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As a layperson, I find your lectures to have just the right depth. Your language and explanations of technical terms are accessible, yet I never feel you're talking down to your audience.
We are to clpse to this sin the watwr says this the m45al iro. This wanyns oxulygen and carebon sloqs 5he jpu4rney. 5h4r ptoximity to the sun might be due to carbon
They should call you "Universe Girl" because you just taught me why the gas giants are located in the outer solar system. I've been into astronomy for a long time but never knew that!
Thank you for another great video. So many so called science videos are barely more than a list of facts (often not even that) The "how do we know?" Part is the only part that transfers real knowledge. You have a beautiful balance of educating and entertaining without talking down to the viewers. I have come to expect this from you but never want to just take it for granted.
there are so many robot voiced/obviously flawed a.i. science videos popping up lately it's frustrating. all the more reason to be thankful for rachel doing these for us.
@@meesalikeu I know, I have been sucked in so many times by an interesting title on a thumbnail, only to be let down again. I have moved past frustrated to somewhere closer to infuriated. I heard that YT don't count it as a "view" unless you watch for 30seconds or more. I try to quickly hit stop before the 30 second mark then try to block that channel. (I don't know if that 30 second rule is true) You are right, it does make Rachel's videos even more valuable.
@@spindoctor6385 @meesalikeu a bit late but it may be helpful. The thumbnails on the RUclips main feed/homepage have a 3 dots menu on the right hand side of the title. Through that you can tell RUclips “I am not interested in this video” (you can also specify why) and “don’t recommend this channel”. If you use them consistently you can train the algorithm to show you the type of content and content creators you are interested in and avoid most of the garbage. Remember that RUclips show you more of what you currently click on, regardless of your subscriptions and past habits. I know because I have a wide variety of interests and my focus changes very often. So if you get tired of what you are being fed start using the “not interested” and “stop channel” feature until you get the recommendations you are happy with.
I loved the way you phrased it! "List of facts." So many people go through schooling thinking of science as a "listing of facts." Then, when one of those "facts" turn out to be incorrect, they think "what do those scientists know anyway?!" and dismiss a bunch of OTHER facts. Science really is more a "way of asking questions." I love the way she presents the questions!
I know it's hard to believe and weird, just few minutes ago I was randomly asking myself where Water came from . and then Found your video when I opened RUclips.
Congratulations on the sponsorship! And thanks for another very interesting video! Does the moon have a lot of water locked away in hydrated minerals as well? If not, is it just that the moon has lost all water that was once there to space because of the lack of atmosphere? Also, would it be possible to do an update to this video once the findings from Osiris-rex are announced because I think what we find from that astroid sample may help us better understand this subject. Thanks!
7:48 I _think_ I get what you mean - the initial material was dehydrated minerals and at a later point water was 'brought in' from outer areas of the solar system where hydrated minerals were more stable and it was transferred from the hydrated non-Earth minerals to the dehydrated material that eventually formed Earth. Something like that?
Great video, as always. You’re really dialing in your method of delivery with these videos. And as an audience member, who has some knowledge of a bunch of different sciences, I really enjoy the level at which you teach and explain. Looking forward to more of your videos up and coming, especially the one on early tectonics. I didn’t realize that you were a geochemist before this. And I can see why you talk so much about isotopes. It’s very interesting stuff
Thanks or the video. I read somewhere a few years ago that Saturn's rings have been found to contain water with a very similar isotope ratio to that of Earth's. That is mind-blowing if true - as it suggests a common external source during the formation of the solar system. I need to find the reference for it.
I don't think you're going to get any complaints from the astronomers on here. 🙂 You did a nice job covering the parts of the nebular hypothesis which apply to this situation. I always have to warn my students that, "We're reasonably confident about this based on current observations, but we could encounter new data which calls for a revision." Yes, the question about the origin of Earth's water has evolved since I was in college! If it makes anyone feel better, one of my college professors told us that when he did his doctoral presentation, virtually everything he said to his thesis committee about Saturn is currently known to be incorrect! At the time that he told us that, he was very excited, along with the rest of his team, to see Cassini successfully launched... and we all know that the Cassini mission caused everyone to revise what they knew about Saturn all over again! 😂 Edited: slight edit of spelling
Thank you! And also that's so true, we always have to be ready for revision based on new information, but that's what makes science so exciting! At least to me :D
@@GEOGIRLYes... but telling students to drop $150 - $250 on a brand new textbook for an introductory level course which will become obsolete in 6 months to a year doesn't feel good. 😬 Fortunately, there are decent OERs which do get updated more frequently than most textbooks because they're digital, but I constantly have to revise what I say on each topic. This is good, it means people are exploring the universe. 🙂
I have heared that many exo-planets that have been detected are gas planets close to their star. This goes against the previous held theory that gas planets form in an area further away from its star.
Its much easier to detect large planets close in than far out so theres an element of self selection. Then theres the fact that planets move. It's thought at some point early on Saturn and Jupiter migrated inwards and then out again. We may just be seeing solar systems where the Saturn and Jupiter equivalents are in the stage of being close to their star
I think you are talking about the so-called hot jupiter class of exo-planet. Their discovery has been merely due to the early and limited detection methods available. Humanity's journey for studying exo-planet is still young. As newer tools, such as JWST, are being rollout, other types of exo-planet will come up more.
Also a theory that all planets are gas giants... until solar wind blows them off. Thus snapshot of Sol-system (us) when very much younger would reveal 🌎 as a 🪐
Thank you so much! I have actually been playing around with my camera and microphone set up a lot recently, so I am happy to hear that it seems to be working :D
Your sputtering definition was correct (I did a lot of Mars science in my undergrad). Essentially solar winds can ionize particles in the upper atmosphere where they can be carried away by solar winds and/or go on to knock a bunch of other molecules around which will get carried away. This results in atmospheric loss which in turn leads to water loss.
12:47 Why would Earth's primordial atmosphere be H rich if the accretion disk was volatile poor close in to the new sun? Your doubt over that scenario is warranted.
Earth's water is too heavy, but heavy hydrogen would be in higher concentration in the inner solar system because the lighter molecules would float to the outer solar system in higher concentration. Could that account for the difference of isotopic signatures?
What a great question! I am not sure, but I would assume that the water absence in the inner solar system during planet formation was such that all H isotopes (light and heavy) were transported to the outer solar system. Also, I believe the transport of water to the outer solar system was more about volatility than mass. And if I think about the impacts that either came from asteroids or comets from the asteroid belt or those that were 'soaked' in solar wind, I would assume that those contained a non-preferential mixture of light and heavy hydrogen since I don't think the mass difference between hyodrgen and deuterium would've affected their formation processes, but I am not sure about that. Because on the other hand mass is a major part of planet accretion due to the gravitational pull/mass relationship, so I imagine mass-dependent fractionation of isotopes might have been involved... I am just not sure if the physics of space work the same as those on Earth in that way... Any astrophysics reading this, please comment in this thread! Tell us your thoughts on this, I am super curious now, thank you! ;D
There is also the question of where the planets formed in the early solar system there are some signs that the planetary disk was a lot more wild and wooly than it is now.
Thanks, interesting topic. In order to throw even more complexity into this, there’s the idea of planetary migration although I’m not sure if it’s effected the rocky ones. Also that the distribution of planet sizes in our solar system is not typical based on increasing exoplanets being studied. Creation stories often have the water first and dry land created later. Maybe we’re getting closer with our understanding.
Do we know about the hydrated silicate volumes in the crust/"mantle" of mars ? It may have lost its surface water, but still have entire oceans worth of h2O locked in its subsurface minerals. Also, on early earth, we had little to no atmosphere to shield us from the solar wind (atomic hydrogen) so while earth cant hold on to light hydogen, it was still very abundant in our early "atmoshere" because it was delivered constantly from the sun. That may offered some assistance to the idea of magma ocean generated h2O.
14:56 "Hydrodynamic escape" - yeah.... that phrase hides not a lot of meaning. All it means is that water escaped, but _why_ would water escape Venus? I always find Venus to be problematic in discussing the solar system.
