Dry Mars?

robnissen · Sep 20, 2007

Contrary to the researcher quoted here, I find this very disappointing news: http://www.space.com/scienceastronomy/070920_mars_tale.html While I agree that gaining knowledge is a good thing: In science, discrediting a theory can be just as important as supporting one. "Some science reporters are acting as if we should be disappointed these new bright deposits weren't deposited by water," McEwen said. "We're excited by any advance in understanding Mars no matter what it is." I also agree that discrediting a theory is imporant, nevertheless, I especially find this disappointing: Dry landslides McEwen led another research team, which studied a variety of landforms also thought to be associated with past water on Mars. They examined images of gully deposits that had been detected last year by the Mars Global Surveyor. The gully deposits were not present in 1999 images but appeared by 2004. The before-and-after images raised hopes that modern flows of liquid water created the deposits. However, observations from MRO suggest a dry origin, McEwen said. Both chemical analyses and images of one of the fresh deposits showed no signs of frost or ice and no evidence for even hydrated minerals, all of which could have given the deposits a "bright" appearance. "We think dry landsliding could've created the bright deposits," McEwen said. The slopes above this deposit and five other locations are steep enough for sand or loose, dry dust to flow down the gullies, the scientists say. Material uphill could be the source. Its not that I reallly disagree with anything substantively here, but I think the attitude is simplistic. While increasing our knowledge is a good thing, we can't increase our space knowledge without f

jaxtraw · Sep 21, 2007

Well, I've thought for some time that Mars is going to disappoint, at least all those banking on water and life as justification for exploration. It's almost certainly IMV a dead place, dead as a doornail. I'm most strongly persuaded of that, as James Lovelock was all those years ago, by the fact that it seems to be in chemical equilibrium. If life were there, it wouldn't be. THis is what troubles me about idealistic plans for the future of space. Mars is, pretty much, only of interest to geologists. Colonisation, beyond a couple of hugely expensive Antarctica-type research stations, would require somehow doing what plants have spent billions of years doing for Earth- using solar energy to generate an active biosphere. It just doesn't seem feasible. Life is what makes Earth so dynamic. Life created the oxygen atmosphere. Without life, everything just reacts until it's in chemical equilibrium, and stays that way. A space programme based on looking for life, looking for water, is going to run out of steam, because once we've shown Mars is just a lump of rock with a thin veneer of CO2, and no practical use, we're rapidly running out of any further reason to acquire knowledge about the place. How many more maps of an uninhabitable world do we need?

Aetius · Sep 21, 2007

I've long thought of terraforming Mars as an unnecessary waste of time and money, that would pose many dangers and entrench a powerful and meddling global authority that I would quickly come to despise as a colonist. Few things would make me happier, space-wise, than a dead Mars. Native Martian life, of however limited extent, would probably compel Earth people to stick their noses where they don't belong.

adrenalynn · Sep 21, 2007

While I might tend to lean towards Jaxtraw's assessment, I'm not sure I could get on board with you Aetius. Exactly how would you go about defining "Earth people to stick their noses where they don't belong"? Is that any attempt to gain knowledge about anything outside of our current planetary abode? Or is it inclusive of things here? Just some general quest for knowledge? I'm not sure that it fits with the (what I consider to be appropriate) standard human thirst for knowledge. To remove that is to remove what makes a human in the first place. Now we're *all* just "sheeple". [edit to correct misspelled nom-de-plume ] <div class="Discussion_UserSignature"> .bipartisan (bī-pär'tĭ-zən, -sən) [Adj.] Maintaining the ability to blame republications when your stimulus plan proves to be a devastating failure.IMPEACH OBAMA! </div>

Aetius · Sep 21, 2007

I want Mars to be colonized by humans, and I want humanity to learn every bit of information that can be gleaned from Mars. My vision of Mars, though, is a patchwork quilt of dome-based and underground city-states, linked with the Earth-Moon system by treaties and trade. Terraforming will inevitably lead to a powerful global government on Mars, in addition to being monstrously expensive for the future Martians themselves.

