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A newly discovered moon tunnel

washingtonpost.com

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Re: A newly discovered moon tunnel

#61

Post by JumpCrisscross »

samstave wrote: post #37
kurthr wrote: post #29

Earlier quoted context omitted.

The same place that water came from on Earth... comet impacts and residual moisture from the impact that split the Earth-Moon system. Really the same place all planetary water and gas has come from. There's not much left because it mostly boils off due to low pressure, but in dark crevasses it's likely to stay cold enough to remain condensed. It's been measured spectroscopically.

Where did the comets get the water they impacted on earth?

> Where did the comets get the water they impacted on earth?

Hydrogen comes from primordial nucleosynthesis [1] and makes up most of the interstellar medium [2]. Oxygen is produced when neutron stars collide and stars explode [3] as well as when some stars burn [4]. These freely combined in the gas disk from which our solar system formed, condensing into planets, moons, comets and other things [5].

[1] https://en.m.wikipedia.org/wiki/Big_Bang_nucleosynthesis

[2] http://casswww.ucsd.edu/archive/public/tutorial/ISM.html

[3] https://www.chemistryworld.com/news/heavy-elements-forged-by...

[4] https://en.m.wikipedia.org/wiki/Oxygen-burning_process

[5] https://www.lpi.usra.edu/books/MESSII/9028.pdf

Re: A newly discovered moon tunnel

#62

Post by cyberferret »

sideshowb wrote: post #57

"Let's dig a tunnel to the centre of the moon!" "You can't dig a tunnel to the centre of the moon, Blode!" "Yes I can! It will be a special tunnel, and it will go to the centre of the moon!" Anyone else remember that?

I don't recall that quip, but I do recall an episode of "Space 1999" decades ago titled "The Catacombs of the Moon" where they discover a vast underground cave system, (which turns out to be the hibernation place for a civilisation of aliens, IIRC)... The episode always had me intrigued as to whether the moon actually could have a large cave system that could be hermetically sealed and inhabited by humans to save on shipping tons of building materials out there.

Re: A newly discovered moon tunnel

#63

Post by vorticalbox »

sdenton4 wrote: post #52
lostlogin wrote: post #42

Earlier quoted context omitted.

But there isn’t exactly a lot of readily available resources on the moon, so until that changes your just paying to lift stuff twice. Water may be an exception to this?

You can use electricity to split water into hydrogen and oxygen, aka, fuel. Finding an underground ice lake would provide lots of fuel, and save on lifting the heaviest, most important substance for manned exploration from earth.

Water takes a lot of energy to split. Take a small size as a pot on a cooker with a litre of water.

Just to get that litre to bubble takes constant. Heating for minutes or imagine how long it would take to boil all that water away.

Sure you'll have a lot of fuel but its not easily accessible.

Re: A newly discovered moon tunnel

#64

Post by kurthr »

samstave wrote: post #54
gjjrfcbugxbhf wrote: post #45

Earlier quoted context omitted.

Water is just hydrogen plus oxygen. Both are fairly common elements in the universe.

Under what circumstances does one need to have in order to make them combine into water, organically? (Meaning without any device or machine, assume you have two big clouds of each element floating in space - if they collide, do the naturally just form into water molecules?)

At reasonable temperatures, yes, the clouds turn into water and release energy, hydrogen burns. Water is entropically preferred as a lower energy state than separate atoms/molecules because of lower enthalpy at reasonable temperatures. Depending on density and ignition sources the reaction rate may vary, but it doesn't have to explode in a ms when there is a billion years available.

Re: A newly discovered moon tunnel

#65

Post by ealloc »

kurthr wrote: post #29
samstave wrote: post #19

Earlier quoted context omitted.

If the moon had ancient volcanic activity and thus, why is it, after observable impact from various bodies - shown in the craters all over the surface, and the sumizing of the fact that water was deposited to earth from extra-orbital impacts... does the moon have zero water or atmosphere? Where did water originate? (I didn't know how to format that question any better, so please forgive the fumbly format)

The same place that water came from on Earth... comet impacts and residual moisture from the impact that split the Earth-Moon system. Really the same place all planetary water and gas has come from. There's not much left because it mostly boils off due to low pressure, but in dark crevasses it's likely to stay cold enough to remain condensed. It's been measured spectroscopically.

