Moon Water Discovery Hints at Mystery Source Deep Underground | Hacker News Reader

Moon Water Discovery Hints at Mystery Source Deep Underground

space.com

74 pointspeterkelly31 comments

With the presence of (liquid) water, is there a high chance of simple alien life on the moon? I mean, i can't think of any place in the sea that's downright hostile to life, where life hasn't found a way™.

This isn't about liquid water, as far as I can tell.

I remember when the search for water meant something big. I remember the media being all over it.

Now, there is water everywhere and nobody cares.

Actually this is just a confirmation of water already previously found. It's nothing super groundbreaking but very significant nevertheless.

It's also the fact that the moon isn't exotic enough for the media/masses.

Confirming a significant amount of water on the moon could mean in-space fuel manufacturing and refueling, though!

How? Water is already a relativly low-energy compound, so I assume you are talking about using it to manufacture hydrogen molecules to use as fuel.

An external source of water is completely unnecessary for this. The idea behind hydrogen as a fuel is that you can react it with oxygen to produce water, which is a lower energy molecule. You can then harness that difference in energy to do whatever. The amount of water generated is equal to the amount of water needed to generate the hydrogen (and oxygen) molecules in the first place. It is a rechargable battery.

I think the idea is that you can use solar or nuclear to crack it into hydrogen and oxygen for use as rocket fuel. With rockets, fuel is both energy source and reaction mass, meaning that you throw it out the back end and can't recover it. You can also use the oxygen for breathable atmosphere. Every kilogram of useful mass you can find on the moon is one less kilo you have to haul from earth.

You can also use it as propellant for nuclear thermal rockets. You can't lift off from Earth on one, but the Moon is an easier problem.

Terrestrially you are correct, but space is a very different situation. There you can get plenty of energy, but volatiles are rare.

H is needed for water (for people) and propellant (for rockets). The rockets in particular are open systems and must be, so need a plentiful supply. If you can find a good source of Xenon, you can use that in some applications instead, but that's probably harder than H since it doesnt form more stable materials like H2O.

Yep. We're pretty good at making engines that run on hydrogen and oxygen, but we don't have a way of getting those things in sufficient quantities in space. We do have ways of getting plenty of electricity in space, though...

What would happen if very simple life was found on the moon? I mean what effects would it have on society, would it be as significant if life was found say on mars? Would it put an end to the alien life debate or just fuel it further? I doubt have high hopes for there being life there, as obviously life needs more than just water but its fun to think about

I have debates about evolution with my Christian friends (who believe in the creation story of Adam and Eve) often. Whenever I mention evidence of evolution documented by scientists, they always reference the Bible as evidence of the creation story. That then turns into a debate about the writing processes of peer reviewed scientific papers vs the method of those who wrote the bible. It usually ends with them stating the bible was written by god "himself", so it couldn't be wrong, and me realizing I cant change their minds.

Needles to say, we live in a society where many base there beliefs on blind faith, and those who do are almost impossible to convince of something that goes against their faith. Even if simple life was found on the moon, they wouldn't believe it unless it was the kind of alien life from movies that invades earth with spaceships.

I think a lot would depend on the origin of that life. Asteroid and comet impacts with Earth can eject life bearing material into space, and that material can reach the Moon, Venus, Mars, Jupiter, and beyond [1].

Some life forms seem likely to be able to survive that kind of ejection, and a long trip through space, and re-entry in a planetary atmosphere [2].

If we find life on the Moon, or Mars, or Europa, it could turn out to be that it originated on Earth. It would still be an amazing and extremely interesting discovery, but not the momentous discovery that finding true alien life would be.

When considering the possibility that Earth life has spread to other parts of the solar system, one should also consider the possibility that it went the other way. Just as ejected material from Earth can reach other planets, ejected material from other planets can reach Earth. Some believe that conditions on Mars once were more favorable for the origin of life than they were on Earth, so it is a possibility that life started there, and then spread to Earth. Around 0.2% of meteorites found on Earth are thought to have originated on Mars.

[1] http://arxiv.org/abs/1108.3375

[2] http://www1.univap.br/~spilling/AB/Olsson-francis_cockel_201...

The actual source, "Remote detection of magmatic water in Bullialdus Crater on the Moon":

http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo19...

Am I the only one thinking about underground moon aliens?

yes

Moon Nazis, I watched a documentary about those, "Iron Pie" or something like that...

Iron Sky : http://www.imdb.com/title/tt1034314

I should have used <sarcasm>

I was thinking Little Makers.

http://en.wikipedia.org/wiki/Sandworm_(Dune)

this is about magmatic water, which is stuff trapped underneath the crust in the liquid planetary interior. you'd hardly call the stuff liquid since it's going to manifest itself as hydroxide or other hydrated minerals once released to the surface. just like the polar region solar wind water / hydrogen, you'd have to actually mine the damn stuff in order to make use of it. seeing as rocks have a ton of oxygen in them normally, this is really only significant as a source of hydrogen. permanently shadowed ice "may" be significant as a source of water in and of itself, but even still you've got huge technical challenges trying to get at it (care to operate in a 30K environment).

anyways, mercury has way better ice deposits than the moon does and no one cares.

EDIT: oh yeah the apollo missions found hydrated volcanic glass beads that were ~15ppm water, i'm not sure how this finding relates to that one but don't get the idea that the quantities involved will be large on a local scale though they're probably much higher than that.

Merely getting to orbit Mercury is more energy-expensive than leaving the solar system altogether, then landing in a high-gravity environment and without an atmosphere. Mercury is not easy to get to.

Yes I agree. I did see something very interesting a couple months ago about favorable temperatures in subterranean donuts near the Mercury poles. Regardless, Moon and Mercury are both "high gravity" - L4/L5 or cis-lunar asteroid stations are clearly the way to go. Only things the moon is good for that asteroids aren't better for is He3 and astronomy.

I'm trying to wrap my head around this. Is it really more energy intensive to slow down in mercury's orbit, than escaping the sun's gravity well? If that's true, can I inflect that the delta between mercury and earth is larger than the delta between earth and infinity, i.e. we are 'more than halfway out' of sun's gravity well in terms of gravitational energy levels?

Yes. Check the orbital velocities involved. Mercury is 48 km/sec, Earth is 30, and an object at infinity would be zero. Kinetic energy is proportional to velocity squared. Square the orbital velocities and you see the Mercury-Earth energy delta is larger than Earth-infinity.

Thanks. Makes sense of course.

No surprise here. The most popular hypothesis of Moon formation says, that it used to be a piece of Earth (https://en.wikipedia.org/wiki/Giant_impact_hypothesis).

That has got to be hands down the the most horrible site for browsing on an iPhone I have ever seen. It's almost completely unreadable. It's like being stabbed in the eyes with sharpened social media icons. (OT for article, but not HN).

There's plenty of HackerNews apps you can use rather than the website.

I'm guessing they're referring to the space.com site. When zoomed in on the text (Android 4.3), there are FB, G+ etc. share buttons floating in the middle of the screen and the drop down top menu likes to make sporadic appearances also.

I use the Android app of this: http://hn.premii.com

It summarises the content so you don't have to even visit Space.com. Problem solved.

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