Rosetta fuels debate on origin of Earth’s oceans

Rosetta has found that the composition of the water vapour at Comet 67P/C-G is significantly different to that found on Earth.

The observations were made by the ROSINA instrument and are reported this week in the journal Science. Our full story is published on the ESA web portal – read it here.

ESA_Rosetta_Rosina_DHinfographic

The measurements were made in the month following the spacecraft’s arrival at Comet 67P/Churyumov–Gerasimenko’s on 6 August. It is one of the most anticipated early results of the mission, because the origin of Earth’s water is still an open question. A leading hypothesis is that comets and asteroids played a role in delivering it to Earth, but the relative contribution of each class of object to our planet’s water supply is widely debated.

The key to determining where the water originated is in its ‘flavour’, in this case the proportion of deuterium – a form of hydrogen with an additional neutron – to normal hydrogen.

Previous measurements of the deuterium/hydrogen (D/H) ratio in other comets have shown a wide range of values. Of the 11 comets for which measurements have been made, it is only the Jupiter-family Comet 103P/Hartley 2 that was found to match the composition of Earth’s water, in observations made by ESA’s Herschel mission in 2011.

By contrast, meteorites originally hailing from asteroids in the Asteroid Belt also match the composition of Earth’s water. Thus, despite the fact that asteroids have a much lower overall water content, impacts by a large number of them could still have resulted in Earth’s oceans.

It is against this backdrop that Rosetta’s investigations are important. Interestingly, the D/H ratio measured by the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis, or ROSINA, is more than three times greater than for Earth’s oceans and for its Jupiter-family companion, Comet Hartley 2. Indeed, it is even higher than measured for any Oort cloud comet as well.

“This surprising finding could indicate a diverse origin for the Jupiter-family comets – perhaps they formed over a wider range of distances in the young Solar System than we previously thought,” says Kathrin Altwegg, principal investigator for ROSINA and lead author of the paper reporting the results.

“Our finding also rules out the idea that Jupiter-family comets contain solely Earth ocean-like water, and adds weight to models that place more emphasis on asteroids as the main delivery mechanism for Earth’s oceans.”

This is just an excerpt from our story published on the ESA web portal today; read our full report – including more background information and graphics – here: Rosetta fuels debate on origin of Earth’s oceans

Comments

56 Comments

  • THOMAS says:

    Just heard this breaking news on French national radio and rushed to my computer….

    So the first officially acknowledged scientific paper on the Rosetta mission (but perhaps the second, from what I understand Professor Harvey Rutt to have recently posted on a parallel thread), published in “Science”, has, according to the observations made by Rosetta’s ROSINA instrument, just conceded that comets are actually not the H2O-based objects hypothesized over 60 years ago by Fred Whipple which were more recently theorized to have been the main (and perhaps unique) source of the Earth’s oceans.

    Instead, it is already hypothesized by the quick-start authors of the article in question, that there should be”more emphasis on asteroids as the main delivery mechanism for Earth’s oceans”.

    To put things into perspective, perhaps it is time to remind people that asteroids have always been considered to be lumps of *ROCK* with a mean estimated density of around 2.7g/cm3, containing minimal quantities of water (if any at all…).

    But suddenly, asteroids are now thought to contain considerably more water than comets!!!

    It is truly (from a standard "dirty snowball" perspective) an astoundingly topsy-turvy Universe, the exact opposite from EVERY point of view of what was expected at the time of Rosetta's launch over ten years ago, just as in Lewis Carroll’s "Alice Through the Looking Glass". (See the comment I posted on the inside-out logic of 67P here: http://blogs.esa.int/rosetta/2014/11/18/philae-settles-in-dust-covered-ice/#comment-213110.

    The ever-continuing and ever-lengthening flow of disappointed mainstream expectations in the face of actual observations never fails to amuse me, just as the totally inverted logic of the “Alice” books always has. (“Lewis Carroll” was in reality just the pseudonym of the renowned late 19th Century Oxford professor in mathematics Charles Dodgson, who wrote the “Alice” books ostensibly to amuse the two young daughters of the Christ Church Dean, but above all to denounce what he already perceived as the growing and pernicious stranglehold of “pure” maths on the natural sciences.

