Hacker News new | comments | show | ask | jobs | submit login
Abundant water likely to exist under ‘moon rabbit,’ Japanese research team says (japantimes.co.jp)
101 points by pmoriarty 7 months ago | hide | past | web | favorite | 70 comments

As I have been growing up and reading about space exploration the narrative had been same: the Earth is special because it has water which allows it to have life. Today it seems like the latest technologies allows us to discover that water in some form is everywhere we look. I believe that it will be the same with life. Today the only known form of life is on Earth and I can’t wait to read about all the discoveries of different forms of life on other planets...

The distinction between (liquid) water and ice is pretty significant for astrobiology. I feel more like we are very quickly reaching the point where we have established that our solar system is barren of any (macroscopic) life[1]. And while we might be able to detect existence of life on other systems (by some chemical signatures), I very much doubt that we are going to see any more direct discoveries of extraterrestrial life during our lifetime simply due the vast interstellar distances involved.

[1] Sure, even micro-organisms would be a major discovery, but ultimately imho of limited interest and impact.

The difference between nothing and micro-organisms is much greater than the difference between micro-organisms and macro-organisms. The discovery of non-terrestrial-origin micro-organisms in our solar system would be massively significant.

Going from no life to simple life might actually be much easier than going from simple life to complex life.

According to Nick Lane in The Vital Question: https://en.wikipedia.org/wiki/The_Vital_Question

Really enjoyed that book, and tend to agree, but it would still be pretty amazing to find microbes somewhere else....

> it would still be pretty amazing to find microbes somewhere else....

We already know two things with certainty:

- a very small amount of material transits between Earth and Mars.

- all material on Earth contains microbes.

It would seem we also know that there are microbes on Mars, though at insignificant levels and likely not flourishing.

I thought meteorite transfer was one-way... Mars to Earth.

Why? It seems to me the requirement is to have a mass with escape velocity from the parent body, and then have it’s orbit intercept another. The delta v required for the latter is symmetrical, from mars to earth. Hence, if a rock reaches escape velocity it would seem to me to be as easy to have pieces of earth rain on mars as it is to have mars fragments rain on earth. The impact on earth to cause ejecta to have escape velocity would probably need to be larger than on mars.

The dV to get off Mars and to interplanetary transfer is about half that from Earth. I would expect the ejection energy of impact debris particles to scale with the square root of the impact energy, so you'd need four times the impact energy on Earth to achieve the same level of debris ejection as on Mars, and that's not counting the effect of Earth's atmosphere on cushioning and ameliorating such impacts.

The dV to then end up on either planet doesn't matter because aerobraking and lithobraking do all the work for you.

> The impact on earth to cause ejecta to have escape velocity would probably need to be larger than on mars.

significantly larger, because it has to get through our atmosphere once on the way in, and then the ejecta has to do it again on the way out, keeping in mind that drag is proportional to velocity squared, and that whatever ejecta is making this trip has to find a way not to get cooked into sterility by impact energy or friction with the air....

Too many extra factors are in play, each of which adds an exponent to the unlikelihood. But that's just my uneducated opinion, I'm certainly open to discussion.

Why? Earth gets hit by large meteors just like Mars does.

What is it about going from nothing to micro-organisms that is so much more interesting than from micro-organisms to macro-organisms?

The other answers here so far are philosophical, I'll give you one that's scientific. Most of the biochemistry of life is required just to have life at all. The incremental increases in complexity of the biochemistry for complex or multi-cellular life is relatively modest. Therefore you get most of the bang for your biochemical buck just by having life at all.

Because it poses new interesting questions: If extra-terrestrial life exists, do we have a common ancestor? This is the theory of panspermia. Or does life spontaneously arise when conditions are right, but with variation?

It would be particularly exciting to discover life that is similar to Earth but with an opposite chirality, or a genetic code that encodes amino acids using different base pairs.

I am willing to bet that whatever is eventually found will be remarkably similar to what we are familiar with on Earth, assuming a liquid-water environment, and the constraints that implies. Single-celled life appears to have arisen so rapidly that it predates the end of the Late Heavy Bombardment, after all.

(I'd be thrilled to be wrong about this, of course, just as I would be fascinated with any xenobiological discovery at all. But I do think the 'endless forms most beautiful' are also strongly constrained by simple physics, and thus the solutions found by an evolutionary random walk will resemble what we already know.)

