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Mounting Evidence for Water on Mars
Kent Simon writes "Space.com has an interesting article discussing new evidence from the mars rovers that shows there may really be Water on Mars."
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OK we all know that water is needed to sustain life on earth, which is why its such a biggie when the possibility of water on extra-terrestial terrains arises.
But what is it exactly about water that makes it so important? Here is a page which shows some of the most important properties of water. It shows, for example, how capillary action works, a property that allows plants up to 20 feet (i think!) tall to absorb water without using any energy whatsoever!
but it also has Hydrogen Peroxide in the atmosphere!
link
Antiseptic and life-killing, the chemical helps explain why the martian atmosphere and surface are void of life.
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From the little I remember from geology, wind blown (aeolian) sand grains are more likely to be angular, while grains move by water are rounded. This is one indicator used to distinguish the provenance of a sedimentary rock at outcrop.
There have been at least two expeditions to the Arizona desert by NASA people to study dust devils, both run out of the University of Arizona. I had the opportunity to spend a month in the Arizona desert gathering data on the second trip.
I wouldn't say that NASA is particularly concerned about dust devils -- due to the lower gravity, dust devils on mars would be much weaker than those on earth, even if they are larger. Even on earth, dust devils post little threat. Some of the ones we studied were over 2 miles tall, and you could walk right through them with absolutely no danger. While the original trip was sponsored by the HEDS (Human Exploration and Developement of Space) funded Matador experiment to see if the dust devils posed any danger to human exploration, the primary concerns were over static electricity and dust getting into space suits.
What NASA is really interested in is how dust affect the geology of the planet. In the absense of water or strong winds, dust devils may in fact be the primary erosive force on Mars. During the first half of the 20th century, astronomers noticed that Mars changed color depending on the season, and this led them to beleive that there was rich vegetation on Mars. When the first orbiters and lander arrived, we learned that this wasn't quite true, but we still had no other solution. Now, scientists believe that is was dust devils, which are a seasonal occurance, that were actually reconfiguring the landscape of the planet. We have actually seen pictures of light colored planes that are crisscrossed by dark dust devil trails.
The problem is that very little is known about dust devils on Earth. I only know of one scientific paper published on the subject. While some of the work we did was trying to find out the proerties of dust devils, especially the electrostatic properties, to help create an accurate model for their formation on Mars, this was not really why we were there. The primary goal of the NASA researchers was to study the dust devils on earth in order to learn how to study them on Mars. We were mainly out there to test a set of instruments planned for Matador (including some far out stuff, like using a special UV camera to detect sparks caused by static electricity).
If anyone is interested, there is an article on the first trip at:a .html 0 5/29_dust.html
http://www.spacedaily.com/news/mars-atmosphere-01
and the second trip at:
http://www.berkeley.edu/news/media/releases/2002/
ESA decided to send one orbiter and one lander to mars, NASA decided to play safe and sent out not one but two landers, Spirit and Opportunity. And of course, they have their own orbiter, too.
Orbiter? Try Orbiters -- there are two existing orbiters -- Mars Global Surveyor and Mars Odyssey. The MER missions did not orbit.
But when you look at the actual scientific data produced by both the ESA and the NASA mission, you will see that NASA definitely does the better PR work. But what have they produced so far? A few snapshots and panorama pictures (which are nice, but well...)
You don't really have a clue, do you? First, some of those "snapshots" are from the Pancam, which has a variety of narrow-band filters to allow detailed image analysis. Second, the rovers have been collecting a TON of data from the other main science instruments -- MiniTES, Mossbauer, APXS. While these don't produce pretty pictures (just boring spectragraphs), it's a wealth of scientific information.
and some stone probes. But due to their design, they can't drill down further than maybe a few meters (if even that deep).
"Stone probes"? WTF are you talking about? The rovers can essentially spin a wheel in place to carve out a trench in the soil. That can dig in the ballpark of 6 inches. There's also a RAT tool to grind rocks, which only goes a few milimeters -- that's all you need to get past any dust or weathering.
This isn't a sub-surface exploration mission, so complaining about that is like saying Slashdot sucks because there's not enough advice on cosmetics.
but IMHO, it's not really something special: we've seen pictures from mars before, and we've analyzed probes from mars before.
We've never seen pictures like the microscopic imager is taking. And it's naaive to say that just because a couple of previous missions have takes pictures that there's no value in doing anything similar again... For simple example, look at how radically different the Opportunity site is from the other missions (Spirit, Pathfinder, Viking I&II).
So, I'm a lot more impressed by the work done by ESA: although they lost their lander (what a pity...), they concentrated not so much on the PR (no "the best crew in the world!" cheering) but more on actual science
That's an insult to everyone in NASA working on the MERs. Have you ever done any real science? It's obvious you don't know anything about the NASA mission, but to make a blanket statement like that about the science just a couple of weeks into the mission is stupid. It can take months to years to develop all the final results.
Let's look at your other ESA claims:
produced detailled 3D maps of parts of mars which has never done before, and where the big geological structures can be analyzed better than ever before.
Uhm, no. NASA has been making maps since the Mariner and Viking missions in the 60's and 70's. More recently, the MGS and Odyssey orbiters have been producing higher-resolution imagery. MGS has even taken pictures of the rovers on the surface (see http://www.msss.com/mer_mission/index.html).
proved the existence of water on the south pole of mars. NASA asserted that they had detected that in 2001 already, but in fact, they didn't, because they didn't have the right equipment. All they were able to detect at that time was hydrogen, which is a possible indicator for water, but definitely not a prove.
It would be more accurate to say "confirmed," no "proved." ESA's PR is in hyper-overdrive here. Previous results from other missions (especially Odyssey's neutron spectrometer) have led to the forgone conclusion that water/ice is present. ESA's results are an "independant cconfirmation," but are hardly a novel or shocking result.
measured the actual temperature on the mars surface (up to +4 degrees Celsius), which is higher than estimated before.
Aga
Sorry, but the ESA orbiter showed this more than a month ago. NASA is just too late
It is obvious that you didn't read the article. The editor's post of the story was a little misleading because we've known about water on Mars for some time.
Having said that, the article states that they think they are actually SEEING liquid water freeze as it's being pressed upward out of the soil by the rover's wheels. That's much different than detecting it with an orbitor. Also, if I'm not mistaken the ESA orbitor suggested that water vapor exists in the atmosphere, not the soil. The missions are complimentary (ESA and NASA have been assisting one another by relaying commands through both of their orbitors and NASA has been trying to actually find Beagle visually using their orbitor). No one is taking credit for anything they haven't done. No need to get defensive.
Hmmm, you should have paid attention in your freshman physics class. No such thing as "negative pressure." What you meant to say was "lower relative pressure" and even then you're still wrong. Even if the leaves managed to lower the air pressure above their surface to zero psi, which of course they can't, the highest you can lift water via air pressure differential is 10.3 meters. A water column 10.3 meters high weighs as much as a column of air reaching from sea level to the top of the atmosphere.
If you want to move water to the top of a sequoia, you've got to use some mechanism other than air pressure differentials. In fact, had you carefully read the page you linked to, you would have noticed that transpiration peters out at around 32 feet.