    I sense that there's much more fun to come as competing teams will start vying to publish their “game-changing” articles in the most prestigious journals on the clearly discordant data (in terms of the requirements of the standard snowball theory) which is currently pouring in from Rosetta. The flood-gates are apparently just starting to open….

    I sense there's much more fun to come.

    • Dave says:

      Thomas

      As you say, more fun to come.

      Still not much data where the ice is either.

      but Asteroids?

    • AndreH says:

      Typical EU / conspiracists believer line of argumentation.....first you.
      First you use the result of a theory you DO NOT HOLD TRUE to proof that same theory wrong. (Rosetta could only arrive the comet, because the theory about gravity used to calculate the trajectoy IS CORRECT).
      Then, after claiming there CANNOT BE ANY water because rosetta OBCIOUSLY looks like a rock, you use the findings made IN THE WATER PRESENT THERE to again postulate that mainstream most be wrong.
      Typically "wiping away of what I said yesterday" all CT'ers use. They bring up a point to reason their theory is correct. Than this is prooven to be wrong. Than they ignore that and jump to next the point. After having this done 99 times, they still say: Ha here is point 100, you cannot proof me wrong yet, so I am right. Despite the fact that 99% of what they are saying is wrong. So the water on rosetta is not the same like the oceans on Earth? So what? This only tells us "rosetta type comets did most likely not bring the water to Earth" not more, not less.
      If 1+1 = 2 and 2 + 2 = 4 than 1+1+1+1 = 4.

    • Daavs says:

      The finding has nothing to do with what percentage of the comet's total composition is water, only with the ratio of the water molecules observed to have extra neutrons in the hydrogen molecules.

      Your smug electric comet conspiracy theory posts are always fun to read though.

      • THOMAS says:

        @ Daavs

        "Your smug electric comet conspiracy theory posts are always fun to read though."

        Thanks for the backhanded compliment.

        I guess smugness is in the eye of the beholder. The tone and the content of my posts are simply born of citizen science conviction. (I gave the standard theory up for lost around 15 years ago when its headlong “Alice Through the Looking Glass” logic finally got too much for me to stomach). I hope you at least find them cogent, since I always make a point of actually arguing the case I'm trying to make, on the basis of actual observations. I have rarely had anyone on this forum find fault either with my logic or with the observations I reference (though I’ve had people complaining about lack of numbers and equations…). I honestly believe that pertinent observations and impeccable logic are a minimum requirement on a science forum such as this one, as being the very foundation of true scientific method. And I hope you continue to find my posts fun to read…

        Concerning your "electric comet conspiracy theory" claim, I for one have never believed for one instant that there was any sort of secret “conspiracy” on the part of mainstream astrophysicists to suppress evidence of alternative models. It just so happens though that, whatever the branch of science concerned, the Establishment naturally and openly uses every means in its power to maintain the integrity of what it considers to be “known science”, as if it considered this to be a public duty, even in the face of totally falsifying data. It was already the case, most famously, in the early 17th Century when the scientific and ecclesiastical authorities of the age refused to take account of Galileo’s telescope observation of Jupiter’s moons. It is still true today. That’s what Establishments are for, to maintain the status quo and thereby the corporative and individual power, profit and security its members derive from it.

        The corollary of your “electric comet conspiracy theory" claim is quite simply that the present-day astrophysical Establishment is objectively being increasingly challenged by the observations flooding in (and not just from 67P) and is perhaps becoming increasingly paranoid in reaction to the serious threat which this is increasingly posing for its credibility and its very integrity.

        Finally, and to address your initial point, whatever the truth about the percentage of water in the comet’s composition, which is still far from being known (supposing that there is any at all…), Kathrin Altwegg’s hasty publication of such unequivocal and damning conclusions for one of the mainstays of standard cometary “dirty snowball” theory as it has evolved over the years (the idea that comets may have been at the origin of Earth’s oceans), coupled with her suggestion that is more likely to be “asteroids”, finally, which supplied the ocean-water (!), seem to be a sure sign of an increasingly challenged model.