This is what I suspect with microorganisms as well. Macroorganisms are much more complex and they have common features that seem very arbitrary like moving via cylindrical appendages called legs, or having faces that feature 2 eyes, a nose, and a mouth. It makes me think that it's much more likely to see something wildly different between macroorganisms on Earth and elsewhere than between microorganisms. It would be cool to see other forms of movement, other forms senses, other forms of communication, other forms of anatomy, etc.

EDIT: It also makes me wonder how different an ecosystem could be. Imagine one that did not require macroorganisms eating other macroorganisms, like ones that feed on heat or wind.

EDIT 2: Maybe mating requires 3 genders, etc. There seems to be a lot of room for variation.

There's even wild differences between macroorganisms on Earth.

Invertebrates are much more relaxed about number of eyes etc.

We can go from "humans are the optimal form!", to "well, some kind of mammal", "c'mon, it's got to be a vertebrate", then get into the Cambrian experiment, go back further to different DNA (RNA anyone), then to different metabolic pathways, then to different organic biochemistry, then to non-carbon... and why should life have a chemical basis, anyway? So chemocentric.

How can we tell when he go from too anthropocentric to too anti-anthropocentric? We have guesswork only. We're like a child rebelling against its parents.

It seems to me, that elephants, dolphins, parrots, octipuses, and even spiders could have undergone the rapid brain-size increase that happened to some apes. (We don't even know why it happened to us.) They might still do so, in a few million years.

On the other hand, some physical features have evolved multiple times independently. The eye is one key example. IMO this is a strong indication that creatures that evolved in places other than Earth probably also have something we'd recognize as eyes.

Yes, a great procedure for getting parameters.

Note that some earth creatures - deep sea and underground - have almost lost eyes. Like [blind mole rats](https://wikipedia.org/wiki/Spalax). They have appropriately alien-like nose-antennae.

If there's light, they'll have eyes. Probably.

The rapid emergence of single-celled life on Earth is not necessarily evidence that it was an easy step for evolution. See the discussion surrounding “conditional on success, all the hard steps, no matter how hard, take about the same time” in this article: http://mason.gmu.edu/~rhanson/greatfilter.html

Because it would be a proof positive that life isn't so absurdly infrequent/hard to create as it seems right now.

Yep that was what I meant.

because it's definitive proof that we aren't alone.

A lot of scientists are headed in the other direction: the discovery that planets are common, and that there are a couple of places in the Solar system which have liquid water up against rock make it more likely that extra-terrestrial life exists, even in our own solar system.

The special thing about water on Earth is that it's liquid and has been for a very long time.

Just wait until detailed data on Earth-sized exoplanets comes in. That might not be very special at all. We just don't know yet.

and on the surface

That might not be that important? It was most of a billion years between when life arose on Earth and when life figured out photosynthesis so you can get a long way with just chemosynthesis.

Sunlight, gas exchange, weather and lighting might be very important, but it's hard to know. There are many theories regarding which types of abiogenesis are possible so the required circumstances are unknown.

If we only had a good definition of what life is. The border between organic and inorganic gets kinda blurry with time.

I don’t think we’ll ever hear about other life forms nor will they hear about us. It looks like the time between a society building advanced technology and it self-destructing from overuse of that technology may be only a very small window. I don’t think humans will go extinct, but there will certainly be a mass wipeout where only the most “primitive” aboriginals remain.

Either that or we reach the Singularity, and if that's the case in most civilizations, then maybe we should be searching for AIs

>As I have been growing up and reading about space exploration the narrative had been same: the Earth is special because it has water which allows it to have life.

My pet theory is that microscopic life is relatively common but complex life, let alone intelligent life, is exceedingly rare.

It'll be fun to learn about shared consciousness, archetypes, etc. If any.

Edit: I'm guessing downvoters are low-openness types. But this is a speculative discussion, _that's the point_. In particular this is a question of the level of universality of what we on Earth consider universally-human principles, but we see consciousness outside of humanity as well. So where does it stop?

All speculation isn't equal. There's a difference between informed speculation ("Based on my expertise, I think it's likely X will happen"), philosophical speculation ("What if X happened? Well, here are some obvious consequences…") and idle speculation ("Duuude, what if 'woof' is just dog-language for 'moo'?"). I think people probably didn't see anything to take away from your comment, and that's why they're downvoting, not because their minds are closed to speculation.

