might not be entirely correct in my understanding of it), i just dont think it necessarily takes energy to create information (order).

all phases of water and lots and lots of brine...

its interesting how when driving on hwy 80 north of Reno Nevada, in the hot dry summer through barren desert wasteland there is an expansive wet marsh of briney water that just doesnt seem to ever dry up, perhaps its a water table or something because its so hot and windy there it should evaporate away in just days, but it stays wet somehow and the plants and birds just love it. we know brine lowers the freezing point, but does brine signifficantly retard evaporation as well?

I'd assume that there might be anologs to such a desert marsh on Mars, perhaps the briney water table is dusted over and not very noticeable by visual cues, but there might be other ways of inferring the existance of such a marsh...

Yep, hotspots in Hellas Basin. Here is [http://www.abc.net.au/science/news/spac … 917757.htm]an old article on it.

Mars still has a [http://marsprogram.jpl.nasa.gov/newsroo … 0306a.html]liquid core, it follows that there shoudl be a little bit of thermal heat still escaping to the surface.

I remember reading somewhere that if they are vents and there are ice towers over them, then they shoudl be visible as a white speck even to MGS.

its about time someone started testing again...

...wouldnt want to get rusty.

Wasn't there an approach of beaming an extremely powerful laser at the sail from the Earth or Moon or from the Space Platform, so you wouldnt have to accelerate all that heavy propulsion equipment and fuel? just a couple hundred kilograms for a science payload and radio transmitter... if the laser doesnt lose much coherency over distance, you could keep accelerating it as long as you can budget, although if it gets going too fast thered be no way to slow it so it would fly by its destination too fast... better pack a 'light' parachute!

New scientist doesnt have the article online. Was there any reference to the "Stalks" or "dimples" like those seen so often by Opportunity?

The spherules themselves i believe are completely geological, i dont really buy into the "potato roots" life theory of the stalks and dimples that someone here suggested (even though i really think its a very interesting idea!).

Early on in the mission, I was thinking the spherules would prove to be tectites, due to the dimples (vessicles left over froom venting gas), an idea to which i was supremely disheartened by since it seemed to effectively cast the landing site as a baren life-less wasteland. But from what i have heard, concretions don't form dimples, so I was at the same time very excited and puzzled by the determination that they were concretions (eureka! water!), deepening the geological (arelogical?) story to be teased out of the area.

However puzzling as this is (and I love it how Mars keeps throwing curve balls at us), my initial guess is that the spherules underwent repeated series of soaking and drying out which caused mineral migration from inside and outside the spherules, this would  probably tend to form a singular area weakness "dimple" from mineral-laden leaching entering and leaving a hardened area downstream of the leach flow which could be fossilized as the "stalk".

has anyone heard any explanations of the "stalk" and "dimple" features?

Deep layers of sediment cover Eagle crater and the surrounding plains. There is bound to be a "bottom" to these sediments, and if Endurance crater is young and deep enough, its impact might have punched lower than this bottom level. revealing evidence of older rock formations that pre-date the sedimentary layers that may have been formed either slowly or relatively quickly by repeated catstrophic flooding.

The lack of rocks at Eagle crater and its general area is quite puzzling... If the crater were younger than the layers, there should be more crater ejecta rocks strewn about the surrounding plains. From what ive read, Meridiani has been undergoing a wholesale removal of topsoil by wind erosion so its not merely that the rocks are covered up, they should be concentrated at the surface like the pebbles and spherules are. It makes me think that the craters pre-date the layers and the sediments were deposited atop these features.

The [http://www.lyle.org/mars/imagery/1P1337 … 1.JPG.html]only only sizeable rock we see sitting on the surface at Opportunity is probably not crater ejecta, and preliminary spectra suggests it contains hematite, whatever this might mean... Perhaps this rock was dropped off by an ancient iceberg. Maybe the sediment layers are deeper than Endurance can reveal and well just see deeper layers of sediment. Im guessing that as we look deeper layers there will be less evidence supportive of life, given that life likely increases with time and the upper layers should prove more fruitful...

Its odd that NASA hasnt commented on the odd pictures, especially if it were a problem with the tool, and it seems they have gone on to other tasks: It seems [http://www.lyle.org/mars/imagery/2M1338 … 1.JPG.html]these latest MI images might be about getting some sort of atmospheric particulate data by occulting the sun with the tool and reading the diffraction of particulates in the atmosphere, thats what it looks like a bit anyway... If indeed the RAT has a leak, it might not be a "failed UniBus address register", but [http://en.wikipedia.org/wiki/Snafu]SNAFU or TARFU

Alternatively, the crater may have indeed been seriously smashed to smithereens and have been formed long after the ancient spherule-laden sediments were lain down, this would assume the erosion has exhumed and removed the areas where the impact had melted and shattered the bedrock, which seems to be consistent with the exhumed nature of the terrain seen all over Meridianni. consider this scenario:
1) sediments lain down and altered by liquid interaction, vugs, spherules, "fossils" and all forming over the eons.
2) meteor hits forming Eagle crater, exhuming and melting sediments to a certain depth
3) considerable time passes with more water intervention and altering of sediments (do impacts cool or warm mars?)
4) more eons of erosion take away several feet of surface, sand-blasting bedrock and exposing deeper features that were mostly unaltered by the impact, other than fracturing (we do see lots of cracks in the bedrock). However, erosion couldnt go too deep or there'd be no crater left to see...