  • Jacob nielsen says:

    here are my little reflections on relative deuterium abundance on 67p: the comet is not a time capsule! The surface and maybe in this respect: subsurface, is active. Water is cycled between a solid and a gaseous state. During this cycling it does matter what isotope. Deuterium does slow things down by a (small) fraction. Over time, relatively, more H2O will be lost by escaping nucleus' gravity. This will raise the relative abundance of the heavy isotope. The question is: by what magnitude? Other non random distribution (fractioning) could take place on the basis of the marginal differences in chemical/ physical properties... No, I haven't read the article yet, don't know if this is accounted for in any way.
    By the way: biological systems are highly destinctive here: maybe there is some yet unknown chemistry on the surface of 67p, that treat isotopes differently?
    This was just to suggest mechanisms other than primordial distribution as the key to present day distribution.

    • Jacob nielsen says:

      I think more likely fractioning mechanisms would be more likely during formation stages (agglomeration). I guess the current consensus is that different "macro regions" have different distributions, and that detection is random sampling: outer solar system different from inner solar system etc. What I suggest is therefore non-random sampling is taking place: the detected isotopes in the coma may not be a random sample of the distribution present where 67p was accreted (or otherwise formed). A fractioning effect would be evidenced by a higher than expected ratio of D2O:HDO based on the HDO:H2O ratio. This would require a larger sample than that required for the HDO:H2O determination, but would be possible?

      • Jacob nielsen says:

        That last bit was nonsense, because of the dynamic eqilibrium H2O OH- +H+, silly me.

    • Jacob Nielsen says:

      so let's chase asteroids instead?:

      "“Today asteroids have very limited water, that’s clear. But that was probably not always the case, said Altwegg. In the earliest period of the solar system, 3.8bn years ago, asteroids are thought to have crashed into Earth regularly in what is called the late heavy bombardment. “At that time, asteroids could well have had much more water than they have today,” Altwegg said."

      (source: http://www.theguardian.com/science/2014/dec/10/water-comet-67p-earth-rosetta)

      • THOMAS says:

        @ Jacob Nielsen

        Wikipedia: "The Late Heavy Bombardment (abbreviated LHB and also known as the lunar cataclysm) is a hypothetical event thought to have occurred approximately 4.1 to 3.8 billion years (Ga) ago" (http://en.wikipedia.org/wiki/Late_Heavy_Bombardment)

        i.e. It is only *hypothesized* to have occurred, on the basis of initial hypothetical findings. On the basis of the assumption that the LHB actually occurred, we now have a further assumption that (necessarily) billions of asteroids must have crashed into the Earth at that time, asteroids which (third required level of assumption) "could well have had much more water than they have today" according to Kathrin Altwegg.

        Yet another house of cards being built, as usual, to keep a semblance of standard theory alive. Business as usual in the curious world of Establishment astrophysics.

    • lucas says:

      There is no "water" (H20)found there...

      • Jacob nielsen says:

        @Lucas, If that is your belief, so be it, if you read it here, then where???

    • logan says:

      Hi Jacob. This model is very interesting. As Alembe and several others have said: If comets are extremely 'respiring' during growing - accretion, then this is very well possible. Please don't be too much auto-critical and let it 'grow'.

      • Jacob Nielsen says:

        I AM trying to turn auto-criticism low - as you and others may have noticed.

  • Robin Sherman says:

    Thanks to Kathrin, Emily and the ROSINA team for this information. So one of the BIG questions Rosetta was hoping to answer, is still unanswered, though at the moment it would seem slightly less likely that most of Earth's Water came from comets. This data is from the early coma and we have seen the majority of the outflow was from the neck region, close to the centre of the comet, so the Deuterium/Hydrogen ratio may be skewed towards the heavier type of Water. Later readings taken when more Water from the outer regions of the comet contribute to the coma, may tell a different story.

    This also raises the other question of whether comet's seeded the Earth with prebiotic organic molecules. The visual evidence is that 67P has lots of complex organic compounds on it's surface, but if the likelihood is that not many comet's actually impacted the Earth during the Heavy Bombardment epochs, that would now seem to be in considerable doubt too.

    I guess the conclusion must be that 67P actually originated a very long way from the Sun, perhaps on the outer edge of the Kuiper Belt, or even on the fringes of another solar system with a different ratio of Deuterium to Hydrogen, maybe with a smaller star or Brown Dwarf. It then got flung out or came too close to our Sun and got pulled into our solar system. The Sun orbits the Milky Way and must have passed close to a multitude of other solar systems in the last 4.5 billion years. The GAIA data will be interesting from that point of view.

