Skip to comments.Ice store at Moon's South Pole is a myth: study
Posted on 10/19/2006 6:41:12 AM PDT by presidio9
Hopes that the Moon's South Pole has a vast hoard of ice that could be used to establish a lunar colony are sadly unfounded, a new study says.
In 1994, radar echoes sent back in an experiment involving a US orbiter called Clementine appeared to show that a treasure trove of frozen water lay below the dust in craters near the lunar South Pole that were permanently shaded from the Sun.
If so, such a find would be an invaluable boost to colonisation, as the ice could be used to provide water as well as hydrogen as fuel. NASA is looking closely at the South Pole as a potential site for the United States' return mission to the Moon, scheduled to take place by 2020.
But a paper published in the British science journal Nature on Thursday by a US team says the Clementine data most probably was misinterpreted.
Donald Campbell of Washington's Smithsonian Institution and colleagues collected radar images of the Moon's South Pole to a resolution of 20 metres (65 feet), looking especially at Shackleton crater, which had generated most interest.
The team found that a particular radar signature called the circular polarization ratio -- which in the Clementine experiment was taken to indicate thick deposits of ice -- could also be created by echoes from the rough terrain and walls of impact craters.
The signature was found in both sunny and permanently shady areas of crater, which suggests that the reflection comes from rocky debris, not thick ice deposits.
If there is any ice at the South Pole, it probably comes from tiny, scattered grains that probably account for only one or two percent of the local dust, the authors suggest.
"Any planning for future exploitation of hydrogen at the Moon's South Pole should be constrained by this low average abundance rather than by the expectation of localised deposits at higher concentrations," the paper says soberly.
The research involved sending a radar signal from the Arecibo telescope in Puerto Rico. The signal hit the southern lunar region and the reflection was picked up by the Green Bank Telescope in West Virginia.
Of course if you increase the mass of the Moon, you will change the orbital characteristics (and climate, seasons, tides, etc.) of Earth. That's not a trade I want to make.
Not only did I not suggest doing this to the moon, the post you quoted me on says specifically "Mars" so I'm not sure where you're going. We were talking about getting Mars to hold on to an atmosphere. The Moon is better off without one, for my purposes. Not to mention that it's lower gravity is a positive, as well. Enough gravity to keep stuff where you put it, not enough to keep from getting to someplace else relatively easily.
I don't think there's enough mass in all the asteroids, combined, to raise Mars' mass that much.
[ http://www.nineplanets.org/earth.html ] Earth mass: 5.972e24 kg
[ http://www.nineplanets.org/mars.html ] Mars mass: 6.4219e23 kg
Okay, now I'm 90 per cent sure.
Wouldn't the ice burn up before it gets into space? And if it is going to be shielded by the rocket, that would seem to make it very expensive.
And I just answered a 'help wanted' email -- they wanted somebody to process payments to the ice store.
Hey, there aren't even any eskimos to buy it down there, are there?
Now I'm not so sure either. I must have had "Moon" on the mind. I guess that makes me a lunatic.
What's the water for? Well, for life support, or for electrolyzing into propellants--you need LOTS of power for that--and then you have to lift the propellants back into orbit. Any payoff comes from the more modest gravity well of the Moon.
The payoff--if there is one--is S-L-O-W.
First, the sun is readily available as the base source of consumable energy. Fairly unlimited supply.
Second, whether we breathe it or burn it, the oxygen and hydrogen are not lost, they are transferred to a new compound, CO2 and H2O. The basic law of conservation of matter. Transforming them back into oxygen and hydrogen is again a question of the application of energy.
The supply of base elements is the major factor in living on the moon, not the supply of energy. Energy provides the means to manipulate the elements as needed.
It might be of interest to note that the moon appears to be 30% oxygen by weight. The missing element is hydrogen of which there are traces only.
If we added Mercury (which is denser than Mars but smaller obviously) to Mars, the little virtual calculator gizmo I've got here puts the combined mass at 9.7219E23, which is 16 per cent of the Earth's. Venus' mass is 81 per cent that of Earth. There really isn't any way to find enough material to make Mars like the Earth.
If there were lots of water available to bring Mars' mass to that of the Earth (and there could be), Mars could be converted to a planet with a planetary ocean, Earthlike atmosphere (synthesized from frozen gases imported from the outer Solar System, which is where the water could be lurking), and floating cities for humans. The final diameter of water-covered Mars would be larger than that of Earth, because of lower density.
Current Mars is just under 11 per cent the mass of Earth. Moving nearly 90 per cent of the Earth's mass is well in the future. IOW, the only practical prospect for the foreseeable is to build habitrail-style habitats on Earth (could be just inflatable structures) and deploy them on Mars, inflating them with the Earthlike atmospheric mixture, and staying indoors. :')
You mean there's no ozone hole on the moon?
The moon is an entire ozone hole. Pole to pole.
and staying indoors.