Lol you caught the one thing in the video that I brushed over because I couldn't find an explanation of why venus lost its water that I understood well enough to relay to a camera haha 😂 If there are any astrophysicists that study venus who read this comment, please tell us why! Thanks! ;D
Thank you for a fascinating look at where water might have come from -- while astrophysics is not your direct specialty, your expertise in isotope concentrations and geo knowledge yields observations not easily found anywhere else!
Good video, not too long but long enough to have real content. And while water always gets all the attention, I find the question _How did Earth end up with so much _*_nitrogen_*_ ?_ almost never is discussed. And in the question of life on planets, nitrogen is just as important as water. All living things are made from nitrogen compounds. Nitrogen as N2 or as ammonia would have, like water, been pushed outwards by the young Sun. Mars seem to be nitrogen poor, compared to Earth. Venus' atmosphere also has nitrogen, and I think a good discussion can be had that both Venus and Earth were radically changed early on by impacts. Venus ended up rotating on its axis contrary to the other planets and its own orbit, a sign that something big happened.
This is a great point and an awesome idea for a future video! Thank you! I just briefly looked into it to answer this comment somewhat intelligently and from what I read, it seems that nitrogen gas (N2) is heavier than voltailes common in the gas & ice giants of the outer solar system (such as H, He, & H2O vapor). N2 apparently is also more stable in its gaseous state at higher temperatures than those other volatiles; thus, it remained stable in the inner solar system and became a large part of the atmospheres of rocky planets. I will certainly look more into this for a future video though! I think it will be a really good one considering the underrated, yet incredible importance of N for life! :D
i always wanted to know more about this. thanks for explaining so clearly for us. it's fascinating how earth has so much water, well at least so visibly on the surface anyway, versus the other planets and moons in our solar system and you cannot help but wonder why. i can see how we still do not know how that happened for certain, but at least the mechinisms seem pretty clear. it was probably a mix of all of them.
To me, GeoGirl has offered Probably one of the Best, if NOT the Best, Explanations of where Water on Earth came from BUT the FACT still Remains, "Scientists don't know where the Water came from." It is still just Theory.
Yep, everything I discuss regarding Earth's history is of course hypothesized or theorized not 'known'. That's always important to remember when studying our planet's and solar system's history :)
Any sudden injection of massive amounts of water, in any form from space or the sun, would cause a new oscillation until a new harmony of water and earth deep crust has been reestablished. This could be the cause of the recent glacial oscillation on Earth.
I am from Africa: Ethiopia 🇪🇹 where the longest river in the world which know as Blue Nile (Abbayaa) is started. Say some thing about this river For your yutube family thanks ❤🎉
I know right! I never thought about it before either! When I was reading about it for this video I has that same realization like "oh that makes so much sense" lol! ;D
Another great video. Perhaps you remember the parable of the Blind Men and the Elephant as retold in the poem by John Godfrey Saxe -- And so these men of Indostan / Disputed loud and long, / Each in his own opinion / Exceeding stiff and strong, / Though each was partly in the right, / And all were in the wrong! // I often wonder if all the theories taken together are more right than any single theory on its own. Love your work.
Thank you! And thank you for commenting that! I had a lot of people ask me this question in comments, and it took a while for me to learn enough to make this video, but I am so glad I did because now I have such a better understanding of it as well :D
Just a comment about the Hydrogen content of a primordial earth during its formation ... Atomic or molecular hydrogen will escape from the atmosphere into space when the molecules accelerate to escape velocity from heat. The molecule is light enough that escape velocity can occur - unlike heavier molecules like N2, O2, or CO2. A heavy molecule like CO2 also has additional degrees of freedom for motion so that it can absorb more thermal energy without necessarily accelerating the translational motion. However, this is all temperature dependent, which is then dependent on solar radiation, the temperature of the earth surface, and convection mixing. All of this changes in cold places like the poles, or the night-side of the planet. I think this is also why H2 could actually exist on a planet like Mercury, since the night-side of the planet is not heated by the sun, and it stays that way permanently. Even so, it seems unlikely that enough H2 could exist in the primordial atmosphere to mix with SiO2 minerals to create the water we see on earth today. But, enough of it might have mixed in to lighten the D/H isotope ratio.
Also important to remember that accretion of planetesimals is a response from a collapsing cloud of gas to lose the angular momentum which inhibits further collapse under gravity by the formation of angular momentum sinks be it planetesimal clumping/conglomeration, heat generation via collisions/friction or plasma outflows from the central ionized accretion disk around the forming protostar. So the atmospheric environment the Earth and the other rocky planets would have at this point formed in would be pretty heavily saturated as the flow of hydrogen gas continues to rush inwards to form the Sun. So this bulk flow would be fairly "high density"(astronomically speaking) hot hydrogen and helium gas with traces of other elements which today composes the bulk constituent mass of the Sun.
Planet formation is still a bit contentious of subject as there is several camps of planet formation that have arisen which relate to the direct mechanisms responsible for planet formation as well as the timing of these events. That said to address your confusion on where this hydrogen atmosphere was coming from a key point to keep in mind is that accretion is powered by gravity and the conservation of angular momentum. In this sense matter in an accretion disk is falling towards the center of mass of the system but in order to do so angular momentum must be shed either through the clumping of matter to form clusters which high angular momentum or through the release of momentum as kinetic energy and heat and in the inner most ionized region magnetohydrodynamic plasma outflows In this sense the bulk of material that is forming planets is forming a dense inflow inhibited by angular momentum so any means which can enable this net angular momentum transfer to related sinks is going to be favored energetically whether it be collisions chemical reactions or planetary accretionary inflows forming around large planetesimals that have already formed. Today this hydrogen dominated mass inflow now makes up the bulk composition of the Sun while the solar system's total angular momentum is found not within the Sun but the various planetesimals with the more massive the orbiting compact bodies carrying a greater fraction of this total angular momentum, i.e. most of the solar systems angular momentum is contained in Jupiter. This transfer of angular momentum as necessary in order for the Sun to form and thus planets and the Sun formed relatively simultaneously. Does this help resolve your question? Mars water scenario was likely driven both in part due to atmospheric loss/outgassing but also due to a considerable fraction of Mars's water having formed into mineral hydrates. In terms of rock hydration some pretty insightful details can be found in this paper on hydrous mantle plume upwelling(www.nature.com/articles/s41598-019-43103-y) which suggest a potentially deeper role in thermodynamic cycling on Earth where the interior temperature of the planet moderates the rate and timescale of mantle hydration/dehydration. I can't help but wonder if mantle hydration might even provide an explanation for what force is directly powering plate tectonics given recent evidence in the case of seismic tomography about the Mantles far more dynamic inhomogeneous structure. As for that larger debate on timescale there has traditionally been relatively steady state models as those can be readily computed but there is a strong growing body of evidence both from within the solar system and from elsewhere via observations by Large radio Interferometry which suggest planet formation is a much more rapid disequilibrium process dominated by chaotic accretionary flows (turbulence) where eddies within the flow can in essence undergo direct collapse to serve as spontaneous angular momentum sinks. In our solar system the best evidence for direct collapse laying a much greater role (note that there is still strong evidence for accretion in the case of giant planets) comes from isotopic constraints on the timescale for which Earth must have formed to retain Nitrogen gas as Earth's nitrogen isotope ratio appears to be a close match for the nitrogen ratio of undifferentiated chondritic asteroid material rather than the isotopic mix recovered by comet sample collection missions thus far. There is also fairly powerful evidence in the Kuiper belt fossil from the classical KBO observed by New Horizons 486958 Arrokoth as it seems to match the expectations for an object that has been frozen part way through direct collapse at the time when the solar nebula accretion flow ceased. With Long Baseline Radio Interferometry we have observed what appear to be planets that have formed far too soon for accretionary models to explain as well as a diverse array of highly complex unique and dynamic flow patterns within accretion disks around young protostars. Moreover we have even witnessed time variability in many of these systems with some intense bursts of activity that may in fact be this process being caught in action from far away while others appear to be direct evidence of collisions. In fact earlier this year(I think?) there was a fairly fascinating but also somewhat chilling observation that the light outbursts from nearby accreting protostars appears to occur in discreate bursts which based on the energy are equivalent to several Jupiter masses of material infalling all at once. If such work is continued to be reproduced then there is a good possibility we may have flipped things around and its more the case that rather than stars building planets giant planets build stars. A Colloquium speaker some years back when I was in grad school discussed an interesting calculation where when accounting for fluid dynamics in the dense cores of molecular clouds be estimated that the effective Jeans mass for direct collapse might be closer to 10 Jupiter masses which would be orders of magnitude less than back of the envelop/ spherical cow model calculations would suggest. The recent JWST result finding numerous objects around this same giant planet size range might be the strongest evidence that this model is right.