    • THOMAS says:

      Robin, you say "This data is from the early coma and we have seen the majority of the outflow was from the neck region, close to the centre of the comet, so the Deuterium/Hydrogen ratio may be skewed towards the heavier type of Water. Later readings taken when more Water from the outer regions of the comet contribute to the coma, may tell a different story."

      I assume you know about how academic science actually works. If those in charge of this major, high-profile Rosetta instrument team have so quickly released such damning findings with respect to one of the blue-chip expectations of standard theory, then that means these people are absolutely sure of their conclusions. Namely, that if Earth's oceans indeed have an extraneous origin, then it can't be from comets like 67P, but maybe from asteroids. The scientists concerned are necessarily and understandably keen enough to preserve their academic reputations not to have rushed into print without being surefire certain of the conclusive nature of their findings.

      I would love to see the same sort of rapid publication from the other instrument teams involved.

      • Jim Thompson says:

        Dear Thomas,

        I have read through your posts on this site, initially with mild amusement but now, after this direct personal attack on Robin, with much anger. Your statement "I assume you know about how academic science actually works." is extremely insulting, to the point where I feel I need to apologise to Robin on your behalf. The fact you would address someone in that tone on an open forum suggests that it is in fact yourself who does not know how real professionals behave and interact. The way you have interacted with others on this forum has not served to help your Electric Universe cause.

        Now, regarding your position that the OP regarding comet 67P not having water with the same chemistry as Earth's water...in your own words: "...so quickly released such damning findings with respect to one of the blue-chip expectations of standard theory...". I'm sorry but this news article is in no way damning of existing theories on the make-up of comets or the origin of water on Earth. The news article clearly states that comet 67P is one of eleven comets for which the hydrogen/deuterium ratio has been measured... ELEVEN! Eleven does not constitute a sample of a population, not by any stretch of the imagination. The findings are nothing more than a curiosity. Anyone who makes a conclusion about the origin of water on Earth or the nature of comets from this new single data point is out to lunch.

        Finally, I know this is coming so I want to nip it in the bud now if possible. If you were thinking of posting about how the ESA team has recorded images of lightning in 67P's coma but the "Establishment" is keeping the evidence from the public, please don't bother.

        Regards,

        • THOMAS says:

          Hi Jim,

          Sorry for not responding earlier, I’ve only just revisited this thread after devoting my main attention in the meantime to more recent ones.

          I honestly don’t understand how my "I assume you know about how academic science actually works" can in any way be construed as a “direct personal attack on Robin”, nor even as an insult. As for your own “anger”, you are, of course, perfectly free to feel whatever you like and for whatever reasons. It has nothing to do with arguments, which are the only things that should matter on a science-board such as this one.

          I have only ever tried to “interact” with others on this forum concerning the FACTS, THEORIES AND ARGUMENTS they have put forward and Robin himself recently referred, on another thread, to my “usual cogent adversarial style” to say he was disappointed with a particular post because it was below my usual standard…

          And whether you like it or not, I maintain my argument that Kathrin Altwegg would not have rushed into print if she had not been 100% sure of her observations and conclusions. These were undeniably to the effect that if the Earth’s oceans have an extraneous origin, then we should look rather to asteroids (which “could well have had much more water than they have today”, as she claimed in the Guardian), than to comets. What can you find fault with in my position?

        • THOMAS says:

          Hi Jim,
          Sorry for not responding earlier, I’ve only just revisited this thread after devoting my main attention in the meantime to more recent ones.
          I honestly don’t understand how my "I assume you know about how academic science actually works" can in any way be construed as a “direct personal attack on Robin”, nor even as an insult. As for your own “anger”, you are, of course, perfectly free to feel whatever you like and for whatever reasons. It has nothing to do with arguments, which are the only things that should matter on a science-board such as this one.
          I have only ever tried to “interact” with others on this forum concerning the FACTS, THEORIES AND ARGUMENTS they have put forward and Robin himself recently referred, on another thread, to my “usual cogent adversarial style” to say he was disappointed with a particular post because it was below my usual standard…
          And whether you like it or not, I maintain my argument that Kathrin Altwegg would not have rushed into print if she had not been 100% sure of her observations and conclusions. These were undeniably to the effect that if the Earth’s oceans have an extraneous origin, then we should look rather to asteroids (which “could well have had much more water than they have today”, as she claimed in the Guardian), than to comets. What can you find fault with in my position?

