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NASA Probes Reveal Vast Stores of Martian Ice
John Faughnan writes: "The BBC reports that a British newspaper has leaked stunning news from the Mars Odyssey spacecraft. Vast amounts of water ice are present on mars, "[if it] were to melt it could cover the planet in an ocean at least 500 metres deep." Researchers thought it would take a year to detect any water ice below the martian surface, but the huge quantity meant that weeks of observation were sufficient. The BBC notes that "The Mars Polar Lander was to touch down in exactly the right spot in 1999 and would have undoubtedly detected the ice had it not malfunctioned on the way down." This discovery will change plans for upcoming probes and may lead to a manned mission within the next two decades. The official announcement was scheduled for this Thursday prior to several publications."
This is a serious step ahead for the feasibility of a terraforming project. I'm reading the Mars series from Kim stanley Robinson at the moment, this article is spot on!
I don't quite understand how the discovery of ice on mars would make manned missions any more possible. Don't they take water with them on missions anyway?
If its already there, it means that you don't have to bring it with you (or at least not as much).
Water can be used in the production of oxygen, and also fuel (after you break down into Hydrogen and Oxygen). These things require a LOT of water... much more than we could possibly hope to bring with us.
Discovery of water also means that the chances of finding life (or at least sign of primative life that once existed there) are much, much greater.
As explained here, earth bacteria survived on the moon for 2 years.
IIRC, they sterilize some space probes by blasting them with radiation before launch.
I was happy ina kind of boyish school kid kind of way about reading this. I don't really think it makes that much difference in reality to the actual *need* or feasability for a permanent manned Mars base, because the Mars northern polar cap always had water ice (or was it the southern one? in any case one did) and a manned base would have had to melt the stuff anyway.
The long term effect of this is that perhaps our descendants will be able to terraform the planet as envisaged by Kim Stanley Robinson and this is the kind of news piece that NASA needs to get public support for a Martian base, although, as I said above, in reality it doesn't change things that much.
To the guy who warned about Radiation poisoning from solar storms on the trip to Mars. Ship designers have been thinking about that one for a long time and this is where the concept of a storm cell on board a ship comes from - a thick walled cell whose walls are basically water tanks to absorb the radiation i.e. ionised particles.
NASA already has materials that would be used to protect astronauts on such a long voyage. While cosmic rays are pretty much impossible to stop, they are somewhat rare (on a solar scale). Solar flares would be a huge problem, but NASA has come up with a "safe area" inside any proposed Mars craft that the crew could go to during intense flares. The shielding was (IIRC) a type of lead foam composite that provided excellent protection for much lower weight than solid lead.
And let's not forget that even though the ISS, Mir, and Skylab were all within the protection of Earth's magnetosphere, astronauts have been exposed to the Van Allen belts before and shielding protected them adequately. This isn't an insurmountable problem by a long shot.
In the end they will lay their freedom at our feet and say to us, Make us your slaves, but feed us. - Fyodor Dostoyevsky
http://themis.asu.edu/
be sure to check out the pictures. very cool
don't hit *the* (read: 1 aka single) webserver too hard. i don't want to have to walk across campus and explain what happened =)
as such, posting AC !
Arranging the tanks and compartments that carry such stuff to provide a solar storm safety shelter in the center of your "tin can" is a trivial design exercise. A meter or two of water between you and the radiation is pretty much all you need. The ambient radiation is a problem, although only in percentage terms (it slightly increases your chance of getting cancer sometime later in your life). The point has been made that you could recruit the crew from smokers; they couldn't smoke on the mission; and you would actually decrease their chance of getting cancer during their lives by sending them to Mars!
Many, many design studies have been done utilising exactly the design I mentioned above, and it works. Read about it in this book or at this website.
Fans of the old SimEarth game will fondly recall Hellas as the best place to aim ice asteroids early in the Martian terraforming process; being at such a low altitude gives Hellas the highest atmospheric pressure on Mars, so liquid water has the best chance of lasting long enough to do some good if you collect it there.
When all you have is a hammer, everything looks like a skull.
Blockquote:
Equate average molecular thermal energy (3/2)kT with kinetic energy (1/2)mv^2 and you get v=sqrt(3kT/m). Where k is Boltzmann constant (1.38e-23 J/K), T is in Kelvin and m in kg.
Now O_2 has mass 2( 2.66e-26 kg) = 5.3e-26 kg.
And H_2 has mass 2( 1.67e-27 kg) = 3.3e-27 kg.
Which comes from atmoic weight / Avogadro's 6.022e23 = grams/molecule.
Say room temperature is 79F, 22C, 295K then O_2 is zipping around at 480m/s or 0.48 km/s (about 1000 miles an hour), similarly the average H_2 molecule is going at 1.9 km/s.
The escape velocity for Earth is 11.2 km/s and for Mars 5.0 km/s.
So at first glance earth can hold onto the average O_2 and H_2. Which is clearly not the case (Earth!=Gas giant). The rule of thumb is if the average molecular speed is greater than 6 times the escape velocity then it stays, otherwise it leaves.
So 6*O_2 speed is 2.88 km/s, 6*H_2 speed is 11.4 km/s. So H_2 leaves earth's 11.2 km/s escape velocity, and O_2 is still well within Mars's 5.0km/s.
If you use bc to check the math, set "scale=30" to avoid div zero.
So... there is no indication we have to worry about massive melting. Icebergs breaking off the ice shelfs is natural and not an indication of global warming. Those parts of Antartica that the gloom-and-doom environmentalists expect to warm up, melt, and flood our coast are actually getting colder.