OMG, thanks so much for all this info! This is super helpful, I am so glad you put this here in the comments so hopefully many people can reference it for more in depth physics info on this topic! :D
@@GEOGIRL Glad I can help it is a tricky topic and one which is still unresolved in many areas with lots of nuance that I haven't really seen addressed outside of papers. There are for instance multiple accretionary models some which resolve challenges with the conventional long timescale accretionary models for example but I figured that would be too complicated for this purposes as at this point the question of disk instability direct collapse and accretion is probably a case of both. Then another point of discussion which I left out for the case of water is the lunar formation impact event and how that would effect the Earth. In early models this was cited as a reason why Earth would need a secondary source of water however its worth noting that our models haven't reached a limit in resolution where the behavior stabilizes with higher and higher resolution models showing a consistent trend of reducing the timescale for the impact while increasing the range of possible configurations and the likely overall amount of violence of the event. In essence some of the newer models involve a far more direct collision that more or less volatilizes the proto Earth and Theia however the high surface tension of the molten emulsion of primarily silicate fluids mostly remain gravitationally bound with many of the droplets of molten Earth falling back to the newly formed Earth with momentum conservation dynamics kicking into play in governing the large scale behavior of the post collisional state. This fluid dominated behavior may be relevant to the whole water situation as we know that under high pressures water in a supercritical fluid state(i.e. where it exists as both a liquid and a gas) and silicate magmas form a stable emulsion which might help retain water. Additionally if when the fluids separate out after settling then the temperatures would likely still be more than high enough for a water vapor layer to become supercritical as supercritical water exists naturally in the Abyss in hydrothermal systems where high enough temperatures and pressures exist simultaneously. In that case when said supercritical fluid cooled it would be expected to naturally decompose into a ratio of liquid and gas states meaning you can get a liquid water ocean before any kind of solid crust could have formed. In this sense in the hours after the collision as the globs of rock in orbit coalesce into a still molten Moon Earth would already be submerged under a hot glowing ocean of supercritical water and steam. This wouldn't be too different from what Venus has going on with its own supercritical carbon dioxide ocean just it would be far hotter and denser with a mix of volatile gases not just water. On a related note an understanding of what kinds of exotic chemistry can occur in several thousand kelvin supercritical water silicate magma interface could in some only partly crazy way be an interesting environment for abiogenesis research given the finding that basaltic glass is capable of spontaneously catalyzing the formation of several hundred base pair strands of RNA. With this I can't help but wonder if some more exotic analog process exists at extreme pressures and temperatures? Material science is showing some interesting kinds of exotic chemistry goes on in the high pressure domain so this might not be as crazy as it seems since this could give you a maximal surface area for rock water fluid interface reactions.
Worth remembering just how much water there is in the solar system. Hydrogen and oxygen being the first and third most common elements and when combined become extremely stable. How it gets distributed through out the solar system is still a developing subject , particularly with regard to the migration of the planets to their present orbits.
yes, it's almost beyond belief how much more water there is than what we thought not so long ago. and its very exciting because of course that is such a basic need for life as we know it. not only can we use it exploring our own solar system, but it must make possible life around the universe even more likely than we imagine.
To use, the water looks significant, but if you consider it covers "only" 30% of the surface, to "only" a depth of 4km (vs an Earth radius of about 6000 km), another way of looking it is that it's really scarce? We have this thin film of water, just like other rocky planets may have had thin films of water. And it might not take that much for us to lose it.
I visited Corpus Christi, Texas to view the annular eclipse last week, and I couldn't stop staring out at the ocean and thinking about how all of that water came to us. Perfect timing!
yay! I always hoped you would do a video on this subject, and you did a great one! thank you ....my guess is that Earth's stronger magnetosphere held the water here, where Venus and Mars didn't have that advantage; Mercury does have a decent magnetosphere, but is too close to the Sun ....but even if there was liquid water on Venus and Mars for a while, without good magnetospheres life could not develop due to radiation
Does Venus really lack a magnetosphere? If that's true, it is very surprising to me. If anything I would have expected Venus to have a more potent magnetosphere than Earth does! Hmm, I guess I'll have to research this now.
I had assumed Venus water went to H2SO4 in atmosphere and is too hot to have in fluid form... How do you incorporate fate of water with the formation of the Moon after glancing impact with pre Earth the imparted spin to Earth and fortified the size of the core. That was before the great bombardment might have rewatered Earth... You may have noticed some Earth sized exoplanets are water worlds... in about the same relative position in the goldilocks zones... could Earth have started on the path to being a water world before the Moon forming impact? You might check out Bruce Betts astronomy classes... they are a few years old now... but they did cover Moon-Earth formation fairly well.
@GEOGIRL I think you covered it very well! This is a geology channel so the focus is on Earth of course, but recent cosmological studies are showing that water-y planets are more common than we thought, and the processes of water formation you talk about here apply to far reaches of the universe.
Yea, well it seems we keep finding it in different regions on Mars, but it is mostly, to my understanding, trapped below the surface in ice or very saline brines. I'm not sure whether fresh water has been found on Mars, this is probably a good time for a mars scientist to enter the chat ;)
Very interesting video, as always. As far as I have understood, Mars and Venus have very weak/non existent magnetic fields and Solar wind stripped most of the water form those planets, unlike on Earth.
I am convinced that Earth is a chthonic world - the rocky core of a mini-Neptune that used to be between the present orbits of Mars and Jupiter. It was smacked by Theia, blowing off the majority of its gas envelope, splitting it into three primary objects - Earth, the Moon, _and_ Mars, and leaving debris which is now the asteroid belt. I admittedly have zero evidence to support my hypothesis. It's just a totally awesome origin story.
Great video! I've always wondered what determined the ratio of ocean water to mantle water. If it were even slightly different, the ocean could overtake all the continents or disappear altogether. Fermi Paradox anyone? In other news, I recently learned that Earth's moon likely had an atmosphere with twice the pressure of modern Mars for a brief period of time, and probably some liquid water as well 👀 I wonder if Geo Girl has a video on it.
Why isn't creation considered a hypothesis? Sputtering explanation for lack of water on other planets, is exactly why water wasn't formed through material processes on earth. Basically, In the vacuum of outer space, water would turn into vapor and evaporate quickly. Due to the lack of atmospheric pressure, the low temperature, and the absence of gravity, water would instantly boil and then dissipate as vapor. The extreme conditions of space cause liquids to boil away rapidly without transitioning through a liquid phase. In space, the water vapor that evaporates would disperse into the surrounding vacuum as individual water molecules. These molecules would not coalesce into droplets or reform as liquid water due to the absence of atmospheric pressure or gravitational forces that would normally facilitate the condensation process.
Hi Rachael, again and again you're expand my geo/astro knowledge. I like the fact that you presented more-then-one possibility, because life is like that sometimes also. I had a chuckle when you mentioned "Astro Girl." Starting 1952, there was a cartoon that was produced in Japan, shown on American TV, called "Astro Boy." I can visualize you and he teaming up, zooming around the world, fighting evil and doing good for mankind (is that still a word these days?). Also, I wanted to mention that Matt from the NHSM, sent you a message via your website, but hasn't yet received a reply. It's about giving a Zoom presentation for our monthly Fossil Club meeting. I hope you can do it :) g.f.s.