Hmm, that's a pretty serious writeup about types of speculation for something that isn't exactly off the wall here. If people thought, "there's no takeaway here" and then downvoted, as you said, that goes against the spirit of open-minded discussion. They should simply ask more questions or go find something to upvote.

If there exist other life forms with consciousness, the question of whether they share consciousness in the form of shared archetype is not a question with no takeaways. It's important stuff to consider! The implication could be that a life form found on Earth is in some way multi-planetary, for example, and part of a wider consciousness-granting bio-system.

I didn't downvote you, but you had me at "shared consciousness". Since no neuroscientist or philosopher can definitly tell what consciousness is or how it constitutes, speculations about a "shared consciousness" is idle at best, more probably than not its just plain wrong. Since I don't want to spend time with idle speculation about concepts that are not explained by physical reality[0], I categorized this posting as: "esoteric" and went on. I can only tell you about my reasons not to take this posting serious, but I think others might have similiar reasons.

[0]: A "shared consciousness" must communicate in some way; no signals (in the form of either electromagnetic, gravitic, strong or weak nuclear force) have been detected that could accomplish this.

Thanks for your comment. I think I understand, but I guess I look at shared consciousness as a continuum from "obviously exists" to "highly speculative". In its more obvious form, you and I probably have some sensing hardware in common (not 100% sure since I don't know you, but maybe we both have eyes, for example) so we may share light-consciousness, sun-consciousness, etc. Through one very simple lens humanity can be seen as a mesh sensor network that shares the "consciousness" product. In this way I would expect that any form of life with e.g. a nervous system and means of communication (or even just reaction which leads to chain reaction) can at least in basic ways share its consciousness.

On the speculative end perhaps you'd have phenomena like shared intuitions or visions; however that's still a gradient; in some fields like Jungian psychology these are seen as products of a long and convoluted physical sensing processes, not as magic, for example.

Had we established the first Moon base in 1988 as NASA had on its roadmap in 1970 we would know all about this ice and other aspects of the Moon as well :-).

I also agree with Tomas who opined that for a long time it was presented that water was 'rare' and somehow special. And while we can agree that the triple point is pretty narrow set of conditions that have to exist, we now know it flowed on Mars at one time, is probably currently flowing on Europa, and that ice is literally everywhere.

Time to rewrite our Science Fiction tropes.

This discovery of so much more water ice on the moon than previously thought is such a boon for ISRU and future moon habitats and industry if we ever get around to continuing the space race.

We could crack lots of cryo propellant, and far more easily than the old plans. The moon could become a huge propellant, fuel, structural materials and life-support depot with a very easy gravity well to get out of--way easier than Earth. That makes it very important for future Mars missions as well. It's easier to stop off at the moon for a bit than to go straight to Mars from Earth.

Regolith has all kinds of neat stuff in it, such as aluminum and that legendary helium-3 which may or may not be a miracle fuel if fusion ever breaks even (and we figure out how to do it with aneutronic fuels, which is way harder). The aluminum can be made into solid rockets, which are good enough to get off the moon but damn near useless for anything else because of their pathetic specific impulse. But it would be a great way to get this water off the moon without having to waste much on shipping.

If we set up nuclear furnaces we could crack some of the minerals to get oxygen, but it would be so energy-intensive compared to melting ice, and hydrogen is super rare on worlds with easy gravity wells. Hydrogen likes to sublimate off into space and there's practically none anywhere this late in the game. That would be a big bottleneck on ISRU. But all this water ice hidden away near the surface really changes things.

Now if we'd only get serious and go nuclear and get people back in space. Check out the always incredible Atomic Rockets by Winchell Chung for great spacecraft diagrams, mission profiles, pdfs of charts and graphs and nomograms and more. It's a treasure trove for space nerds who wish NASA went the way we thought it was going to go in the fifties and sixties. http://projectrho.com/public_html/rocket/

> Had we established the first Moon base in 1988 as NASA had on its roadmap in 1970 we would know all about this

You say that offhandedly, as if they decided not to move forward with a Moon base due to bureaucracy or because some upper management people decided to go in a different direction.

