New Mars Forums

I guess you could also probably use the abundant electical power to power a electromagnetic mass driver and shoot a stream particles (taken from asteroids) towards the top of the atmosphere, blowing off bit by bit, but i guess that would take eons, either deploying millions of atmosphere-skimming orbiters that would use captured solar to power to expel the captured atmophere mass regain their lost momentum each pass or by steering an heavy asteroid into an atmosphere-skimming path that should help plow away some extra mass, but this still just seems too slow of a process to be effective...

- I think some sort of new technology, either biogenetic atmospheric processing microbes that could chemically alter the atmosphere into more appropriate molecules using a solar or chemical gradient as an energy source, or devise devices to be deployed ubiquitously across the surface of Venus to do the same sort of chemical processing...

not to digress too far off-track this thread, but, basic question here, whatever happened to Venus' original water? did it get chemically combined into minerals or is it blended in the atmosphere?

Yeah, escape velocity would seem to be a deal-breaker... i cant say im convinced there could be a "just the right angle" of impact to minimize the debris trajectory enough, but i guess if in the first place you had the technology and energy budget to be able to move comets around at will, then you probably would have the capability to dismantle them into many smaller more manageable chunks that could be a cleaner operation. If not, then tens of cubic miles of ice and moon debris splashing away from the impacts would most likely end up raining and crashing down on Earth... 

i was hoping to find somethig more written on it and what exactly the calcs were. i just had happened to see Harlan give a talk last year and he was very enthusuastic about it. but thats the last i heard about it, im not too sure about those numbers i recalled...

In the latest (July/August) issue of The Planetary Report magazine, there is an interesting response in the Q&A section by Chris McKay that details some surprising (to me at least, as i havent read much of the terraforming threads) projections for terraforming Mars:

- So I thought that lack of a magnetic field was a death-knell in itself to terraforming plans, since anything on the surface would get fried and the naked atmosphere would get blown away. However, since Mars' gravity is much lower than Earth's, it will take much more mass per unit volume to reach 1 Earth atmosphere pressure at the surface (1 kg/cm2 for Earth vs 2.6 kg/cm2 for Mars), therefore the radiation shielding offered by this extra gas mass will easily more than account for the sheilding effects provided by an Earth-like magnetic field, which only deflects the low-energy protons anyway. The radiation is less intense at more distant Mars than it is at Earth. Therefore, Mars, even without any magnetic field at all, would actually be better shielded from radiation than the Earth is (!)

- The atmosphere won't get blown away like some might think, the atmospheric loss on Mars is only equal to about 2 meters of water over 4 billion years, which doesnt seem like very much anyway, apparently a thicker atmosphere wont blow away any faster than the current thin one because the gravity holding the atmosphere to the planet remains essentially the same and since the solar wind doesnt increase (i guess those low-energy protons the magnetic feild deflects dont have much effect on the atmosphere?), it merely displaces the same amount of atmosphere it would in any instance, regardless of how thick it is.

...this is more than enough time and protection to set up shop on Mars. This analysis further suggests to me that Mars really hasnt lost very much of its water at all, it probably had a thick atmosphere in the past, its just that the water froze underground back when the sun was cooler and the atmosphere dwindled when the temperatures were too low to drive a greenhouse effect in those conditions to resupply more gasses in the absence of volcanism. Since it seems there is plenty of ice below ground, if we can budget a technique to create thick enough atmosphere, it could probably be brought past a self-reinforcing temperature feedback tipping point, given the sun's current heat output, bringing us much closer to sunbathing on our own beachfront property on Mars (if we can only live long enough to transplant our brains into clone body replacements).

Now thats the shot i've been waiting for:
http://mer.rlproject.com/index.php?act= … ...id=1569
look like theyre made from shots taken on http://www.lyle.org/mars/bysol/2-219.html]Spirit sol 219
Now, look just right of center on the horizon, is that Bonneville Crater poking up?
I've wondered just how far we've come but not been able to spot Bonneville in any pictures taken from the flats we crossed, now that weve gotten this perspective it looks so close! and pretty steep there inthe distnace too. its really great to finally get some higher perspective to give a more cognitive sense of the path travelled that just cant really be done justice by tracing lines on an orbital photo. now if i could only make out Spirit's tracks leading all the way to the crater...

Does the "Olivine problem" really preclude long periods of water? the more i read, the less im convinced of that.
http://mineral.galleries.com/minerals/s … e.htm]some data on Olivine

heres an http://www.psrd.hawaii.edu/Nov03/olivine.html]article about Olivine on Mars in which it states:

Well, it sounds like a few main Olivine caches exist mainly i Ganges Chasma and Nili Fossae, but since theres not much free oxygen or water to weater it away into rust or clays, any erosional releases from these caches should stick around for quite a while, so its apparent concentration in any area could build up as wind erosion continues.

On the flip side (and maybe i'm missing the real crux of why Olivine is expected to be so rare on Mars), doesn't the argument that Mars Olivine is so unexpected also beg the question that we shouldnt be seeing any Olivine on Earth either since its always so wet here, but Olivine isnt exactly uncommon is it?

I thought the natural decay of radioactive elements had long been assumed to create a big part of any planet's heat, although i guess were talking about nuclear fission here, as opposed to merely radioactive decay. Either process should keep Mars somewhat molten. I'd assume that this process should be even more likely in the planet's interior than in the crust, and would there be any evidence of it at the surface? could radioactive waste migrate upwards with lava or gasses? On the other hand, im wondering how much of Earth's interior heat is generated by tidal action? http://www.curtin.edu.au/curtin/centre/ … tml]fossil reactor info

http://www.newmars.com/forums/viewtopic … ]indeed-->

Thats a great site, Ive been following it for the last several months. He puts forth some interesting observations, sometimes in a more skeptical fashion than most fossil-fanatics out there. I sent him a description of one of my dubious "fossil finds" and he refuted it.