adrenalynn · Sep 21, 2007

If a government (aka a "people") fund it, shouldn't said government (people) have a strong and firm hand in its future? <div class="Discussion_UserSignature"> .bipartisan (bī-pär'tĭ-zən, -sən) [Adj.] Maintaining the ability to blame republications when your stimulus plan proves to be a devastating failure.IMPEACH OBAMA! </div>

Aetius · Sep 21, 2007

I could live with that as a compromise. Were I to live on Mars, I just wouldn't want to have my city-state's every act of self-determination to be subject to the whims of an overweening planetary government, in the name of maintaining the Blue Mars status quo.

Aetius · Sep 21, 2007

If the people decide to fund terraforming, it will be one more thing for taxpayers to support; in addition to: Health care, education, life support, colonial militias, welfare and care for the elderly, research of all kinds, et cetera.

dragon04 · Sep 22, 2007

Define "dry". That could have multiple meanings. The Sahara Desert is "dry", yet there are oases and inhabitants who sink wells to provide water for their existence. In the case of Mars, there is compelling evidence that a lot of water is both locked up as ice at its poles, and frozen underground in other locations. IIRC, if all the water ice was liberated in a sufficient atmosphere, Mars would be covered 3 meters deep globally by water. This indicates that the atmosphere of Mars declined as a function of time as opposed to a single event that would have allowed Martian water to boil off into space on a short geological time frame. A lot of water apparently froze out rather than boil off. In that case, Mars is not a "dry planet". <div class="Discussion_UserSignature"> "2012.. Year of the Dragon!! Get on the Dragon Wagon!". </div>

brellis · Sep 22, 2007

hi jaxstraw banking on water and life as justification for exploration. - like most earthlings, I'm a big fan of both water and life <img src="/images/icons/wink.gif" /> I agree that a dead planet isn't as sexy as a live one, and popular support for exploration is driven by hope and fascination. I get the sense that the average U.S. taxpayer doesn't think NASA is wasting money, even if the cool parts get their attention only occasionally. So, a base of support exists for the time being, and surely some adventurous billionaires will pick up the slack on future manned missons to the moon, Mars etc. In short, I feel optimistic that we'll continue to explore and learn, even if we confirm that life doesn't exist elsewhere in the solar system. One hopeful question: what's producing the methane on Mars? A biogenic source hasn't been ruled out, has it? <div class="Discussion_UserSignature"> I'm a recovering optimist - things could be better. </div>

3488 · Sep 22, 2007

A biological source has not been ruled out 100%, but is on the wane. More likely the methane is from internal aerological activity, venting, etc, rather than biology. I suspect Mars is & has always been as dead as a doornail regarding life. Having said that, life should not be the focus of the exploration of the solar system, because if it is, than unfortunately the entire exploration programme will be cancelled, because there is none to be found in our Solar System, besides Earth (other solar systems, that's a different matter). Solar system exploration will throw new light on volcanism (Io, Venus, Earth, Moon, Mars), cryovolcanism (Titan, Enceladus, Dione, Ariel, Titania, Oberon, Triton, Pluto, Charon, Eris, 2003 EL61, Quaoar, etc), chemistry in differing environments (just about every object in the solar system), impacting processes (Mercury, Moon, Mars, Callisto, Rhea, Umbriel, etc). However, the geology, well aerology & history of Mars is fascinating in its own right & those points alone, more than justify the continued exploration of the fourth rock from the Sun. Look at what we have seen recently with the Saturn moon Iapetus, yet we know for sure there is no life there. The history & the set up of the Solar System as is, is more than worth the exploration effort. We know of huge reserviors of water ice at the Martian poles (proven beyond any doubt), but this notion of liquid water exposed on the surface is just pathetic, other than short bursts, before it freezes or evaporate. Remember the amospheric density at the Datum Line on Mars is the same as Earth's is at 30 KM / 19 miles above sea level, together with the Sun's average intensity being 44% that as on Earth. Andrew Brown. <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