  • Cometstalker says:

    This debate that something from outside "seeded" oceans or atmosphere on Earth is extreme rubbish formed by people that believe in Santa Claus and had a far too long potty training. What seeded Venus or the rings of Saturn? Why did Mars not get "seeded". The kindergarten model of how our planetary system was created is only a colorful model not very realistic. A lot of models are available and none of them can be proven. The foul thing is that people that are supposed to be scientists are trying to claim that their ideas are indisputable proven and without failure.
    Its another cold fusion story good for nothing but publicity.
    The ratio D/H is interesting in a lot of ways but not to be used as a tool to paint up a picture that describes a model of how our planet got some Oceans. The mass of our oceans in relation to the mass of our planet is a tiny fraction, the surface it covers is a large factor and to know this difference is essential and not to be misused like foul play. Go to Wikipedia and check the relation of matter of our and other planets and also keep in mind that those are all nothing but estimates as only the total mass is known and only the surface is sampled on a few planets. Its time to set an end to ferry-tales like Oort cloud and its likelihood in astrophysics and to put a quality stamp on all collected data that clearly shows the worthiness and accuracy involved. The 67P/G-C is a comet that is special and not common as all comets that so far are sampled are few and the sampled data are far from significant. It is not possible to describe how this comet and other comets did have their origin and how they represent comets in general. To measure whatever is possible is nice and worthwhile but to jump in the air an yell hurray we got the answers is not very smart as we saw what happened at the Philae landing when the guys jumped to the debounce, spoke rubbish and made inverted smilies at the other debounce and landing.

    Analyze this presented graph and realize how little of essence there is in it. Be aware of the logarithmic scale and be sure that only the earth ratio of D/H is accurate. Then take into account the influence of the solar wind and the halve life of D and if you are a bit open minded you soon see the huge amount of uncertainty in the data presented. This is more propaganda then science an a misuse of research recourses.

    • Cometstalker says:

      http://www.nasa.gov/vision/universe/starsgalaxies/fuse_stars.html
      This link describes how Deuterium was created and how it is destroyed and in what life span

      Also a few chemical processes can alter the amount of deuterium sampled.

      • Jacob Nielsen says:

        exactly: (quote:) "In 2003, Bruce Draine of Princeton University, a team member on the new result, developed computer models that showed how deuterium, compared to hydrogen, might preferentially bind to interstellar dust grains, changing from an easily detectable gaseous form to an unobservable solid form. The new FUSE data strongly support this theory."

        Methinks: As there is no good explanation to why D:H ratios should vary, it would be more productive to study the mechanisms of variation, rather than to use the ratio as a "tracer".

      • Cometstalker says:

        http://hearingvoices.com/news/2009/09/water-and-air/

        This link clearly displays the amount of water and atmosphere volume of the planet Earth. It is then easy to realize that those models of "seeding" our planet is rubbish. To claim that our young earht was a molten, hot and dry place is so wrong that ever can be. Observe Venus today with its hot surface and dense atmosphere and realize that the young earth too had a very dens atmosphere and what remains from this young atmosphere is our oceans and our biologicaly altered, oxygen rich atmosphere as seen today. Who claims that the gas planets are seeded? Modern scientists tend to fokus on making headlines instead of proper research. The D/H ratio is nice to have and interesting in a lot of ways but has nothing to do with impacts of asteroids and comets on our planet.

      • lucas says:

        The article is all speculations. The simple and irrefutable fact is that so far no H20 was found on the comet. End of story and speculations. The dirty snowball theory failed.

        • Jacob Nielsen says:

          @Lucas, can I just add that this is your personal opinion?
          - So that anyone stumbling upon your comment is not needlessly distracted from the fact that water has been found in abundance, and now has a determined D/H ratio.

          • THOMAS says:

            @Jacob Nielsen

            "the fact that water has been found in abundance"

            Where has this "fact" ever been stated and by which mission scientist?

            Where has water been found "in abundance" (and, above all, how do you quantify "abundance")? At the surface? In the coma?