The reason water exists on earth, and not on mars, may be that life on earth saved the water by discovering photosynthesis.

The discovery of photosynthesis caused the "great oxygenation event" which pumped oxygen into the atmosphere. Oxygen reacts with atmospheric hydrogen to form water. Without the oxygen, the very light hydrogen molecules would float to the top of the atmosphere and are easily blown away by solar winds, which is what happened on Mars. But with high oxygen concentrations on Eath, hydrogen molecules react to form heavier water molecules before they have a chance to be blown away, and thus hydrogen and water are retained.

I read about this in the book "Oxygen" by Nick Lane.

Re: A newly discovered moon tunnel

#66

Post by cgb223 »

space_fountain wrote: post #34
space_fountain wrote: post #33

Earlier quoted context omitted.

If you ever want to do a lot in space a ton

Sorry meant to expand more. The fact that the moon has such lower gravity than the earth means it's a lot cheaper in theory to get stuff from the surface of the moon to orbit than from earth

How much energy does it take to get stuff from the earth to the moon though?

Is it that much less than leaving earths gravity all together?

Re: A newly discovered moon tunnel

#67

Post by pjungwir »

JumpCrisscross wrote: post #61
samstave wrote: post #37

Earlier quoted context omitted.

Where did the comets get the water they impacted on earth?

> Where did the comets get the water they impacted on earth? Hydrogen comes from primordial nucleosynthesis [1] and makes up most of the interstellar medium [2]. Oxygen is produced when neutron stars collide and stars explode [3] as well as when some stars burn [4]. These freely combined in the gas disk from which our solar system formed, condensing into planets, moons, comets and other things [5]. [1] https://en.m.w…

Thank you for this answer! But then why does the water have to come from comets? Why couldn't the Earth have formed with its own water?

Also, we seem to have a lot of water. It's really all from comets, a little here, a little there?

Re: A newly discovered moon tunnel

#68

Post by kirillkh »

spdustin wrote: post #60
samstave wrote: post #19

Earlier quoted context omitted.

If the moon had ancient volcanic activity and thus, why is it, after observable impact from various bodies - shown in the craters all over the surface, and the sumizing of the fact that water was deposited to earth from extra-orbital impacts... does the moon have zero water or atmosphere? Where did water originate? (I didn't know how to format that question any better, so please forgive the fumbly format)

The moon's core isn't made of the swirling molten iron dynamo like Earth's is. No swirling molten iron, no magnetic field. No magnetic field, nothing deflects the solar wind that then, literally, blows away any fledgling atmosphere. It's believed that Mars' atmosphere was considerably more dense than it is today, but along the way, its core cooled, and it lost its protective magnetic shield, allowing the solar wind t…

Then we have no hope of ever engineering Mars to have enough air for us to breath?

Re: A newly discovered moon tunnel

#69

Post by Nition »

sideshowb wrote: post #57

"Let's dig a tunnel to the centre of the moon!" "You can't dig a tunnel to the centre of the moon, Blode!" "Yes I can! It will be a special tunnel, and it will go to the centre of the moon!" Anyone else remember that?

The Internet in its infinite wisdom tells me this is from "Tales of the Blode Episode 2: A Trip to the Seaside."

Re: A newly discovered moon tunnel

#70

Post by II2II »

Density wrote: post #44
pavement wrote: post #35

Earlier quoted context omitted.

Whoever gets there first, and can realistically form a threat credible enough to defend it. You’ll probably need the backing of a nuclear power, although off-world representation of earthly countries might not turn out to be particularly credible threats (enough to intimidate new emerging space-based powers), or remain truly politically cohesive with their root terrestrial counterparts, depending...

I have the sinking feeling we'll be teaching space marksmanship to our next batch of astronauts.

If it came to blows, chances are that the battles would be fought on Earth. Launching anything is expensive. Launching anything manned is prohibitively expensive. Armaments would just increase the cost and the risk.
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