Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

A newly discovered moon tunnel

washingtonpost.com

Post reply on HN
Print view View original

111–120 of 188 posts

Re: A newly discovered moon tunnel

#111

Post by sfifs »

II2II wrote: post #70
Density wrote: post #44

Earlier quoted context omitted.

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.

Launching a rock back at earth would probably be quite cheap given you need to have propellents on hand to be there in the first place. So at some point of habitation, moon based folks will bid for Independence.

Re: A newly discovered moon tunnel

#112

Post by [deleted] »

DougWebb wrote: post #103
yeukhon wrote: post #99

Earlier quoted context omitted.

Though a jewelry made from Moon elements would probably have a ten-fold price tag than the Earth’s counterpart, because it’s from the Moon.

Maybe at first, but not once they're mass-produced on the kind of scale that would be needed to justify the cost of moon-based mining.

[deleted]

Re: A newly discovered moon tunnel

#113

Post by IncRnd »

dangpzanco wrote: post #5
kharms wrote: post #2

When such discoveries are made who "owns" that real estate?

"Who Owns the Moon? | Space Law & Outer Space Treaties" - https://www.space.com/33440-space-law.html

Treaties on Earth have very little meaning. They have zero meaning on the Moon.

Re: A newly discovered moon tunnel

#114

Post by joshuahedlund »

DougWebb wrote: post #73
ealloc wrote: post #65

Earlier quoted context omitted.

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 w…

That seems like it must be incorrect. Life on earth evolved in the oceans, so the oceans had to exist for eons before life evolved and the eons it took for life to evolve photosynthesis and produce significant amounts of oxygen in the atmosphere. If what you're saying is correct, then the earth either started out with much more water than it has now, or the hydrogen escaped a lot more slowly than I'd expect it to.

> Life on earth evolved in the oceans, so the oceans had to exist for eons before life evolved

I can't intelligently contribute to the overall discussion here, but I know one of the most interesting things about the currently understood timeline is the apparent lack of eons between the earliest conditions conducive to life after its initial cooling and the earliest evidence of life. Don't quote me on exact numbers, but within margins of error, as I understand it, it's like in the range of millions of years, not billions (which has all sorts of interesting implications for both the Fermi paradox and religious thinkers) Though, as far as I know, you'd still be correct on the distance to photosynthesis.

Re: A newly discovered moon tunnel

#115

Post by waegawegawe »

larkeith wrote: post #86
waegawegawe wrote: post #77

Earlier quoted context omitted.

That said, the earth's atmosphere has a mass of about five billion billion tons. For reference, as a species, we produce about ten billion tons of concrete each year. This is just to give a sense to the scale of effort involved in replacing a planetary atmosphere.

Depending on the volume of surface ice (especially at the poles), might it be possible to produce atmosphere on a massive scale via orbital lenses or mirrors? With recent advances in solar sail technology, I can't imagine the implementation would be too far removed from current capabilities.

Think about how large of a lens you're talking about. Even if it were one hundred meters across and was able to collect 100% of the sun's energy passing through it, the amount of energy produced would be utterly insignificant compared to the problem we're discussing. And how would you get a one hundred meter lens to mars orbit? Even after that, you have to consider that we want an oxygen atmosphere, not one made of water vapors.

I don't know what you mean by "too far removed from current capabilities", but I doubt we'll even start working on the problem for two or three centuries.

No, it seems more likely to me that we'd use our growing knowledge of genetics and psychology to hack out the part of ourselves that needs to be outside, and opt for a purely enclosed existence on Mars.

Re: A newly discovered moon tunnel

#116

Post by hutzlibu »

larkeith wrote: post #86
waegawegawe wrote: post #77

Earlier quoted context omitted.

That said, the earth's atmosphere has a mass of about five billion billion tons. For reference, as a species, we produce about ten billion tons of concrete each year. This is just to give a sense to the scale of effort involved in replacing a planetary atmosphere.

Depending on the volume of surface ice (especially at the poles), might it be possible to produce atmosphere on a massive scale via orbital lenses or mirrors? With recent advances in solar sail technology, I can't imagine the implementation would be too far removed from current capabilities.

With lenses you could also burn the soil to produce gases that add up to he atmosphere ... but we want breathable atmosphere. With lot's of oxygen and very little co2. And that is a bit harder ...

So you also couldn't just vaporize the ice, you need to split it up. Solar heat could be sufficient, but the water will then be missed everywhere else on mars where life wants to grow.

And Mars is dry.

So I would first use the water in enclosed habitats. And then after, if there is plenty of water left, one could start to think about smoking that up ..

But there might be other options, once you have lot's and lot's of autonomous machines and rockets available and allmost unlimited fuel (sun?). But without that? Not a chance ...

Re: A newly discovered moon tunnel

#117

Post by Turing_Machine »

samstave wrote: post #100
lrdd wrote: post #95

Earlier quoted context omitted.

I think the short answer is we don't really know, but the simplest explanation is muddy icy comets colliding

If that's the case, why haven't we been hit by any in recorded history that gave us more water? How many comets have hit us that were rife with water supplies to provide the amount of water earth has given that water isn't also abundant on planets that are much larger, like Jupiter? Why do we see planets with atmospheres of say sulfer, and earth doesn't have an issue with sulfer in the atmosphere?

"If that's the case, why haven't we been hit by any in recorded history that gave us more water?"

Most of the comets whose orbit intersects with Earth's orbit collided eons ago.

Some comets still enter the inner Solar System, of course, but it's going to be extremely rare for one to be on the right path to hit the Earth.

Re: A newly discovered moon tunnel

#118

Post by Turing_Machine »

IncRnd wrote: post #113
dangpzanco wrote: post #5

Earlier quoted context omitted.

"Who Owns the Moon? | Space Law & Outer Space Treaties" - https://www.space.com/33440-space-law.html

Treaties on Earth have very little meaning. They have zero meaning on the Moon.

On the contrary...

https://en.wikipedia.org/wiki/Treaty_of_Tordesillas

Look at that line, and note which non-European countries speak Spanish and which ones speak Portuguese.

For instance, Brazil wound up being Portuguese (a rarity in South America) because it stuck over the line into Portuguese turf.

Re: A newly discovered moon tunnel

#119

Post by devrandomguy »

rbanffy wrote: post #96
moomin wrote: post #3

Sounds like we need to send a probe or ten to the Moon. Who knows what’s down there? (Although the answer is going to be “some rocks” as far as most non-astronomers are concerned.)

Probably ice. Ice that falls into the entrance and then sublimates has a good chance of moving to perpetual darkness regions and to stay there. Factor a couple billion years and you probably will have a decent amount. Now imagine there is some simple biology happening from the time the Moon had some atmosphere, in caves sealed billions of years ago.

The missing back story to Apollo 18!

Re: A newly discovered moon tunnel

#120

Post by hyperpallium »

knappe wrote: post #90
galaxyLogic wrote: post #20

Earlier quoted context omitted.

> no earthquakes No but how about moon-quakes? Ok, not geologically active you say. But moon's been bombarded by asteroids it's surface is full of craters. Creating a crater wouldn't that be an equivalent of a moon-quake?

You're not accounting for tidal forces. The same forces that create the tides on Earth also affect the moon. In this case via moon-quakes. https://phys.org/news/2017-08-moon-tidal-stress-responsible-...

But the moon is one-face, so tidal stress should be constant.
Post reply on HN