Thank you for this amazing video! It's the most clear explanation I have found about water origins on the net. I am not scientist, that's probably why there is something I quite not understand yet: I get that volcanos degassed hydrated rocks from accretion that were in the mantle, but about asteroids, if they are balls or big pieces of rock and ice, wouldn't the ice in them vaporize when entering the Earth's atmosphere? I am not sure how could they make it into the mantle keeping their water and then be degassed by volcanic activity. Any thoughts?
At first I was like "well, I'm pretty aware of all this thanks to everything I read", but then I was like "wait, swallow your pride, this is GeoGirl, you're certainly going to learn something". And I did. Many things. 🙂 🙂
Personally I favor all of those processes, (to one degree or another) for how Earth got it's water. The question for me is what percentage each of those processes delivered to us, and when? I also think the we are still adding material (of various kinds) to this planet every single day. Obviously nothing like the amounts at the beginning, but the process IS still ongoing. So study of things like meteorites, and asteroids is (I think) very geologically important! Thanks for the great video.
i am so here for that mars content lol. Really interesting video. I dont know enough about this my self but could early earth had changed that heavy Hydrogen to light at all? if not is small chance encounter with and interstellar object that brought water enough to give earth a good portion of its water?
1:04 A funny and relatable comic: Wife: Honey, come to bed. Husband: I can't yet, it's important. Wife: What is it? Husband: Someone is *WRONG* on the Internet!
Rachel I still don't get after watching this video which one of these hypotheses which one is the most likely? Also will taking a course on brilliant help me better understand the math and physics involved on the obstacle courses on the show American Ninja Warrior if so how
Very interesting! Thanks! I hadn't really thought so much on the how, I was always thinking that Hydrogen and Oxygen make water, but never the mechanisms, and I am glad I have found out now the variety of ways it could have came to be.
I didn't assume that you would get so much into the intricacies of mass fractionation of isotopes to decipher the evolution of our atmosphere 😂. Loved this video. Keep making these geology videos for us 😊 ❤❤
I remember learning that greater air pressure increases the boiling point of a substance. So when solar winds got rid of Mars’s atmosphere, air pressure would’ve dropped significantly, allowing for there to be more water vapor due to a lowered boiling point, which would’ve then been blown off by solar winds. The only caveat to this might be that if greenhouse gases were removed during atmospheric destruction, that would’ve led to colder temperatures, making it less likely for water to vaporize despite the lowered boiling point. So maybe that’s why there’s still ice left over? 😅
Would extra protons (H) and neutrons come from radioactive decay of heavy elements near the earth's core, which keeps the inner earth hot and molten? Would these skew the heavier isotopes of the O and H in water that came from volcanos?
Earth probably gained its water from many different sources, all of it being mixed and geologically processed for billions of years, making it impossible to figure out where it came from by analysing its isotopic composition.
Problem with the deuterium excess in the asteroid belt: I know the hydrogen isotope composition of asteroids and comets have been used to argue about the origin about the Earth oceans, but in contradistinction to the Earth oceans, the asteroids and comets have been exposed in billions of years to the solar wind and, in some comets, interstellar cosmic rays. According to my amateur reasoning they *_should_* have a deuterium excess due to vaporization and ablation. C.f. the deuterium excess in the atmosphere of Venus! As far as I can reason, the only valid way to determine water content of a certain age on a certain solar system body, is water content in zirkon crystals, whose age has been determined within a certain pretty narrow time interval with a certain degree of confidence.
Hydrogen is the most abundant element in the universe for a reason and hence all molecular compounds of hydrogen will also be the most abundant(more or less). The planets distribute their makeup according to centrifugal forces and the position of the earth is about where oxygen would settle out. They would then start to form hydrogen compounds(e.g., water). All the theories are likely correct to different degrees.
I'm not liking any of the possible explanations. It could be something more outrageous. During the later stages of stellar fusion, after the hydrogen fuel is used up - heavier elements fuse until you get to iron, and even much heavier than iron in the case of a star that goes supernova. One of the steps is C + He --> O. And if for some reason there was a large amount of oxygen that didn't fuse to something heavier before a star exploded, then a massive amount of Oxygen would spew into space - and if it found its way to a cloud of hydrogen somewhere else in the galaxy, you would have a massive amount of space water available.
Wait, will outgassing eventually dehydrate the mantle and cover Earth with all those extra oceans worth of water, or will the planet cool and all geological activity cease long before that can happen?
It's my understanding that Earth will cool to a point that tectonics stops before the mantle completely dehydrates (besides the tectonic plates that subduct continuously bring down more water to the mantle). :)
Diderot invented the encyclopedia. I hope you can come up with a modern equivalent, for the geosciences. People do not have a general grasp, of what should be called essential knowledge. Excellence, as always.
The solar wind added one meter of water to earth over 4 billion years, there are at least three ways to calculate this and you could do a video on this. The real source of the water is stellar outbursts. A 12,000 year cycle of black mat layers with nanodiamonds and tektites.
@@GEOGIRL Thanks for taking the time to reply. I had to re-watch the video to make sure I didn't miss something and I still wound up scratching my head. So I guess a more correct title should be "& How Will We know?"
Well the atmosphere was largely composed of N compounds, namely N2 and ammonia, as well, but when I say hydrogen-rich (at least based on my understanding), it means relative to today, not necessarily hydrogen-dominant, if that makes sense :)
Maybe Theia had an excentric orbit, basically being a massive comet. And when it hit Protoearth, the resulting (double) planet inherited all that juicy goodness.
To try everything Brilliant has to offer-free-for a full 30 days, visit brilliant.org/GEOGIRL . The first 200 of you will get 20% off Brilliant’s annual premium subscription!
Why dont our 02 molecules match but those found in the rings of Saturn? Hmmm? And the floods. Those wernt myths
I Love you @GEOGIRL
As a layperson, I find your lectures to have just the right depth. Your language and explanations of technical terms are accessible, yet I never feel you're talking down to your audience.
Thank you so much! This means so much, you have no idea ;D
We are to clpse to this sin the watwr says this the m45al iro. This wanyns oxulygen and carebon sloqs 5he jpu4rney. 5h4r ptoximity to the sun might be due to carbon
Th4 we3ight of waters is altered by the flora wie it shidts away thebdetrium by timee it might be the swme 2atwr 2ith life ot lightened this wayer
Was mars salt rarios less tjere than here
They should call you "Universe Girl" because you just taught me why the gas giants are located in the outer solar system. I've been into astronomy for a long time but never knew that!
Thank you for another great video. So many so called science videos are barely more than a list of facts (often not even that) The "how do we know?" Part is the only part that transfers real knowledge. You have a beautiful balance of educating and entertaining without talking down to the viewers.
I have come to expect this from you but never want to just take it for granted.
Thank you so much! You have no idea how much this comment means to me! That is what I strive to do and I am so glad it comes across :) Thank you!!
there are so many robot voiced/obviously flawed a.i. science videos popping up lately it's frustrating. all the more reason to be thankful for rachel doing these for us.
@@meesalikeu I know, I have been sucked in so many times by an interesting title on a thumbnail, only to be let down again. I have moved past frustrated to somewhere closer to infuriated. I heard that YT don't count it as a "view" unless you watch for 30seconds or more. I try to quickly hit stop before the 30 second mark then try to block that channel. (I don't know if that 30 second rule is true)
You are right, it does make Rachel's videos even more valuable.
@@spindoctor6385 @meesalikeu a bit late but it may be helpful. The thumbnails on the RUclips main feed/homepage have a 3 dots menu on the right hand side of the title. Through that you can tell RUclips “I am not interested in this video” (you can also specify why) and “don’t recommend this channel”. If you use them consistently you can train the algorithm to show you the type of content and content creators you are interested in and avoid most of the garbage.
Remember that RUclips show you more of what you currently click on, regardless of your subscriptions and past habits. I know because I have a wide variety of interests and my focus changes very often. So if you get tired of what you are being fed start using the “not interested” and “stop channel” feature until you get the recommendations you are happy with.
I loved the way you phrased it! "List of facts." So many people go through schooling thinking of science as a "listing of facts." Then, when one of those "facts" turn out to be incorrect, they think "what do those scientists know anyway?!" and dismiss a bunch of OTHER facts.
