Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: neilep on 29/07/2007 16:32:53
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Here on earth we benefit from the protection of the earths atmosphere !
........ how will we deal with the protection that we won't have that the earth atmosphere currently affords us ?....... if we live on the moon ?
Don't write most of your answer somewhere else....right it at-most-here !! *groan*
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Clever Sheepy! LOL... How will we deal with not having the protection that the earth's atmosphere affords us if we are living on the moon? Is that what you meant... like the sun the water etc.. what is the temperature of the moon.With it being dark, would it be very cold.. if so we would have so many things to adapt to on top of shelter etc. Does the weather there change, No rain I suspect as there has been no water correct? That is a good question Neil. There are tons of differences Gravity or the lack of it being the least of the problems..
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There is no weather on the moon (apart from the slight solar weather effects), as the moon does not have its own atmosphere.
Temperature is misleading, because again the lack of atmosphere means there there is no convection, and little conduction, so the only means of changing temperature is through radiation (it is rather like asking is it not dangerous carrying very hot, or very cold, substances in a vacuum flask - but the vacuum protects you from the temperature differences).
The risks on the moon are no different from the risks in space, except that you have the benefit of a little gravity. Protection from those risks would be the same as protection from similar risks in space.
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That is very interesting I did not know that about the lack of weather! Does anyone know the temperature? So Neil Refers to the protection we won't have.Would this not include building environments that will sustain life for centuries like some kind of environmental dome or massive shelter that will be self sufficient if that is possible!
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http://www.nasa.gov/worldbook/moon_worldbook.html
The temperature at the lunar equator ranges from extremely low to extremely high -- from about -280 degrees F (-173 degrees C) at night to +260 degrees F (+127 degrees C) in the daytime. In some deep craters near the moon's poles, the temperature is always near -400 degrees F (-240 degrees C).
It has to be said again that the temperatures are only radiative, no wind chill factors, or other convection heat exchange. Turning daytime temperatures into night-time temperatures is no more that putting up an umbrella. But even at night, it will take a long while for heat to dissipate (depending on the surface from which you are losing the heat).
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http://en.wikipedia.org/wiki/Colonization_of_the_Moon#Disadvantages
There are several disadvantages to the Moon as a colony site:
- The long lunar night would impede reliance on solar power and require a colony to be designed that could withstand large temperature extremes. An exception to this restriction are the so-called "peaks of eternal light" located at the lunar north pole that are constantly bathed in sunlight. The rim of Shackleton Crater, towards the lunar south pole, also, has a near-constant solar illumination. Other areas near the poles that get light most of the time could be linked in a power grid.
- The Moon lacks light elements (volatiles), such as carbon and nitrogen, although there is some evidence of hydrogen near the north and south poles. Additionally, oxygen, though one of the most common elements in the regolith constituting the Moon's surface, is only found bound up in minerals that would require complex industrial infrastructure using very high energy to isolate. Some or all of these volatiles are needed to generate breathable air, water, food, and rocket fuel, all of which would need to be imported from Earth until other cheaper sources are developed. This would limit the colony's rate of growth and keep it dependent on Earth. The cost of volatiles could be reduced by constructing the upper stage of supply ships using materials high in volatiles, such as carbon fiber and other plastics, although converting these into forms useful for life would involve substantial difficulty. The 2006 announcement [6] by the Keck Observatory that the binary Trojan asteroid 617 Patroclus, and possibly large numbers of other Trojan objects in Jupiter's orbit, are likely composed of water ice, with a layer of dust, and the hypothesized large amounts of water ice on the closer, main-belt asteroid 1 Ceres, suggest that importing volatiles from this region via the Interplanetary Transport Network may be practical in the not-so-distant future. However, these possibilities are dependent on complicated and expensive resource utilization from the mid to outer solar system, which are not likely to become available to a Moon colony for a significant period of time. One of the lowest delta-V sources for volatiles for the Moon is Mars, suggesting that developing colonies on Mars first may in the long run be the easiest and least expensive way to establish a colony on the Moon.
- There is continuing uncertainty over whether the low one sixth g gravity on the Moon is strong enough to prevent detrimental effects to human health in the long term. Exposure to weightlessness over month-long periods has been demonstrated to cause deterioration of physiological systems, such as loss of bone and muscle mass and a depressed immune system. Similar effects could occur in a low-gravity environment, although virtually all research into the health effects of low gravity has been limited to zero gravity. Countermeasures such as an aggressive routine of daily exercise have proven at least partially effective in preventing the deleterious effects of low gravity.