That sharks]http://www.xenotechresearch.com/mk009.htm]sharks' tooth and snail shell image is actually http://www.lyle.org/mars/imagery/1M1289 … JPG.html]a microscopic image that would barely fit a US penny across the whole field of view. Those shells and teeth are extremely small, not that that negates the fossil-origin argument, but as the first image of the soil that Oppy took, its intersting that we havent seen much more of these types features. This image has the best Martian snails shells ive ever seen.

Great idea, i hope NASA is thinking the same thing. But on the flip side, I hope they dont really go into "full" hibernation but instead use a little power (if any can be budgeted) each day to advance a few easy meters, so we can edge towards the etched terrain and cut weeks off the time needed to make up that difference when they do decide to wake them up. After all, it might be best to keep the parts moving, lest they seize up just sitting there...

About dust accumulation, aside from shaking the dust off of itself as it bumps along, the rover itself should be a good experiement of that. Its actually difficult to see from the images how much dust there is since exposure differences between the images tend to mimic just what dust build up would tend to look like anyway, but i think i see some  http://www.lyle.org/mars/imagery/2N1446 … noticeable dust accumulation in this picture from sol 206 that doesnt seem to be there in http://www.lyle.org/mars/imagery/2N1324 … .html]this old picture of the same solar panels from sol 69. most notably the shading across areas of the panels seems to suggest signifficant dust build up. These are both taken from the same filterless navcam so only atmospheric/sun angle/exposure differences exist. It does look like at least http://www.lyle.org/mars/imagery/2N1446 … PG.html]in this image from sol 206 that dust is accumulating more heavily on the outside edge of the rear panel, perhaps the wheels tend to kick it up in a way so more settles here.

Now, if you could only reach out across the millions of miles with a finger and scribble "wash me"!

Haven't heard anything about this really, my thoughts are that the low gravity might not pack the soils as densely, thereby making the soils fluff away from under the wheels, the rover pretty much spinning the rug out from under it as it did trying to get out of Eagle crater, maybe cancelling out any such low gravity advantage...

There is bound to be some "sweet spot" where the weight of the rover helps the wheels track better on the varying type of soils below it. As the rover encounters an incline, if its too light the wheels cant get a bite and spin atop rolling grains, too heavy and the wheels just plow and bog down. I wonder if we're close to that in the MERs? i'm not sure how much the MERs weigh, but i remember reading in some other thread somewhere that the surface area of the wheels is less than desireable for the rover weight since they had to be small enough to fit inside the landing package (i guess it would be too unreliabile to consider some sort of mechanical doo-hickey expanding wheel design to get more surface area after landing).

any soils specialists out there?

No special instruments shoudl be necessary to detect ice...
I'd have to say that if the white sheen were ice, it would be pretty obvious if NASA chose to take a closeup picture of it (wouldnt it tend to crytalize and form a quite different texture than the dust?), and NASA certainly has taken many pictures to investigate the wheel-disturbed areas. But, perhaps these are only look-alike areas, and arent the areas Gil is talking about, and freshly-pressed-out-of-the-soil mars ice may just look like white dust from a couple feet away! but I really doubt that. I choose to be somewhat gullible about the potential for life on mars (at worst, the power of wishful thinking keeps us looking harder!), but about this mud, im just not coerced. Dont get me wrong i hope we find liquid water or at least exposed ice or brine at Mars, and I really do think well see some surface water at Meridiani, but it will probably be in the form of frost as the winter progresses, at least there are the clouds that suggest water vapor closely overhead here.

Rgcarnes,
Is scattering why iron oxide looks red and titanium oxide is white, something like that? maybe im misunderstanding some basics here. But anyway i was suggesting that the whiter stuff is whiter because it is made of finer and lighter powdery particles that tend to blow away leaving meridiani topsoil very dark, even if the lighter and darker materials are made of the same matter, because i didnt see any other way how the stuff below the topsoil should tend to be whiter than the stuff on top (unless it has to do with solar radiation) other than the lighter particles blowing away (like desert pavement effect), other than if they were truly different compositions and contain frozen-out brine like Levin suggests. Or perhaps dew and frost has modified the soils and concentrated salty minerals into dust-clods by capilary action or other means, now dry, the white powder comes from inside these dust-clods when they are broken up when the rover smashes them. regardless, this aspect is quite mysterious...

Shaun,
thanks for your detailed treatment on the Martian surface temps and humidities, i never know it was that extreme. That seems to suggest those beautiful clouds Opportunity snapped last month are actually very very close to the ground! However, this devils advocate, though not being a meteorologist, would think that if the saturation point is so tight, shouldnt there be lots of fog forming in many places on Mars with the generous supply of nucleating dust in these supersaturated conditions? maybe the "haze" we see in the rover photos not just dry dust, but a thin water vapor fog?

Also, those airbags sure should have picked up a heck of a lot of static electricity bouncing around on dry ground like that, and the "magic carpet" effect (electrostatics?) seemed to only occur under the airbag retraction area.  i wonder if anyone knows more about this, NASA must have worked out calculations to safeguard the electronics from this static build up, maybe even measured it in situ?

Ammonia hoax... so they jumped the gun...

but...
   So then, what exactly causes it to break down in Mars' atmosphere? and how is it that http://www.jpl.nasa.gov/solar_system/pl … tml]Uranus contains AMMONIA as one of the main constituents of its atmosphere? if it breaks down so readily in an environment as "gentle" as Mars compared to something like Uranus, im thinking it probably couldnt possibly be a relic from the formation of the solar system..? what kind of processes create it there? please advise.