Which brings me to a puzzling observation: The lack of rocks at Eagle crater and its general area.
The bedrock seems to degrade to a fine talc-like powder that quickly blows away and collects in places with less wind action as can be seen in [http://www.lyle.org/mars/imagery/1P1336 … 1.JPG.html]these images Im betting they will determine the spectra of the white dust to be the same as that of the bedrock showing this white dust is just eroded bedrock. There are no chunks of bedrock on the surface because it erodes relatively quickly and would have long ago dissolved and blown away. The [http://www.lyle.org/mars/imagery/1P1337 … 1.JPG.html]only lonely large rock we do see sitting on the surface is probably not crater ejecta, if this were an impact-thrown rock, shouldnt we be seeing many more of them strewn about, especially right next to a crater?? maybe they arent buried, and this rock is not an impact ejection. perhaps, given the probable climate, there was likely to be iceberg activity that carried rocks from elsewhere and deposited them in odd places far away just like what happens on Earth. therefore, the spectra taken of this rock should show it is unrelated to the bedrock or spherules. If it is related, shouldnt we be seeing lots and lots of rocks everywhere, especially considering that the Meridiani terrain appears to be getting gradually exhumed, and isnt being covered up by dust or sand to hide such debris. The wind should take away all light bedrock particles and leave a terrain of strewn rocks like what we see at Gusev and other sites. But if the sedimentary layers go deep enough, no rocks will be in reach of Eagle-guage meteor impacts. Therefore, it seems likely that Meridiani hosted a very very long-lived body of liquid water so there is likely to be a great depth of sediments that is still being exhumed. so the rocks that are underneath all these sediments may be like what we see at places like Gusev, but are still buried deep.. and i wonder how deep, hopefully well see some evidence at Endurance if wind erosion debris doesnt collect too deep there...but i'm not a geologist, this is task-chair speculation...

Yeah, lots and lots of spherules littered around everywhere, presumably the bedrock has been getting exhumed and blown away with the wind, leaving a huge littering of sperules everywhere like desert pavement forming as the bedrock dissolves and blows away from under them, concentrating them at an ever-sinking surface.

A large number of the spherules are broken in half. but why? how hard or brittle are they? now how is that, if theyre iron hematite, did they crack? temperature shock? shoudlnt they be more durable? note that some were half broken and still embedded in the bedrock so some had to have broken before the bedrock was created.

what in [http://www.lyle.org/mars/imagery/1P1334 … 1.JPG.html]the heck is this ? the heatshield? somehow i'd thought it would be much farther in the distance. oops! no its just that chunk of rock taken from [http://www.lyle.org/mars/imagery/1N1332 … 1.JPG.html]different positions and [http://www.lyle.org/mars/imagery/1P1333 … 1.JPG.html]vantage points so it only appears at first like it has different backgrounds. its deceiving how big this stuff seems to be but this is really pretty close given the parallax, so this chunk of rock that looks like its probably as big as a footlocker is probably only about a foot wide, whad'ya say?

The [http://www.lyle.org/mars/bysol/1-059.html]Opportunity SOL 59 images look most otherworldly, reminds me what an alien experience it is to watch new pictures from another planet get sent in every day. the closeups of the white soils almost looks like it could be an orbitter photo. so is this white soil merely exhumed bedrock dust collecting on the leeward side of the crater rim? is it also what composed the white crusts in teh little crater feature next to the lander that they bulldozed?

On the other hand, I think its all to likely that the deeper layers of bedrock will be even less likely to contain any fossil evidence, since in my view, life probably reached its peak of abundance and diversity in the topmost dozens of layers that weve already been examining at Eagle crater.

At this point Mars might have lost its life-favorable surface conditions and at the same time of course, also stopped accumulating layers of sediment. Therefore, the deeper layers should contain less fossil evidence, and certainly not any large multicellular fossils that we'd be able to see with the MI. At the heart of this theory is the idea that sediment accumulation goes hand-in-hand with abundance of life, and if sediment accumulation stops that would mean that the conditions favorable to life stopped as well. And life shoudl increase in its abundance and diversity as time progresses.

Alternatively, the most life-bearing layers could be deeper assuming that layer accumulation continued after life died out (life may not have been eliminated by the surface conditions changing and were killed off by other means). And Mars could have been covered-over with many eons of apparently lifeless sediment accumulation, or the only life that survived was microscopic and no macroscopic fossil evidence was being laid down after this time. The larger the layers in the bedrock would tend to suggest more changing the conditions were (catastrophic flood conditions) at the time the sedimentary layers were laid down, so these layers might have been laid down before it was stable enough for life to get a foothold and diversify. Unless life is beneath these large layers, indicating catstrophic end to macroscopic life on Mars.

Or maybe life never reached macroscopic levels and all well ever see is evidence of bacterial excretions such as layers of organics and microbial mats.  IMHO I think the "termite gallery" features in the bedrock might be evidence of differential erosion produced by the existance of mineralized microbial mats, but im not a geologist or biologist, does anyone have any insight into this idea?