MeteorWayne · Sep 22, 2007

Cool, we get to diagree, Andrew! I think we will eventually find evidence of microbial life on Mars. It may take a decade or two, but I feel pretty confident in my belief. <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

3488 · Sep 22, 2007

Hi MeteorWayne, I hope very much that you are correct & that I am wrong on this. I just have my doubts, lack of global magnetosphere, deperately thin atmosphere, etc, but in the ice deep down, perhaps why not. I would lave to see a deep core sample be drilled perhaps at a very low point like Hellas or Argyre & have it properly analyzed. I just hope that you are correct friend. Andrew brown. <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

jaxtraw · Sep 22, 2007

Well, I'm no Green, and I don't agree with the grander Gaia hypothesis, but I entirely agree with Lovelock's initial point that life modifies its environment. We see no sign of that on Mars, nothing. It has every appearance of a lifeless planet. I can't say there's definitely no life there; what can be said is there is absolutely no evidence that there is.

brellis · Sep 22, 2007

I don't agree with the grander Gaia hypothesis... I can't say there's definitely no life there; what can be said is there is absolutely no evidence that there is.- well, I'm a Planet-Hugger! <img src="/images/icons/cool.gif" /> I will attempt a crude, optimistic connection of the dots: As scientists probe subterranean locales on earth, they've found bacteria that might live for millions of years, never seeing the light of day. They've found creatures living next to hydrothermal vents. They've revived bacteria that had been laying dormant for hundreds of millions of years. From a Nat'l Geographic Article on Mars Aquifers:Stunning color pictures from Mars offer new evidence that plentiful groundwater once percolated through Martian bedrock. The new images, taken by NASA's Mars Reconnaissance Orbiter, reveal a terrain of banded rocks similar to that found in the southwestern U.S., said Chris Okubo, a postdoctoral researcher at the University of Arizona's Lunar and Planetary Laboratory. The new pictures show that Martian rocks in this sandy landscape are riddled with small cracks. These cracks bear telltale signs that fluidâ€”probably waterâ€”seeped through them hundreds of millions of years ago. Prominent riblike structures along the cracks, for instance, suggest that running water dissolved minerals in the Martian soil, forming a kind of cement. The water also dissolved dark minerals out of the rocks, leaving light-colored "halos" around the cracks. These findings are exciting, because th <div class="Discussion_UserSignature"> I'm a recovering optimist - things could be better. </div>

3488 · Sep 25, 2007

Got an update here from the NASA / JPL site. The dry nature & origin of the gullies is confirmed. <img src="/images/icons/frown.gif" /> However some in Vallis Marineris do appear to be hydrated, so this is not a total blow out for a dry Mars. There is ice present in huge quantities at the poles, just whether or not there is ice at lower latitudes is the elusive question. Andrew Brown. <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

paulscottanderson · Sep 25, 2007

The newer deposits may indeed be just dry dust slides, but there is still the previous evidence that the original formation of these or other gullies was water-related; two different things: http://mars.jpl.nasa.gov/mro/newsroom/pressreleases/20070920a.html "Other gullies, however, offer strong evidence of liquid water flowing on Mars within the last few million years, although perhaps at a different phase of repeating climate cycles. Mars, like Earth, has periodic changes in climate due to the cycles related to the planets' tilts and orbits. Some eras during the cycles are warmer than others. These gullies are on slopes too shallow for dry flows, and images from Mars Reconnaissance Orbiter's high-resolution camera show clear indicators of liquid flows, such as braided channels and terraces within the gullies." Paul <div class="Discussion_UserSignature"> -----------------The Meridiani Journal a chronicle of planetary exploration web.me.com/meridianijournal </div>

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