life on the moon?

[jackdavinci]

Could life survive on the moon? Some related questions:

1) The moon is fairly big for a satellite and if the impact origin theory is correct shouldn't it have a similar make up to Earth? So why does it look so different? Is it just below the size threshhold to sustain water and/or atmosphere or is there some other reason? It's in the same orbit as Earth so it can't be temperature/distance fromthe sun. What is the size threshhold or other requirements for having an atmosphere and water? Does the size make it impossible to terraform?

2) I know we have rocks from Mars that have somehow made their way to Earth. How much interchange of materials is there between Earth and the moon? If both were the same size and same basic composition, would the development of life on the Earth pretty much guaranteed life on the moon due to random bits flying off now and then? Would anything bigger than bacteria survive the transition?

3) Is life on the moon possible now? Is there any extreme native Earth species (I assume only bacteria could make it) that could survive on the moon? How about genetically engineered? There's sunlight, so there's a source of energy. It doesn't seem like there's enough surface volcanic material to support hydrothermal type life that we have on Earth. Lack of atmosphere and water would be a problem. Is there any frozen water or oxygen rich dust on the moon? What about other life sustaining materials? Atmosphere I suppose we could deal with by having some sort of material exchanging plants with their own gas bags. What would be the biggest obstacles?

4) What about self replicating machines? Assuming we had the engineering skills to make simple self replicating robots, are there the proper raw materials on the moon to sustain them? I guess there is a little more leeway in basic structural materials, but electronic components require rarer materials right?

[Telemark]

Originally Posted by jackdavinci

1) The moon is fairly big for a satellite and if the impact origin theory is correct shouldn't it have a similar make up to Earth?

IIRC, the moon is made up of the same materials that are in the earth's mantle, not the core. So there's no iron core, no plate tectonics, no volcanism, etc.

[Cervaise]

Originally Posted by jackdavinci

Is there any extreme native Earth species (I assume only bacteria could make it) that could survive on the moon?

Not only could, but did.

[Stranger On A Train]

1. The Moon is a little more than 1% the mass of the Earth, significantly less dense (with a gravity field that is about 18% of Earth), no appreciable surface water, no iron core, and no protective magnetic field. The current tidal lock on the Earth--which probably started several billion years ago--gives it a day/night cycle of slighly more than 27 Earth days where it cycles from blazing hot to life-killing cold. It is, in short, a most inhospitable place for life to develop or sustain. Terraforming--as much as sci-fi authors and speculators like to talk about it in simple terms--is vastly beyond our capabilities. Think of trying to make Antarctica airable for domestic crops, and then imaging a task many orders of magnitude more difficult.
2. We get ejecta from Lunar impacts on occasion (likely much more regularly in the early days of the Solar System). Material going the other way is much more unlikely; aside from difference in escape speed (11.2 km/s for the Earth versus 2.4 km/s for the Moon) there's also the atmosphere that any Earth-borne ejecta would have to punch through. It's possible bacteria floating in the upper atmosphere could be ejected into space, but between the unmitigated radiation environment and the vacuum it's seriously unlikely it could survive such a migration.
3. There is no appreciable surface water on the Moon. Every form of life--even those in deserts--requires water as a "universal" polar solvent. Aside from that, the previously mentioned lack of protections and long day/night cycle make it essentially impossible for any natural photosynthetic life to survive. There is exactly no volcanic activity on the Moon, which as far as we can tell is geothermally inactive.
4. "Von Newmann"-type universal replicators are well into the realm of science fiction, and it'll be decades if not centuries before such a concept is even viable. (Simple nanotechnology automatons which perform a limited set of processing steps are within reach, but this is as far from self-replication as a pogo stick is from a nuclear rocket.) If we did have some technology, it seems not infeasible that we could make them function on the surface of the Moon. There are plenty of raw materials in the regolith, especially if you can seperate elements out at the atomic level. There is also plenty of unfettered sunlight for photovoltaic cells to use for energy.

Stranger