Science really is more a "way of asking questions." I love the way she presents the questions!
I know it's hard to believe and weird, just few minutes ago I was randomly asking myself where Water came from . and then Found your video when I opened RUclips.
Haha that is so cool! So glad I could help answer your inquiry :)
Interesting topic - thank you very much for this video!
Of course! So glad you enjoyed it ;D
Congratulations on the sponsorship! And thanks for another very interesting video!
Does the moon have a lot of water locked away in hydrated minerals as well? If not, is it just that the moon has lost all water that was once there to space because of the lack of atmosphere?
Also, would it be possible to do an update to this video once the findings from Osiris-rex are announced because I think what we find from that astroid sample may help us better understand this subject. Thanks!
7:48 I _think_ I get what you mean - the initial material was dehydrated minerals and at a later point water was 'brought in' from outer areas of the solar system where hydrated minerals were more stable and it was transferred from the hydrated non-Earth minerals to the dehydrated material that eventually formed Earth. Something like that?
Great video, as always. You’re really dialing in your method of delivery with these videos. And as an audience member, who has some knowledge of a bunch of different sciences, I really enjoy the level at which you teach and explain. Looking forward to more of your videos up and coming, especially the one on early tectonics. I didn’t realize that you were a geochemist before this. And I can see why you talk so much about isotopes. It’s very interesting stuff
Thanks or the video. I read somewhere a few years ago that Saturn's rings have been found to contain water with a very similar isotope ratio to that of Earth's. That is mind-blowing if true - as it suggests a common external source during the formation of the solar system. I need to find the reference for it.
I don't think you're going to get any complaints from the astronomers on here. 🙂 You did a nice job covering the parts of the nebular hypothesis which apply to this situation.
I always have to warn my students that, "We're reasonably confident about this based on current observations, but we could encounter new data which calls for a revision." Yes, the question about the origin of Earth's water has evolved since I was in college! If it makes anyone feel better, one of my college professors told us that when he did his doctoral presentation, virtually everything he said to his thesis committee about Saturn is currently known to be incorrect! At the time that he told us that, he was very excited, along with the rest of his team, to see Cassini successfully launched... and we all know that the Cassini mission caused everyone to revise what they knew about Saturn all over again! 😂
Edited: slight edit of spelling
Thank you! And also that's so true, we always have to be ready for revision based on new information, but that's what makes science so exciting! At least to me :D
@@GEOGIRL It would be boring if no one ever discovered anything new! 😊
It has an unfortunate effect on introductory level astronomy textbooks, though.
@@kerriemckinstry-jett8625 Haha oh yea that's true, gotta make sure you get the most recent edition of the textbooks I guess lol ;D
@@GEOGIRLYes... but telling students to drop $150 - $250 on a brand new textbook for an introductory level course which will become obsolete in 6 months to a year doesn't feel good. 😬
Fortunately, there are decent OERs which do get updated more frequently than most textbooks because they're digital, but I constantly have to revise what I say on each topic. This is good, it means people are exploring the universe. 🙂
@@kerriemckinstry-jett8625 True, I think it is absurd how expensive textbooks can be!
I have heared that many exo-planets that have been detected are gas planets close to their star. This goes against the previous held theory that gas planets form in an area further away from its star.
Its much easier to detect large planets close in than far out so theres an element of self selection. Then theres the fact that planets move. It's thought at some point early on Saturn and Jupiter migrated inwards and then out again. We may just be seeing solar systems where the Saturn and Jupiter equivalents are in the stage of being close to their star
I think you are talking about the so-called hot jupiter class of exo-planet. Their discovery has been merely due to the early and limited detection methods available. Humanity's journey for studying exo-planet is still young. As newer tools, such as JWST, are being rollout, other types of exo-planet will come up more.
Also a theory that all planets are gas giants... until solar wind blows them off. Thus snapshot of Sol-system (us) when very much younger would reveal 🌎 as a 🪐
The quality of your content has improved a lot. I don't know if it's me but you sound and look better. Keep up the good work! Greeting from Chile
Thank you so much! I have actually been playing around with my camera and microphone set up a lot recently, so I am happy to hear that it seems to be working :D
@@GEOGIRL It sure looks better :)
Your sputtering definition was correct (I did a lot of Mars science in my undergrad). Essentially solar winds can ionize particles in the upper atmosphere where they can be carried away by solar winds and/or go on to knock a bunch of other molecules around which will get carried away. This results in atmospheric loss which in turn leads to water loss.
Great Job! Thank you for your time, dedication and clarity.
Thank you so much! :D
thank you Geogirl.
Amazing video! Your channel is criminally underrated!
Once again, great job, Rachel! 😄
Thank you! :D
12:47 Why would Earth's primordial atmosphere be H rich if the accretion disk was volatile poor close in to the new sun? Your doubt over that scenario is warranted.
Another brilliant lecture very interesting thank you geo girl
Earth's water is too heavy, but heavy hydrogen would be in higher concentration in the inner solar system because the lighter molecules would float to the outer solar system in higher concentration. Could that account for the difference of isotopic signatures?
What a great question! I am not sure, but I would assume that the water absence in the inner solar system during planet formation was such that all H isotopes (light and heavy) were transported to the outer solar system. Also, I believe the transport of water to the outer solar system was more about volatility than mass. And if I think about the impacts that either came from asteroids or comets from the asteroid belt or those that were 'soaked' in solar wind, I would assume that those contained a non-preferential mixture of light and heavy hydrogen since I don't think the mass difference between hyodrgen and deuterium would've affected their formation processes, but I am not sure about that. Because on the other hand mass is a major part of planet accretion due to the gravitational pull/mass relationship, so I imagine mass-dependent fractionation of isotopes might have been involved... I am just not sure if the physics of space work the same as those on Earth in that way... Any astrophysics reading this, please comment in this thread! Tell us your thoughts on this, I am super curious now, thank you! ;D
There is also the question of where the planets formed in the early solar system there are some signs that the planetary disk was a lot more wild and wooly than it is now.
Nice stuff
Hey, that is my T-shirt!
I didn't know there was that much water locked up in hydrated minerals. Very interesting.
I didn't either until I was researching for this video and I am so surprised it is so much! So cool! :D
Thanks, interesting topic. In order to throw even more complexity into this, there’s the idea of planetary migration although I’m not sure if it’s effected the rocky ones. Also that the distribution of planet sizes in our solar system is not typical based on increasing exoplanets being studied.
Creation stories often have the water first and dry land created later. Maybe we’re getting closer with our understanding.
Do we know about the hydrated silicate volumes in the crust/"mantle" of mars ?
It may have lost its surface water, but still have entire oceans worth of h2O locked in its subsurface minerals.
Also, on early earth, we had little to no atmosphere to shield us from the solar wind (atomic hydrogen) so while earth cant hold on to light hydogen, it was still very abundant in our early "atmoshere" because it was delivered constantly from the sun.
That may offered some assistance to the idea of magma ocean generated h2O.
Thanks for the video
Your videos are so amazing. I never knew geo science was so interesting until I discovered your channel. Thank you so much. 😍
Thank you so much! I am so glad to hear that, that made my day! ;D
14:56 "Hydrodynamic escape" - yeah.... that phrase hides not a lot of meaning. All it means is that water escaped, but _why_ would water escape Venus? I always find Venus to be problematic in discussing the solar system.
Lol you caught the one thing in the video that I brushed over because I couldn't find an explanation of why venus lost its water that I understood well enough to relay to a camera haha 😂 If there are any astrophysicists that study venus who read this comment, please tell us why! Thanks! ;D
Thank you for a fascinating look at where water might have come from -- while astrophysics is not your direct specialty, your expertise in isotope concentrations and geo knowledge yields observations not easily found anywhere else!
Fascinating video, thank you!
Thanks! So glad you enjoyed it :D
Geo Girl is amazing! Love these fantastic videos! ❤🎉😊
Thank you so much!
Good video, not too long but long enough to have real content. And while water always gets all the attention, I find the question _How did Earth end up with so much _*_nitrogen_*_ ?_ almost never is discussed. And in the question of life on planets, nitrogen is just as important as water. All living things are made from nitrogen compounds. Nitrogen as N2 or as ammonia would have, like water, been pushed outwards by the young Sun.
