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Recent Evidence Of Water On Mars Near Equator
mkasei writes "SpaceRef has an early press release with image from Brown University which reports evidence of recent liquid water near the surface of mars. What's important about this find is that it is near the equator making it more readily accessable for a mission, be it robotic or manned." Update: 07/25 09:49 PM by M : There's also a BBC story about water on Mars as well, and a brief Nature article about the possibility of water on Callisto.
In related news, NASA has also released an offer to bargain with commercial entitities who may wish to deal in the MARS TLD. ICANN, logically, has contested this.
You haven't been paying much attention to the latest on in-situ propellent production that has been pushed by Zubrin. Basicly you only carry the fuel required to get you to the destination and when you are there you start a small chemical plant that creates the required return propellant out of chemicals present in the martian atmosphere. It is a proven process however its the kind simple and elegant solutions that don't seem to sit to well with today's NASA.
After all, ice doesn't necessarily have to be water.
-B
Ash and Hickory, straight-grained and true, make excellent bludgeons, dandy for the cudgeling of vegetarians.
IANA Astronomer/Geologist/whatever, but why, when evidence of erosion patterns is found, do they always assume it was water that made them?
Why couldn't it have been some other fluid? Why don't they say it's evidence of some sort of luquid or fluid?
Can any knowledgable geologists help me out?
Recent satellite images of Mars reveal rust colored spots which scientists believe are Amelia Earhart's crashed airplane. "We believe Mrs Earhart was abducted by martians," said one scientist, "we think she had quite a life on mars and finally decided to try to fly her airplane around the planet. However she was unable to make it all the way around and crashed somewhere near the equator."
I'm trying to teach myself to set people on fire with my mind... Is it hot in here?
With budgets being slashed and Nasa having trouble getting robots to land, what does everyone think the reality of a manned mission in our lifetime is?
Weaseling out of things is important to learn. It's what separates us from the animals... except the weasel. -
-53C is the global average, rather than the equatorial average. Mars gets as warm as 27 C. The pressure is also dependent on the altitude, just as it is on Earth, and Valles Marinaris is 7 km deep. The highest pressure is up to about 9 millibars, well above the 6 millibars of the triple point of water. (See the nine planets for a handy reference).
In low-lying equatorial regions, you can temporarily get conditions that support liquid water.
Earth's atmospheric pressure is 1 atm or converting to kPa, 100 kPa. Martian atmospheric pressure is about 1% of Earth's or about 1 kPa (10^3 Pa on the chart). Average Martian surface temperatures at the equator are -53C or 220K. Now looking at our chart again, we see that at this point, water cannot exist as a liquid, but only as a solid (ice). As day/night termperatures shift, water will alternate between solid and gas only, never even passing through the liquid state, and once a gas, not likely to collect on the ground, but remain suspended as ice crystals high in the air. So for now, the collecting frozen water from near the poles, storing it in canisters , and transporting those to any camps remains the only realistic wat of getting water on Mars.
Not quite.
Liquid "water" is possible on Mars, in the form of brines - essentially, salts dissolved in water. Mix a bunch of table salt into a glass of water and put in in the freezer - some may freeze, but as it does, it concentrates the salt in the liquid portion until equilibrium is reached. Remember that pure water is rare, it is much more likely to have salt in it (Earth's oceans).
So, instead of looking only at the phase diagram of water, take a look at the binary or ternary phases diagram of water and various salts - some brines are liquids at -53C.
And there are other ways of making water on Mars - the atmosphere contains a few parts per million of water vapor. Yes, vapor, not ice. Run that past a zeolite bed, an extreme dessicant, and the level drops to a few parts per billion. Eventually, the zeolite absorbs about 20% of its mass in water. You then close the container, heat it up, and the water vapor is driven off to be collected and liquified. We don't have to go to the poles for water. The energy balance on this scheme works out to around 10 kWh per kilogram of water produced, quite doable with a few radioisotope thermal generators.
I recommend to every one Robert Zubrin's excellent book, The Case for Mars. You can buy it from the Mars Society, linked below.
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Vpered na Mars!
As one of the authors of the Nature article, I'd like to respond and say that it is not about liquid water, but rather about water ice. The ice collects in the dusty surface during certain climate conditions, then sublimates (solid->vapor) under warmer conditions. However, there are many situations that others have touched on that allow liquid water to exist on the surface of Mars under current conditions, at least temporarily. The phase diagram only tells us that it is not thermodynamically stable, not whether it may exist unstably (i.e. boiling away). This is a kinetic problem. Imagine that water exists in liquid form underneath the surface (i.e. the added pressure of the rock above moves you into a stable zone in the phase diagram). Then if some of this water is moved to the surface , it will take some time for it to freeze or evaporate. Again, though, this isn't the case for our terrain that we reported on in Nature.