            I would likewise wish to prevent anyone who stumbles upon your comment from automatically believing that Kathrin Altwegg's D/H ratio observations have in any way accredited the "hidden-sublimating-ice" theory. They haven't. I would even go as far as to say that her newly-acquired preference for "asteroids" as more probably being "the main delivery mechanism for Earth’s oceans" has had the effect of inspiring ever less confidence in the dirty snowball model of comets.

  • frankebe says:

    Now that's interesting! What kind of water is found in Martian rocks?

  • Bruce says:

    Given that, in addition to Hartley 2, one other Jupiter Family comet 45P/H-M-P (Honda–Mrkos–Pajdušáková) has a D/H ratio close to the terrestrial value, I'd be more inclined to question the origin - or perhaps the history - of 67P/C-G.

    Comets are classified based on their current orbit. It is a big step to assume all short-period comets are formed in the Kuiper Belt; and all long period comets are fomed among the giant planets and later ejected to the Oort Cloud. The Solar System is just more complex than that.

  • Fred Bichl says:

    Interesting that vapors and dusts and gravels are being emitted from the comet.

    Too bad about the lander's harpoon failing. It would be worth repeating for the next appropriate comet. Civilization probably has time if climate change doesn't' get us first.

    • Jacob nielsen says:

      How about catching Hartley 2? If a much lower mass satellite is used, a much faster mission could be accomplished. That would ofcourse require some solutions to transmission back to earth... Here is the solution 😉 :store all data in the satellite and relay them back -en bloc -on close approach to either Earth, or some sampling point (other satellite) this type of mission would then have to be largely autonomous.

  • GEORGE says:

    what a silly debate. use your imaginations not the "data" from machinations.

  • Dave says:

    Is it time to take the short film Ambition off the blog?

  • DavidW says:

    So if other planets was bombarded with comets or asteroids made up of heavy water, and seeded with life. How would life evolve differently? Taking other factors out of the equation, i.e. Gravity, climate Etc.
    Any views?
    David

    • Jacob Nielsen says:

      I suppose we could drink the (filtered!) water from 67p - it is not all D2O: less than 1 i 1000 water molecules are HDO, meaning less than one in a million D2O.
      Notice: this is about the highest ratio D:H observed so only small implications to life. (Drinking 50% or more D2O kills you)

  • Fabio says:

    How comes that "some unknown process" can be invoked when some theoretician needs to save his theory? So what, according to data, the theory is complete with or without additional pieces? Btw, it seems to happen the same with the cosmological constant: how mad is that it was rejected as long as it could stop the expansion theory but now, as it can save that very theory, it is welcomed?

  • W. Blent says:

    I don't understand Thomas' comment. CG does contain water, but not the same kind D/H ratio that is found on Earth, so maybe this kind of comet isn't the source of water on Earth. But since other comets and asteroids do have the same ratio, even comets in the same kind of orbit as CG, the water on Earth could have come from those. This isn't a surprise to many scientists since there has been discussion and publications for years suggesting that for dynamical reasons asteroids might be a significant or primary source of Earth's water, even if the fraction of water in an asteroid is very, very small.

    • THOMAS says:

      @W. Blent

      Kathrin Altwegg has gone on record as saying that on the basis of the ROSINA findings, asteroids now seem to be more likely candidates than comets "as the main delivery mechanism for Earth’s oceans".

      I simply find that a very striking statement, particularly since she is then forced to hypothesize that asteroids "could well have had much more water than they have today" (http://www.theguardian.com/science/2014/dec/10/water-comet-67p-earth-rosetta)

  • logan says:

    So Ducky could be a recently 'fallen angel'. Orbital energy should be orders much greater. A recent impact deep down here could be an scenario. Any big scar looks recent?

  • Dave says:

    Surely the fact that some asteroids have some water on them and may have crashed onto the earth is irrelevant.

    The big issue for 67p is how and where it was made, supposed to be a remnent of the protoplanetory acretion disc, but now looks doubtful

    So we now know comets like this did not seed the earths oceans But;
    Does the fact that its not playing ball cast some doubt on the acretion theory?

    • Cometstalker says:

      Where it is made is not possible to estimate due to the gigantic timespan of its existence but how it is made is essential and very interesting to find out. The high D/H ratio can give some clues as D can get locked up inside dust particles and released later altering the D/H ratio significantly. This process is worthwhile to research and when the NASA mission to an asteroid is successful the collected and returned samples are of uttermost interest. A small chance that Philae is recovered is there as well. So far this might be the big hit on this mission.