Mars seem to be nitrogen poor, compared to Earth.
Venus' atmosphere also has nitrogen, and I think a good discussion can be had that both Venus and Earth were radically changed early on by impacts. Venus ended up rotating on its axis contrary to the other planets and its own orbit, a sign that something big happened.
This is a great point and an awesome idea for a future video! Thank you! I just briefly looked into it to answer this comment somewhat intelligently and from what I read, it seems that nitrogen gas (N2) is heavier than voltailes common in the gas & ice giants of the outer solar system (such as H, He, & H2O vapor). N2 apparently is also more stable in its gaseous state at higher temperatures than those other volatiles; thus, it remained stable in the inner solar system and became a large part of the atmospheres of rocky planets. I will certainly look more into this for a future video though! I think it will be a really good one considering the underrated, yet incredible importance of N for life! :D
REALLY good video on this topic, Girl!
Thank you! So glad to hear that :D
You are fantastic@@GEOGIRL. I'm so thankful for contributors like you who read the "papers" and interpret for us!
i always wanted to know more about this. thanks for explaining so clearly for us. it's fascinating how earth has so much water, well at least so visibly on the surface anyway, versus the other planets and moons in our solar system and you cannot help but wonder why. i can see how we still do not know how that happened for certain, but at least the mechinisms seem pretty clear. it was probably a mix of all of them.
To me, GeoGirl has offered Probably one of the Best, if NOT the Best, Explanations of where Water on Earth came from BUT the FACT still Remains, "Scientists don't know where the Water came from." It is still just Theory.
Yep, everything I discuss regarding Earth's history is of course hypothesized or theorized not 'known'. That's always important to remember when studying our planet's and solar system's history :)
@@GEOGIRL -- THANK YOU GeoGirl.
It will be great to hear how thr Osiris Rex sample will shape up in comparison to Earth.
Yes! So excited :D
Any sudden injection of massive amounts of water, in any form from space or the sun, would cause a new oscillation until a new harmony of water and earth deep crust has been reestablished. This could be the cause of the recent glacial oscillation on Earth.
This was amazing... Do an hydrology playlist please.
I am from Africa: Ethiopia 🇪🇹 where the longest river in the world which know as Blue Nile (Abbayaa) is started. Say some thing about this river For your yutube family thanks ❤🎉
very cool video and excellent topic thanks :)
I never thought about the substance of solar wind before. When you said that it was mostly hydrogen, it blew my mind, but made total sense!😮😅
I know right! I never thought about it before either! When I was reading about it for this video I has that same realization like "oh that makes so much sense" lol! ;D
Another great video. Perhaps you remember the parable of the Blind Men and the Elephant as retold in the poem by John Godfrey Saxe -- And so these men of Indostan / Disputed loud and long, / Each in his own opinion / Exceeding stiff and strong, / Though each was partly in the right, / And all were in the wrong! // I often wonder if all the theories taken together are more right than any single theory on its own. Love your work.
Rachel, Thank you very much for this video 📽️. I think a long time ago I asked you about this in one of my early comments. Excellent job 💯!
Thank you! And thank you for commenting that! I had a lot of people ask me this question in comments, and it took a while for me to learn enough to make this video, but I am so glad I did because now I have such a better understanding of it as well :D
Just a comment about the Hydrogen content of a primordial earth during its formation ... Atomic or molecular hydrogen will escape from the atmosphere into space when the molecules accelerate to escape velocity from heat. The molecule is light enough that escape velocity can occur - unlike heavier molecules like N2, O2, or CO2. A heavy molecule like CO2 also has additional degrees of freedom for motion so that it can absorb more thermal energy without necessarily accelerating the translational motion. However, this is all temperature dependent, which is then dependent on solar radiation, the temperature of the earth surface, and convection mixing. All of this changes in cold places like the poles, or the night-side of the planet. I think this is also why H2 could actually exist on a planet like Mercury, since the night-side of the planet is not heated by the sun, and it stays that way permanently. Even so, it seems unlikely that enough H2 could exist in the primordial atmosphere to mix with SiO2 minerals to create the water we see on earth today. But, enough of it might have mixed in to lighten the D/H isotope ratio.
This is such helpful information! Thank you :D
Also important to remember that accretion of planetesimals is a response from a collapsing cloud of gas to lose the angular momentum which inhibits further collapse under gravity by the formation of angular momentum sinks be it planetesimal clumping/conglomeration, heat generation via collisions/friction or plasma outflows from the central ionized accretion disk around the forming protostar.
So the atmospheric environment the Earth and the other rocky planets would have at this point formed in would be pretty heavily saturated as the flow of hydrogen gas continues to rush inwards to form the Sun. So this bulk flow would be fairly "high density"(astronomically speaking) hot hydrogen and helium gas with traces of other elements which today composes the bulk constituent mass of the Sun.
Planet formation is still a bit contentious of subject as there is several camps of planet formation that have arisen which relate to the direct mechanisms responsible for planet formation as well as the timing of these events.
That said to address your confusion on where this hydrogen atmosphere was coming from a key point to keep in mind is that accretion is powered by gravity and the conservation of angular momentum. In this sense matter in an accretion disk is falling towards the center of mass of the system but in order to do so angular momentum must be shed either through the clumping of matter to form clusters which high angular momentum or through the release of momentum as kinetic energy and heat and in the inner most ionized region magnetohydrodynamic plasma outflows
In this sense the bulk of material that is forming planets is forming a dense inflow inhibited by angular momentum so any means which can enable this net angular momentum transfer to related sinks is going to be favored energetically whether it be collisions chemical reactions or planetary accretionary inflows forming around large planetesimals that have already formed.
Today this hydrogen dominated mass inflow now makes up the bulk composition of the Sun while the solar system's total angular momentum is found not within the Sun but the various planetesimals with the more massive the orbiting compact bodies carrying a greater fraction of this total angular momentum, i.e. most of the solar systems angular momentum is contained in Jupiter. This transfer of angular momentum as necessary in order for the Sun to form and thus planets and the Sun formed relatively simultaneously. Does this help resolve your question?
Mars water scenario was likely driven both in part due to atmospheric loss/outgassing but also due to a considerable fraction of Mars's water having formed into mineral hydrates.
In terms of rock hydration some pretty insightful details can be found in this paper on hydrous mantle plume upwelling(www.nature.com/articles/s41598-019-43103-y) which suggest a potentially deeper role in thermodynamic cycling on Earth where the interior temperature of the planet moderates the rate and timescale of mantle hydration/dehydration. I can't help but wonder if mantle hydration might even provide an explanation for what force is directly powering plate tectonics given recent evidence in the case of seismic tomography about the Mantles far more dynamic inhomogeneous structure.
As for that larger debate on timescale there has traditionally been relatively steady state models as those can be readily computed but there is a strong growing body of evidence both from within the solar system and from elsewhere via observations by Large radio Interferometry which suggest planet formation is a much more rapid disequilibrium process dominated by chaotic accretionary flows (turbulence) where eddies within the flow can in essence undergo direct collapse to serve as spontaneous angular momentum sinks.
In our solar system the best evidence for direct collapse laying a much greater role (note that there is still strong evidence for accretion in the case of giant planets) comes from isotopic constraints on the timescale for which Earth must have formed to retain Nitrogen gas as Earth's nitrogen isotope ratio appears to be a close match for the nitrogen ratio of undifferentiated chondritic asteroid material rather than the isotopic mix recovered by comet sample collection missions thus far. There is also fairly powerful evidence in the Kuiper belt fossil from the classical KBO observed by New Horizons 486958 Arrokoth as it seems to match the expectations for an object that has been frozen part way through direct collapse at the time when the solar nebula accretion flow ceased.
With Long Baseline Radio Interferometry we have observed what appear to be planets that have formed far too soon for accretionary models to explain as well as a diverse array of highly complex unique and dynamic flow patterns within accretion disks around young protostars. Moreover we have even witnessed time variability in many of these systems with some intense bursts of activity that may in fact be this process being caught in action from far away while others appear to be direct evidence of collisions.
