Live data from Hacker News

Water Found Deep Inside the Moon

news.nationalgeographic.com

101–110 of 284 posts

Re: Water Found Deep Inside the Moon

#101
I wonder why Elon Musk is so obsessed with Mars. Why not allocate the resources that would be spent on covering that massive distance into colonizing a much closer Moon.

Bonus points because we get to look at it from Earth. Imagine being able to capture the attention of every moon gazer on earth. Google Adwords for Moon!

Re: Water Found Deep Inside the Moon

#102
post #16

Earlier quoted context omitted.

Inasmuch as Mars with our current technology offers no back up for civilization, the same can certainly be said for the moon. I would argue over that the moon actually has some benefits Mars lacks, in addition to proximity it has a much lesser gravitational field and therefore a much lower delta V. Moon colony could realistically jumpstart space and vacuum industries beyond LEO, and frankly it would probably give us…

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.

"Mars' atmosphere is in the perfect goldilocks zone of being a total headache" - https://www.youtube.com/watch?v=h2nqgKL2JQU

Re: Water Found Deep Inside the Moon

#103
post #56
post #36

Earlier quoted context omitted.

In terms of distance, sure. In terms of delta-v, the budget for the moon is upwards of 50% that for Mars. EDIT: The 50% figure is from memory, and upon further reflection is probably not quite right, so take it with a grain of salt. I just wanted to point out that distance is not the only relevant metric.

>The 50% figure is from memory, and upon further reflection is probably not quite right, so take it with a grain of salt. You're actually underestimating. Mars has an atmosphere, so spacecraft can use aerobraking to significantly reduce the delta-v required to get there. The moon has no such benefit — propulsion is required all the way to the surface. The advantage of the moon, of course, is that it's not limited to…

Shared this video[1] about the same topic above[2]

[1] https://www.youtube.com/watch?v=h2nqgKL2JQU [2] https://news.ycombinator.com/item?id=15093353

Re: Water Found Deep Inside the Moon

#104
post #18
post #2

Unrelated to the article, but WOW did anyone else see the giant full view height ad video at the top? I have ad blocker off for NatGeo. It's followed by a giant banner. I can't imagine how much crazier ads have been getting and most of us don't even notice 'cause we have ad blocker.

I just got a new laptop and hadn't got around to installing uBlock yet. I'm comfortable saying the mainstream web is literally unusable without ad blocking. I watched the download notifications in the status bar iterate through dozens of ad servers, for 1-2 minutes, per page. I could barely scroll at all. I couldn't tell where the actual content was. All 3 columns full of ads. You have to hunt for isolated paragraphs…

> a festering petri dish of promiscuous cookie-sharing

Shouldn't that be impossible? What browser lets one site access another's cookies?

Re: Water Found Deep Inside the Moon

#105
post #89

Earlier quoted context omitted.

just like there is water in the most arid deserts on earth ... and still they are a jungle compared to moon and mars. So I think, boone-dry is a quite correct description ...

Adj. 1. bone dry - without a trace of moisture; as dry as a weathered bone

metapher - something not allways meant to be literal in a scientific sense. Bone dry is a very good description for a desert for a ordinary human beeing, as it means you wont find water you can use

Re: Water Found Deep Inside the Moon

#106
post #84

Earlier quoted context omitted.

> the backup option is only for the wealthy, leaving the rest in a worse state. Like most technology, it flows from the rich to the poor eventually as it becomes cheaper. The important part you omitted is that it leaves the rest in a worse relative state. Their absolute state is no worse, and likely better. Arguing against a backup for civilization (or more appropriately, a backup for the species) because it will be…

Why is humanity's survival important?

Because the universe drives towards increased complexity.

Solar fusion creates heavier elements. Gas clouds collapse into stars and planets.

Life, while insignificant on a mass scale, nonetheless represents one of the greatest increases in complexity and diversity the universe has thus far produced.

For that reason alone, it's sacred, and should be cherished.

Re: Water Found Deep Inside the Moon

#107
post #77

Earlier quoted context omitted.

Of course you can, it just takes a few orders of magnitude longer.

If the one specialist in your mission dies and it takes 8 years to send a new one, that's not called an effective replacement.

Has it ever taken 8 years to send something to the moon?

Re: Water Found Deep Inside the Moon

#108
post #42

Earlier quoted context omitted.

Yeah, it does. The real concern is that the moon-day is a full month long and there is no atmosphere transferring heat; any permanent structures on the surface will get very very cold during those two weeks in the dark. If we don't solve this with suitable solar-charged batteries we would need multiple outposts -- say 4 of them dotted around the Moon -- with colonists rotating through the cities to stay in the Sun. B…

Why not poles?

I'm glad you asked! So there's an important physics reason why the equator is warm and the North and South poles are cold on this planet, and it has to do with how you point a surface. If you ever find yourself in a dark office with a bright desk lamp (or maybe your home office or kid's bedroom might be suitable) you might even try this experiment: take a flat surface, a notepad or steno pad, and hold it up facing the light source, then slowly tilt it away and look at the color of the surface; you'll notice that it doesn't sharply transition from illuminated at 0 degrees to dark at 90 degrees -- instead it smoothly varies like the cosine of that angle.

This mathematical effect is incredibly important, it means that sunlight, during the day, averages out to being half as strong as its maximum over the whole of the Earth's surface. The calculation isn't even particularly difficult: the surface area of a sphere is well-known to be 4πr², half of that or 2πr² is illuminated at any one time, but the actual irradiation that we receive is proportional to the cross-section area, which is just the area of the circle: πr². So if the Sun-directly-overhead light were to be illuminating that entire half of the world, we would get k·2πr² light for some k, but instead we only get k·πr² light for that same k, so it works out to be 1/2 when averaged over the whole surface of the Earth.

While I was at university a fellow student asked me to guess the coldest place in the Solar System. I guessed "the middle of the dark side of Mercury." I guessed this for a couple reasons: (1) I knew I needed a rock without an atmosphere since atmospheres sustain convection currents that transmit energy, and (2) I figured since Mercury is so close to the Sun it's probably tidally locked to the Sun and therefore this part probably has not seen a speck of sunlight in millions of years.

It turns out that general relativity makes point #2 wrong and my friend gleefully informed me that he was looking at an article (there were many, so let's take [1] as representative) suggesting that it might be in a crater on the South pole of the Moon. This has basically the same reasoning of (1) and (2) above, except substituting the shadow of a crater for the shadow of tidal locking. But Mercury is still in the running -- the only issue is that we might not be looking at the dark side of it, but rather, again, at its poles.

[1] https://www.space.com/7311-moon-craters-coldest-place-solar-...

Re: Water Found Deep Inside the Moon

#110
post #2

Unrelated to the article, but WOW did anyone else see the giant full view height ad video at the top? I have ad blocker off for NatGeo. It's followed by a giant banner. I can't imagine how much crazier ads have been getting and most of us don't even notice 'cause we have ad blocker.

They are aggressive with ads because everyone is using ad blocker and no one clicks on ads. Content and infrastructure are not free. What do people expect to happen??
Post reply on HN