  • Dave says:

    Jacob,
    are we not in still in the same Limbo

    Water in the atmosphere, but no mention of water ice on the comet, surface or below surface.

    • Jacob nielsen says:

      Lots of water in the coma. One wild guess: it must somehow originate from the nucleus. Wilder guesses do exist, but they are.. wilder.

      • Dave says:

        Hi Jacob,
        You must agree no h2o on the surface,

        I can agree that the water in the coma and measured near the surface must come from the comet. I cant think of an alternative that is wilder than that.

        I can also agree that I dont know how to account for all of the water by electrical means, although I believe there is at least some water released electrically(NASA papers)
        I can agree that there may be water or ice water inside the Comet, although looking at the exposed scarps it does not look like it.

        So I am happy to wait for the results today so that we will have some facts to base the discussion.
        There appears to be some surprising results so far, so who knows we may both get a surprise.

  • logan says:

    Ducky is the most 'necked' comet we have found.
    There is an exceptional amount of core's core exposed.
    This heavy Deuterium reading could be just a 'neck-ing' issue.

  • CrisisMaven says:

    "... despite the fact that asteroids have a much lower overall water content, impacts by a large number of them could still have resulted in Earth’s oceans. ..." Indeed, maybe. But since these would have carried an "excessive" load of material that would have "bloated" the Earth we then might to re-adjust the original "size" of Earth as a ball of molten dust etc. in its initial phase of creation?!

  • Dave says:

    Crisismaven
    Seems unlikely that we need to remodel earth to make the asteroid theory work.
    Good news that ther is hard data coming this week so that we will all have a better idea what the comet is and what and/or is driving the erosion.

  • logan says:

    But, it is like asking a jet to go into a parking lot.

    Can't see how a well formed comet can come in from the outside an then park just park around Mars-Jupiter, in a 6 years orbit [Neptune has a 165y one].

    Comets like 67P surviving a decelerating impact amounting to this energy doesn't make the cheese.

    Would like to think by now that near comets, like domestic cars, are discretely assembled somewhere around here.

    With heavy water coming from abroad, in the form of much smaller 'crystals', 'hydrate cages', layered by structurally 'stealth' materials, [why not? even 'small modules'], etc.

    67P could be a recently 'assembled' domestic comet.

    Heliospheric mass quite probably is more than what we estimate with current instruments.

  • Jacob Nielsen says:

    Is finding a "messed up" distribution of Deuterium a support for the "Nice model" ?
    http://en.wikipedia.org/wiki/Nice_model

  • logan says:

    Heliospheric current sheet. That could explain the incredibly regular layering. And the very regular magnetic signatures. Good place to be born 67P.

  • logan says:

    besides, tend to think that heliopause is impermeable only to gases

  • Dave says:

    MAYBE THE WATER DID NOT COME FROM COMETS OR ASTEROIDS.

    TRY PROFFESSOR WENDY PANERO - HINTS THAT ANCIENT EARTH MADE ITS OWN WATER.

    Study Hints that Ancient Earth Made Its Own Water—Geologically
    Evidence that rock circulating in the mantle feeds world’s oceans even todayBy: Pam Frost Gorder

    Published on December 17, 2014
    SAN FRANCISCO—A new study is helping to answer a longstanding question that has recently moved to the forefront of earth science: Did our planet make its own water through geologic processes, or did water come to us via icy comets from the far reaches of the solar system?

    The answer is likely “both,” according to researchers at The Ohio State University— and the same amount of water that currently fills the Pacific Ocean could be buried deep inside the planet right now.

    At the American Geophysical Union (AGU) meeting on Wednesday, Dec. 17, they report the discovery of a previously unknown geochemical pathway by which the Earth can sequester water in its interior for billions of years and still release small amounts to the surface via plate tectonics, feeding our oceans from within.

  • AB says:

    Hi, there is something I'd like to understand. I was wondering why the present D/H ratio on the comet should be the same at the moment of it's formation.
    After massive loss of H2O at every perihelion I would expect a fractionation with increasing DHO/H2O values on the nucleus after each time the comet popped by the inner solar system. Is this nonsense? Why?
    Thanks!

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