In fact earlier this year(I think?) there was a fairly fascinating but also somewhat chilling observation that the light outbursts from nearby accreting protostars appears to occur in discreate bursts which based on the energy are equivalent to several Jupiter masses of material infalling all at once. If such work is continued to be reproduced then there is a good possibility we may have flipped things around and its more the case that rather than stars building planets giant planets build stars.
A Colloquium speaker some years back when I was in grad school discussed an interesting calculation where when accounting for fluid dynamics in the dense cores of molecular clouds be estimated that the effective Jeans mass for direct collapse might be closer to 10 Jupiter masses which would be orders of magnitude less than back of the envelop/ spherical cow model calculations would suggest. The recent JWST result finding numerous objects around this same giant planet size range might be the strongest evidence that this model is right.
OMG, thanks so much for all this info! This is super helpful, I am so glad you put this here in the comments so hopefully many people can reference it for more in depth physics info on this topic! :D
@@GEOGIRL Glad I can help it is a tricky topic and one which is still unresolved in many areas with lots of nuance that I haven't really seen addressed outside of papers.
There are for instance multiple accretionary models some which resolve challenges with the conventional long timescale accretionary models for example but I figured that would be too complicated for this purposes as at this point the question of disk instability direct collapse and accretion is probably a case of both.
Then another point of discussion which I left out for the case of water is the lunar formation impact event and how that would effect the Earth. In early models this was cited as a reason why Earth would need a secondary source of water however its worth noting that our models haven't reached a limit in resolution where the behavior stabilizes with higher and higher resolution models showing a consistent trend of reducing the timescale for the impact while increasing the range of possible configurations and the likely overall amount of violence of the event. In essence some of the newer models involve a far more direct collision that more or less volatilizes the proto Earth and Theia however the high surface tension of the molten emulsion of primarily silicate fluids mostly remain gravitationally bound with many of the droplets of molten Earth falling back to the newly formed Earth with momentum conservation dynamics kicking into play in governing the large scale behavior of the post collisional state.
This fluid dominated behavior may be relevant to the whole water situation as we know that under high pressures water in a supercritical fluid state(i.e. where it exists as both a liquid and a gas) and silicate magmas form a stable emulsion which might help retain water.
Additionally if when the fluids separate out after settling then the temperatures would likely still be more than high enough for a water vapor layer to become supercritical as supercritical water exists naturally in the Abyss in hydrothermal systems where high enough temperatures and pressures exist simultaneously. In that case when said supercritical fluid cooled it would be expected to naturally decompose into a ratio of liquid and gas states meaning you can get a liquid water ocean before any kind of solid crust could have formed.
In this sense in the hours after the collision as the globs of rock in orbit coalesce into a still molten Moon Earth would already be submerged under a hot glowing ocean of supercritical water and steam.
This wouldn't be too different from what Venus has going on with its own supercritical carbon dioxide ocean just it would be far hotter and denser with a mix of volatile gases not just water.
On a related note an understanding of what kinds of exotic chemistry can occur in several thousand kelvin supercritical water silicate magma interface could in some only partly crazy way be an interesting environment for abiogenesis research given the finding that basaltic glass is capable of spontaneously catalyzing the formation of several hundred base pair strands of RNA.
With this I can't help but wonder if some more exotic analog process exists at extreme pressures and temperatures? Material science is showing some interesting kinds of exotic chemistry goes on in the high pressure domain so this might not be as crazy as it seems since this could give you a maximal surface area for rock water fluid interface reactions.
Worth remembering just how much water there is in the solar system. Hydrogen and oxygen being the first and third most common elements and when combined become extremely stable. How it gets distributed through out the solar system is still a developing subject , particularly with regard to the migration of the planets to their present orbits.
yes, it's almost beyond belief how much more water there is than what we thought not so long ago. and its very exciting because of course that is such a basic need for life as we know it. not only can we use it exploring our own solar system, but it must make possible life around the universe even more likely than we imagine.
To use, the water looks significant, but if you consider it covers "only" 30% of the surface, to "only" a depth of 4km (vs an Earth radius of about 6000 km), another way of looking it is that it's really scarce? We have this thin film of water, just like other rocky planets may have had thin films of water. And it might not take that much for us to lose it.
I visited Corpus Christi, Texas to view the annular eclipse last week, and I couldn't stop staring out at the ocean and thinking about how all of that water came to us.
Perfect timing!
That's awesome! So glad you got to see the eclipse, it was so cool :D
DESTINATION US, Next Year for the Total eclipse follow up!
yay! I always hoped you would do a video on this subject, and you did a great one! thank you
....my guess is that Earth's stronger magnetosphere held the water here, where Venus and Mars didn't have that advantage; Mercury does have a decent magnetosphere, but is too close to the Sun ....but even if there was liquid water on Venus and Mars for a while, without good magnetospheres life could not develop due to radiation
Does Venus really lack a magnetosphere?
If that's true, it is very surprising to me.
If anything I would have expected Venus to have a more potent magnetosphere than Earth does!
Hmm, I guess I'll have to research this now.
I had assumed Venus water went to H2SO4 in atmosphere and is too hot to have in fluid form...
How do you incorporate fate of water with the formation of the Moon after glancing impact with pre Earth the imparted spin to Earth and fortified the size of the core. That was before the great bombardment might have rewatered Earth...
You may have noticed some Earth sized exoplanets are water worlds... in about the same relative position in the goldilocks zones... could Earth have started on the path to being a water world before the Moon forming impact?
You might check out Bruce Betts astronomy classes... they are a few years old now... but they did cover Moon-Earth formation fairly well.
Resident physicist here 🫡
So glad to have you! Please feel free to fill us in on the stuff I left out ;D
@GEOGIRL I think you covered it very well! This is a geology channel so the focus is on Earth of course, but recent cosmological studies are showing that water-y planets are more common than we thought, and the processes of water formation you talk about here apply to far reaches of the universe.
Astro Girl? Space Girl? Now that would be fun! 😊
Hydrogen most common element in universe, oxygen is 3rd most common. That's where water comes from
@@punditgiAstroGirl has that retro 50s vibe 🚀 👩🚀 💫
Thanks a lot for this explanations!!! So interesting!!!
Love your channel.
Seems like every couple of years there's a new story about possible signs of water detected on Mars
Yea, well it seems we keep finding it in different regions on Mars, but it is mostly, to my understanding, trapped below the surface in ice or very saline brines. I'm not sure whether fresh water has been found on Mars, this is probably a good time for a mars scientist to enter the chat ;)
Very interesting video, as always. As far as I have understood, Mars and Venus have very weak/non existent magnetic fields and Solar wind stripped most of the water form those planets, unlike on Earth.
I am convinced that Earth is a chthonic world - the rocky core of a mini-Neptune that used to be between the present orbits of Mars and Jupiter. It was smacked by Theia, blowing off the majority of its gas envelope, splitting it into three primary objects - Earth, the Moon, _and_ Mars, and leaving debris which is now the asteroid belt. I admittedly have zero evidence to support my hypothesis. It's just a totally awesome origin story.
Great video! I've always wondered what determined the ratio of ocean water to mantle water. If it were even slightly different, the ocean could overtake all the continents or disappear altogether. Fermi Paradox anyone?
In other news, I recently learned that Earth's moon likely had an atmosphere with twice the pressure of modern Mars for a brief period of time, and probably some liquid water as well 👀 I wonder if Geo Girl has a video on it.
Sponsor 🎉 GEO Girl is moving up !
🎉:)
Why isn't creation considered a hypothesis? Sputtering explanation for lack of water on other planets, is exactly why water wasn't formed through material processes on earth.
Basically, In the vacuum of outer space, water would turn into vapor and evaporate quickly. Due to the lack of atmospheric pressure, the low temperature, and the absence of gravity, water would instantly boil and then dissipate as vapor. The extreme conditions of space cause liquids to boil away rapidly without transitioning through a liquid phase.