A permanent moon base in the 70s and 80s was largely impossible as far as the technology is concerned. Hell, we're approaching 2020 and we still have several major hurdles before we could put a permanent base on a body or planet that is not earth. Everything from radiation to supplies are still problems that need solved. Expecting them to solve them in the late 70s or early 80s is almost laughable.

I know HN and reddit likes to think it was congress who is responsible for the shift in NASAs goals (after all, they control the purse strings so they get to dictate/approve budgets & goals), but they did so precisely because NASA told them it was impossible to establish a permanent moon base at that point in time. On top of the insane cost, what more was there to be gained that justified the immense cost? If they wanted to go to the moon and study rocks, that's what the Apollo program was for. There was only so much we could learn with the technology we had at the time. People forget, the rest of the solar system awaited exploration too, but only so much money to go around.

"But we can use the moon as a base to launch further missions out into the solar system and beyond!" It's a nice pipe dream, but getting the materials there and/or manufacturing facilities to create everything needed is cost prohibitive. Also, the logistics of doing something like that today is insane, let alone 30 years ago.

If the US had established a colony on the moon, would that colony have eventually declared independence?

I hear you, and my comment was more wistful than accusatory, because to my grade school self, after NASA had landed on the Moon I believed them when they said they would establish a base there 20 years later. It aligned nicely with my plan to be an astronaut in good standing by then so I could be the base's first commander (such are the dreams of a young man enthralled with science).

When I was in college, I got a chance to intern with Jerry Pournelle who was on the White House science advisory council and we talked about moon bases at one point. Jerry asserted (and I believe him) that NASA had a program "ready to go" to put a permanent installation on the moon. The budget challenges however were large.

I also got to meet Gerard O'Neill through Jerry who was pushing for colonizing space and had lead NASA to develop plans for how a Moon base would support the development of space habitats.

This let me understand that while the technical challenges were hard, they were engineering and budget challenges, no new science or equipment or materials had to be developed. The same materials that survived for years in orbit would survive on the Moon, the same resupply requirements that there were for a space station there would be for the Moon etc.

President Regan was open to the idea but the only way to fund big space initiatives was to make it sound like a war. That has historically been the only motivation that gets Congress to appropriate the funds. And in the late 70s, early 80's it was going to take a lot of funds.

Really smart people tried to make the argument that the economic benefits of adding 'space' to a country's economic operating zone would be immense, and create growth that could be taxed to fund the rest of the expansion fell on skeptical ears. Even O'Neil's pitch that space based solar power satellites would give the US a built in economic advantage; 'Cheap' energy would lower the development cost of all goods. Wasn't enough to get people to commit to the groundwork for this. When I last talked with Jerry about this, he suggested that a cost effective single stage to orbit capability, built to support Regan's SDI initiative, would enable space colonization as well (that was in 1990 or 1991).

Here we are, nearly 30 years after 1990, and SpaceX is on the cusp of making access to space an order of magnitude cheaper than it was in the 90's. This presentation [1] from 2007 could have been the SpaceX pitch deck!

Now I need to go dig around and see if I can find NASA's plans they did in the 80's.

[1] http://www.dglr.de/fileadmin/inhalte/dglr/fb/r1/r1_2/06-Raum...

I would have believed that there's some tech that allows an orbiter to detect water under the surface. It seems that such a thing doesn't exist. What's next, droping bombs to study debris and ground waves?

The technology does exist it's called radar, and there is already a mission on the books (the Jupiter Icy Moons Explorer, or JUICE) which will take just such an instrument to Jupiter and its moons in the early 2020s.

P.S. There's also Europa Clipper, but the funding is less certain: https://en.wikipedia.org/wiki/Europa_Clipper

Radar has also been used to map underground ice deposits on Mars, see eg. [1][2].

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

[2] https://en.wikipedia.org/wiki/MARSIS

I don't remember if the moon was the target, but I recall there was a probe in the last 30 years or so that was deliberately crashed into something just to study the debris that was kicked up.

You might be referring to Deep Impact [0], which wasn't even quite that long ago.

[0]: https://en.wikipedia.org/wiki/Deep_Impact_(spacecraft)

Going back further, the original impactor was Ranger, I think. Video just prior to impact:


I don’t know about bombs per se but plenty of stuff has been deliberately crashed into the moon to study its seismic structure etc.