- The lack of a substantial atmosphere for insulation results in temperature extremes and makes the Moon's surface conditions somewhat like a deep space vacuum. It also leaves the lunar surface exposed to just as much radiation as in interplanetary space. Although lunar materials would potentially be useful as a simple radiation shield for living quarters, shielding against solar flares during expeditions outside is more problematic.
- Also, the lack of an atmosphere increases the chances of the colonial site being hit by meteors, which would impact upon the surface directly, as they have done throughout the Moon's history. Even small pebbles and dust have the potential to damage or destroy insufficiently protected structures.
- Moon dust is an extremely abrasive glassy substance formed by micrometeorites and unrounded due to the lack of weathering. It sticks to everything, can damage equipment and it may be toxic.
- Another subject that needs to be touched by NASA are the scientific concepts attached to moon exploration, including permenent oxygen reproduction and storage.
- Growing crops on the moon faces many difficult challenges due to the long lunar night (nearly 15 earth days), extreme variation in surface temperature and solar flares. The use of electric lighting to compensate the 28 day/night might be difficult: a single acre of plants on Earth enjoys a peak 4 MW of sunlight power at noon. Experiments conducted by the Soviet space program in the 1970s suggest it is possible to grow conventional crops with the 15 day light, 15 day dark cycle. A variety of concepts for lunar agriculture have been proposed including the use of minimal artificial light to maintain plants during the night and the use of fast growing crops that might be started as seedlings with artificial light and be harvestable at the end of one lunar day. One estimate suggested a 0.5 hectare space farm could feed 100 people.
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http://en.wikipedia.org/wiki/Colonization_of_the_Moon#Advantages [;)]
Advantages
Placing a colony on a natural body would provide an ample source of material for construction and other uses, including shielding from radiation. The energy required to send objects from the Moon to space is much less than from Earth to space. This could allow the Moon to serve as a construction site or fueling station for spacecraft[citation needed]. Some proposals include using electric acceleration devices (Mass driver) to propel objects off the Moon without building rockets. Others have proposed momentum exchange tethers(see below). Furthermore, the Moon does have some gravity, which, experience to date indicates, may be vital for longterm human health[citation needed]. Whether the Moon's gravity (roughly one sixth of Earth's) is adequate for this purpose remains to be seen.
In addition, the Moon is the closest large body in the solar system to Earth. While some Earth-crosser asteroids occasionally pass closer, the Moon's distance is consistently within a small range close to 384,400 km. This proximity has several benefits:
* The energy required to send objects from Earth to the Moon is lower than for most other bodies. Earth-crossing asteroids require a somewhat less delta V, but the months of travel required would necessitate a safe habitat for humans. The extra weight would likely more than offset any delta-V savings.
* Transit time is short. The Apollo astronauts made the trip in three days. Other chemical rockets such as would be used for any Moon missions in the next one to two decades at least, would take a similar length of time to make the trip.
* The short transit time would also allow emergency supplies to quickly reach a Moon colony from Earth, or allow a human crew to evacuate relatively quickly from the Moon to Earth in case of emergency. This could be an important consideration when establishing the first human colony.
* The round trip communication delay to Earth is less than three seconds, allowing normal voice and video conversation. The delay for other solar system bodies is minutes or hours; for example, round trip communication time between Earth and Mars ranges from about eight minutes to about forty minutes. This again would be of particular value in an early colony, where life-threatening problems requiring Earth's assistance could occur. (See, for example: Apollo 13)
* On the lunar near side, the Earth appears large and is always visible as an object 60 times brighter than the Moon does on Earth, unlike more distant locations where the earth would be seen merely as a star-like object, much as the planets appear from Earth. As a result, a Lunar colony might feel less remote to humans living there. The Apollo 8 astronauts, when behind the Moon, were the first humans to have no view of the Earth.
* A lunar base would provide an excellent site for any kind of observatory[citation needed]. As the Moon's rotation is so slow, visible light observatories could perform observations for days at a time. It is possible to maintain near-constant observations on a specific target with a string of such observatories spanning the circumference of the Moon. Radio observatories could be considerably larger than the Arecibo radio observatory, due to the Moon's low gravity[citation needed]. The fact that the Moon is geologically inactive along with the lack of widespread human activity result in a remarkable lack of mechanical disturbance, making it far easier to set up interferometric telescopes on the lunar surface, even at relatively higher frequencies such as visible light[citation needed].
* Perhaps most importantly, from a psychological point of view, the Moon is the only solid body in the Solar System that is visible as a disk with the naked eye from Earth. The ability to look up at the Moon and contemplate on other humans living their lives somewhere other than Earth would be a constant reminder that Earth need not be the only location for humans to live. Psychologically, it would be an important "first step" in colonizing other parts of our solar system.