In space, the water vapor that evaporates would disperse into the surrounding vacuum as individual water molecules. These molecules would not coalesce into droplets or reform as liquid water due to the absence of atmospheric pressure or gravitational forces that would normally facilitate the condensation process.
Nile Red has a video of extracting water from Epson Salt and how 60% of the Magnesium Crystals is ancient water.
Hi Rachael, again and again you're expand my geo/astro knowledge. I like the fact that you presented more-then-one possibility, because life is like that sometimes also. I had a chuckle when you mentioned "Astro Girl." Starting 1952, there was a cartoon that was produced in Japan, shown on American TV, called "Astro Boy." I can visualize you and he teaming up, zooming around the world, fighting evil and doing good for mankind (is that still a word these days?). Also, I wanted to mention that Matt from the NHSM, sent you a message via your website, but hasn't yet received a reply. It's about giving a Zoom presentation for our monthly Fossil Club meeting. I hope you can do it :) g.f.s.
Oh thank you for letting me know! I am so bad at checking my website messages, I will go check and try to get back to them :)
Thank you for this amazing video! It's the most clear explanation I have found about water origins on the net. I am not scientist, that's probably why there is something I quite not understand yet: I get that volcanos degassed hydrated rocks from accretion that were in the mantle, but about asteroids, if they are balls or big pieces of rock and ice, wouldn't the ice in them vaporize when entering the Earth's atmosphere? I am not sure how could they make it into the mantle keeping their water and then be degassed by volcanic activity. Any thoughts?
You are a very good teacher, madam 🎉🎉🎉
At first I was like "well, I'm pretty aware of all this thanks to everything I read", but then I was like "wait, swallow your pride, this is GeoGirl, you're certainly going to learn something".
And I did.
Many things. 🙂 🙂
Personally I favor all of those processes, (to one degree or another) for how Earth got it's water.
The question for me is what percentage each of those processes delivered to us, and when?
I also think the we are still adding material (of various kinds) to this planet every single day.
Obviously nothing like the amounts at the beginning, but the process IS still ongoing.
So study of things like meteorites, and asteroids is (I think) very geologically important!
Thanks for the great video.
i am so here for that mars content lol.
Really interesting video. I dont know enough about this my self but could early earth had changed that heavy Hydrogen to light at all? if not is small chance encounter with and interstellar object that brought water enough to give earth a good portion of its water?
1:04
A funny and relatable comic:
Wife: Honey, come to bed.
Husband: I can't yet, it's important.
Wife: What is it?
Husband: Someone is *WRONG* on the Internet!
Rachel I still don't get after watching this video which one of these hypotheses which one is the most likely? Also will taking a course on brilliant help me better understand the math and physics involved on the obstacle courses on the show American Ninja Warrior if so how
Very interesting! Thanks! I hadn't really thought so much on the how, I was always thinking that Hydrogen and Oxygen make water, but never the mechanisms, and I am glad I have found out now the variety of ways it could have came to be.
I didn't assume that you would get so much into the intricacies of mass fractionation of isotopes to decipher the evolution of our atmosphere 😂. Loved this video. Keep making these geology videos for us 😊 ❤❤
Hey anytime I can get into isotopes, you know I will lol! ;D
amazing
I remember learning that greater air pressure increases the boiling point of a substance. So when solar winds got rid of Mars’s atmosphere, air pressure would’ve dropped significantly, allowing for there to be more water vapor due to a lowered boiling point, which would’ve then been blown off by solar winds. The only caveat to this might be that if greenhouse gases were removed during atmospheric destruction, that would’ve led to colder temperatures, making it less likely for water to vaporize despite the lowered boiling point. So maybe that’s why there’s still ice left over? 😅
Astronomy is Geology, just on another planet.
There was once the direct collision hypothesis, with Theia being up to 50% ice. Or has that been debunked?
I think the much more important question is "what happened to Mars and Venus' water?"
I think it far more likely that the underground lizard people mined the deuterium millions of years ago to power their fusion reactors ;D
Dr. Geo Rocks it out again! Dr. J =)
Proto Dr Rachel defends her dissertation in just a few weeks! Wish her well!
Mars defn had a lot of water once. That's why it's red: it's covered in rust, which needs water to form.
Thanks!
Would extra protons (H) and neutrons come from radioactive decay of heavy elements near the earth's core, which keeps the inner earth hot and molten? Would these skew the heavier isotopes of the O and H in water that came from volcanos?
Earth probably gained its water from many different sources, all of it being mixed and geologically processed for billions of years, making it impossible to figure out where it came from by analysing its isotopic composition.
Ahh, at last: The origin of water; from Geo Girl 👍👍
Problem with the deuterium excess in the asteroid belt: I know the hydrogen isotope composition of asteroids and comets have been used to argue about the origin about the Earth oceans, but in contradistinction to the Earth oceans, the asteroids and comets have been exposed in billions of years to the solar wind and, in some comets, interstellar cosmic rays. According to my amateur reasoning they *_should_* have a deuterium excess due to vaporization and ablation. C.f. the deuterium excess in the atmosphere of Venus! As far as I can reason, the only valid way to determine water content of a certain age on a certain solar system body, is water content in zirkon crystals, whose age has been determined within a certain pretty narrow time interval with a certain degree of confidence.
sweet
Hydrogen is the most abundant element in the universe for a reason and hence all molecular compounds of hydrogen will also be the most abundant(more or less).
The planets distribute their makeup according to centrifugal forces and the position of the earth is about where oxygen would settle out. They would then start to form hydrogen compounds(e.g., water). All the theories are likely correct to different degrees.
I'm not liking any of the possible explanations. It could be something more outrageous. During the later stages of stellar fusion, after the hydrogen fuel is used up - heavier elements fuse until you get to iron, and even much heavier than iron in the case of a star that goes supernova.
One of the steps is C + He --> O. And if for some reason there was a large amount of oxygen that didn't fuse to something heavier before a star exploded, then a massive amount of Oxygen would spew into space - and if it found its way to a cloud of hydrogen somewhere else in the galaxy, you would have a massive amount of space water available.
I wonder if we could use certain fractionization products to determine if life exists on exoplanets, such as carbon 12 vs 13?
Wait, will outgassing eventually dehydrate the mantle and cover Earth with all those extra oceans worth of water, or will the planet cool and all geological activity cease long before that can happen?
It's my understanding that Earth will cool to a point that tectonics stops before the mantle completely dehydrates (besides the tectonic plates that subduct continuously bring down more water to the mantle). :)
@@GEOGIRL Oh ok, awesome! I didn't consider water getting back into the mantle too. It's like a complete cycle then. Thanks for your answer!
Another mystery is how Earth got a mostly nitrogen atmosphere. N2 doesn't seem to be very common around our solar system.
Please make a video geomorphology
Diderot invented the encyclopedia. I hope you can come up with a modern equivalent, for the geosciences.
People do not have a general grasp, of what should be called essential knowledge.
Excellence, as always.
It was me I was running a bath & I got distracted by next doors dog dropping a 2 ft hemp rope on our patio!!
The solar wind added one meter of water to earth over 4 billion years, there are at least three ways to calculate this and you could do a video on this.
The real source of the water is stellar outbursts. A 12,000 year cycle of black mat layers with nanodiamonds and tektites.
I came into this video with ice meteorites mind, but i wanted to see what she said.
If I'm following correctly we still don't know (?)
Haha basically... Well we know the contributing processes but we don't know at what ratio they contributed to Earth's total amount of water. ;)
@@GEOGIRL Thanks for taking the time to reply. I had to re-watch the video to make sure I didn't miss something and I still wound up scratching my head. So I guess a more correct title should be "& How Will We know?"
Hability major point!
I wondered why old rocks would be on the surface and not the interior.
I think an initial ammonia atmosphere is more likely than a hydrogen one.
Well the atmosphere was largely composed of N compounds, namely N2 and ammonia, as well, but when I say hydrogen-rich (at least based on my understanding), it means relative to today, not necessarily hydrogen-dominant, if that makes sense :)
Maybe Theia had an excentric orbit, basically being a massive comet. And when it hit Protoearth, the resulting (double) planet inherited all that juicy goodness.