I wonder if these water deposits are near craters that are in permanent shadow and always below freezing. You could send a relatively small robotic setup that would melt the deep ice into water and use it to form structures on the crater. Now you have a permanent moonbase without bringing in tons of material via rockets.

The craters full of permanent shadow are at lunar poles and we had already discovered water in one of them[1]. This discovery is that there is probably a lot more water in other places on the moon, but probably far under ground if it hasn't boiled off during the harsh lunar day.


It would be a far better use of the water to save it for life support or crack it into hydrogen and oxygen. Regolith can be used to create structures without having to haul everything up out of Earth's gravity well. It's also chock full of aluminum, so that would be easy to make with a nuclear or solar smelter. But water would never be used as a structural material, that would be a tremendous waste.

...until you try to heat it to a reasonable temperature, the walls melt, and all your atmosphere off gases in to space.

Water is a pretty useful resource. It is also more weight to bring into space. Having it already available at a location would be tremendously helpful. Using that water to build space igloos would appear to be a poor use of a valuable resource.

You'd have to lay insulation against the ice so you can have a warmer interior, but that's still a pretty good mass savings. You'd use ice for the heavy structural elements and then only lift the lighter stuff.

The more pressure you put on ice, the more it wants to turn into liquid. So your "heavy structural elements" can't be bearing too much weight.

On the moon, it could bear six times the mass it would bear on Earth.

If you put a fish in some heated moon water on the moon, could it swim in it and live?

Maybe for a brief time, until the water turned to vapor or if it were in a hermetically sealed container, until the water ran out of dissolved oxygen for the fish to breathe.

So for aquatic life, some of these worlds could potentially already be terraformed?

I think the fish also need food. Alge, seagrass, bugs, crustaceans etc.

Not really. For the brief time the fish will survive in an un-enclosed container of water on the Moon's surface, they'll be fine without any food. By the time they get hungry, the water will all be vaporized and they'll be dead.

Oh I was referring the comment about "terraforming" other planets/moons that have water by plopping fish into the oceans there.

we potentially already could have but didn't because why would we, what's the use? There's already plenty of fish in the sea, so to speak.

To seed life on other worlds?

if there are rocks and gravity, there is water. the gravity crushes the rocks and forces the hydrogen and oxygen out, and it forms water. So basically there is water everywhere in the universe. The "we found water" meme is just tabloid headlines recycled over and over again, much like "voyager leaves the solar system" every year -- wine is good for you, wine is bad for you, antibiotics are causing resistence, etc, etc. Go look at any Popular Science magazine from the 90s and now, the same damn narratives repeated, rephrased, and re-rinsed.

Given relative elemental frequency in the universe, and propensities to form molecules, water is likely the third most common molecule whhich exists, after molecular hydrogen and oxygen.

The second-most prevalent element, helium, doesn't form molecules (to any meaningful extent, if at all).

Methane (CH4) likely comes next.


I'd like to see the math on this electrolysis-via-gravity theory of yours. Usually it takes the likes of a nuclear furnace to squeeze oxygen and hydrogen out of a rock.

On airless worlds with less gravity than ours, water near the surface tends to sublimate and float off into the great old void. It's extremely rare to find it in places that are relatively easy to access. Even Earth isn't a great source, because all that atmospheric drag and gravity makes water a pain to loft up and out.

This new store of ice on the moon is right on our doorstep. Europa is not on our doorstep. Having it on the moon changes all the plans for future manned missions outside Earth's orbit. With hydrogen and oxygen readily available on the moon--and without nuclear reactors and massive chemical processing plants--it suddenly becomes a complete no-brainer to go over there and start making stores of cryogenic fuel for our more ambitious plans.

That is if we ever undertake another ambitious plan. New Horizons was amazing, it really was. But it's nothing like a manned flight.

People say robotic exploration is just as good, but the intangible things really matter. They really do. Think of just how much the moonshot in the 60s drove people into STEM and got everyone excited about the future. Look at science fiction then vs. now. It went from utopian and focused outward to heavily dystopian, obsessively focused inward. It's so sad.

It's impossible to calculate the value of the inspiration of the moonshot, let alone the advances in technology (solid-state computers anyone?). Just imagine how much of a boost it would give our society to go to Mars. This discovery makes it a lot more closer.

Guidelines | FAQ | Support | API | Security | Lists | Bookmarklet | Legal | Apply to YC | Contact