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Water Found Deep Inside the Moon

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Re: Water Found Deep Inside the Moon

#231

Post by hossbeast »

cpeterso wrote: post #162
athenot wrote: post #34

Earlier quoted context omitted.

When the topic of Backup for Civilization comes up, instead of Wall-E, I tend to think of Elysium, i.e. the backup option is only for the wealthy, leaving the rest in a worse state. https://www.space.com/22287-elysium-space-station-science-na...

For another take on backing on human civilization, check out Neal Stephenson's novel Seveneves . Humanity evacuates 1500 people to orbit as moon debris decimates all remaining life on the earth's surface. As a story, it's pretty dry, but as a thought experiment, it's very interesting. https://en.wikipedia.org/wiki/Seveneves

I was totally engaged by Seveneves, right up until the time jump, at which point I completely lost interest. The hard rain stuff at the beginning is totally fascinating.

Re: Water Found Deep Inside the Moon

#232

Post by hossbeast »

keenerd wrote: post #75
Obi_Juan_Kenobi wrote: post #69

Earlier quoted context omitted.

Mars has atmosphere for aerobraking and ISRU possibilities that the moon does not. In many ways, it is much more practical from a spaceflight standpoint. That's not to say that there aren't possibilities for both, but Mars is seen as the preferred choice for a variety of sound reasons.

The Martian atmosphere is next to worthless for aerobraking human-scale infrastructure. One of the most significant points in the Moon's favor is the (relative) ease with which a space elevator could be built. It doesn't need unobtainium, current structural materials are strong enough.

The same can be said of a space elevator around Mars too, of course. (Though not the earth).

Re: Water Found Deep Inside the Moon

#233

Post by hnlmorg »

pcmaffey wrote: post #228
hnlmorg wrote: post #165

Earlier quoted context omitted.

I know the risks are astronomical (literally), but anything significant enough to alter Earth's mass would also alter the moons orbit. I just think if we are talking about an extraterrestrial base for the sake of "backing up" the human race then it is prudent to pick a location that isn't in any way dependant on the master copy. However I appreciate other concerns also take priority as well (cost, practicality, etc)…

What's the point of a backup though if you can't restore?

I'm not sure I understand your point. Are you implying we shouldn't be backing up the human race because "what's the point if Earth is destroyed?"

Re: Water Found Deep Inside the Moon

#234

Post by boznz »

escape_goat wrote: post #183
sunflowerfly wrote: post #178

Earlier quoted context omitted.

For me the real advantage of a moon base first is safety. If something goes horribly wrong while we are learning to live on other planets, a return to earth or a rescue mission takes far less time. I am not a space expert though, so perhaps this is wrong?

I have head that moon dust is reputed to be a consideration, as it creates a type of environmental problem that would not be as extensive a problem on Mars. My understanding is that, due to a lack of fluid and chemical erosion, it tends to be extremely fine and abrasive, and it clings to everything due to static charge, making it hard to keep out of compartments and machinery. They're both definitely too far for a re…

melt sand it turns into smooth glass, wondering if you couldnt do something similar with a few focused mirrors

Re: Water Found Deep Inside the Moon

#235

Post by seer »

munificent wrote: post #25
tambourine_man wrote: post #7

I've always been more excited about a Moon colony than a Mars one. I mean, compared to Mars, the Moon is ridiculously close. Many of the same benefits Musk seeks (backup for Civilization, excitement) for a fraction of the cost. Low gravity and atmosphere on a dome would be more complicated, but again, compared to Mars, it's right there . It would be a more humble and realistic first step, IMO.

People way underestimate how far away Mars is. To give you a sense of scale, the settlers of Jamestown came from London. As the crow flies, that's about 3,790 miles. If we treat that as equivalent to settling on Mars, then for them to settle on "the moon" would have been a mere 26 miles from London. Perhaps Canvey Island on the River Thames. If we can't manage settlements that close, we really aren't ready yet for th…

Maybe the distance itself is why people are so excited about Mars. When you go to the Moon, human civilization is right there and can interfere with whatever you may wish to accomplish, while on mars it seems so far away that earthly powers will be hard pressed to keep control, but not far enough as to be unfeasible to go to. You can start something new, something your that's your own. It's like the difference between going to Ireland and going to America. Or at least it evokes those kinds of emotions. Truth is you'll be so reliant on Earth in both Mars and the Moon for several generations as to make this distinction moot, but humans are more emotional than rational in nature.

Re: Water Found Deep Inside the Moon

#236

Post by danielbarla »

nine_k wrote: post #214
computerex wrote: post #212

Earlier quoted context omitted.

The space elevator even on Earth in GEO is a hopeless, fool's dream.

On Earth, it's hard to build due to much higher gravity, higher required orbit, and the atmosphere. Getting much shorter lengths of much less strong fiber to Moon may be more realistic than 20.000 km of super strong carbon fiber to GEO.

I'm not too clued up on the topic, but I was under the impression that a lunar elevator would potentially require much longer cables than on Earth (primarily due to the lack of spin of the moon). From the Wikipedia article [1]

> There are two points in space where an elevator's docking port could maintain a stable, lunar-synchronous position: the Earth-Moon Lagrange points L1 and L2. L1 is 56,000 km away from the Earth-facing side of the Moon, (at the lunar equator) and L2 is 67,000 km from the center of the Moon's far side, in the exact opposite direction

> Both of these positions are substantially farther up than the 36,000 km from Earth to geostationary orbit. Furthermore, the weight of the limb of the cable system extending down to the Moon would have to be balanced by the cable extending further up, and the Moon's slow rotation means the upper limb would have to be much longer than for an Earth-based system, or be topped by a much more massive counterweight. To suspend a kilogram of cable or payload just above the surface of the Moon would require 1,000 kg of counterweight, 26,000 km beyond L1.

So, we're talking an ~80,000 km one?

[1] https://en.wikipedia.org/wiki/Lunar_space_elevator

Re: Water Found Deep Inside the Moon

#237

Post by aedron »

hossbeast wrote: post #231
cpeterso wrote: post #162

Earlier quoted context omitted.

For another take on backing on human civilization, check out Neal Stephenson's novel Seveneves . Humanity evacuates 1500 people to orbit as moon debris decimates all remaining life on the earth's surface. As a story, it's pretty dry, but as a thought experiment, it's very interesting. https://en.wikipedia.org/wiki/Seveneves

I was totally engaged by Seveneves, right up until the time jump, at which point I completely lost interest. The hard rain stuff at the beginning is totally fascinating.

Same experience. It was like it was written by two different authors (one fantastic and one awful).

Re: Water Found Deep Inside the Moon

#239

Post by dredmorbius »

flashdance wrote: post #209
Mtinie wrote: post #196

Earlier quoted context omitted.

Without a magnetosphere isn't solar radiation a problem, long-term on the Moon?

Fun fact incoming: there is a mini-magnetosphere centered around Mare Crisium on the Moon. http://onlinelibrary.wiley.com/doi/10.1029/2009GL041721/abst... It's only 360km across though...

TMA-1. Erm, CMA-1.
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