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We May Have Jupiter To Thank For the Nitrogen In Earth's Atmosphere

Posted by Soulskill on from the jupiter-never-forgets-our-birthday dept.

An anonymous reader writes: Nitrogen makes up about 78% of the Earth's atmosphere. It's also the 4th most abundant element in the human body. But where did all the nitrogen on Earth come from? Scientists aren't sure, but they have a new theory. Back when the solar system was just a protoplanetary disk, the ice orbiting the early Sun included ammonia, which has a nitrogen atom and three hydrogen atoms. But there needed to be a way for the nitrogen to get to the developing Earth. That's where Jupiter comes in. During its theorized Grand Tack, where it plunged into the inner solar system and then retreated outward again, it created shock waves in the dust and ice cloud surrounding the sun. These shock waves caused gentle heating of the ammonia ice, which allowed it to melt and react with chromium-bearing metal to form a mineral called carlsbergite. New research (abstract) suggests this mineral was then present when the Earth's accretion happened, supplying much of the nitrogen we would eventually need for life.

46 comments

  1. Not the only planet by Anonymous Coward · · Score: 5, Funny

    We also have all this damn methane thanks to Uranus.

    1. Re:Not the only planet by Anonymous Coward · · Score: 0

      I thought indole, skatole, and thiols (sulfur-containing compounds), as well as the inorganic gas hydrogen sulfide would be associated with this kind of blask hole?

    2. Re:Not the only planet by Anonymous Coward · · Score: 0

      Thanks for that! Haven't laughed that hard for some time... I wish I had some mod points about now.

  2. Saturn pulling Jupiter by Anonymous Coward · · Score: 0

    How does Saturn coming in close to Jupiter cause the pair to migrate away from the sun, would they not just both get pulled in closer?

    1. Re:Saturn pulling Jupiter by Anonymous Coward · · Score: 0

      No. The pull towards the Sun was caused by gas on the planet's orbit. With the gas gone, the main force left is the expansion of the universe (7% every billion year) which is pulling them outward.

    2. Re:Saturn pulling Jupiter by Anonymous Coward · · Score: 0

      Planets, especially of comparable size, will tend towards orbits that form resonance with each other. Even though gravity is always pulling things closer, when you have effects in sync or out of sync with something cyclical like an orbit, you can push and pull things in less intuitive ways, and things can setting to a point where their orbital ratio forms a ratio that causes the pushing and pulling to average out over a complete cycle.

      Jupiter and Saturn by themselves can not just migrate further away, as that has issues with conversation of angular momentum. But if Saturn moves closer to Jupiter, and for example fell into the 2:1 resonance, the mutual influence would lessen, and they could become more susceptible to interactions with other smaller bodies. The idea that Jupiter moved inwards then back out would have the back out movement come from flinging smaller planetoids out of their orbit and exchanging angular momentum.

    3. Re:Saturn pulling Jupiter by Immerman · · Score: 4, Informative

      Nothing ever gets pulled closer, except that something else gets thrown further away in equal measure, anything else would violate conservation of momentum. This page give a bit of an overview: http://www.boulder.swri.edu/~k...

      As I understand it the idea is that they were acting within a relatively dense gas-and-asteroid cloud rather than the modern vacuum. Jupiter was moving inwards as it scooped up gas and asteroids from the inner system, launching most of that material into the outer system. And miniscule Saturn was towed along in it's wake. Eventually the orbital resonance with an encroaching Saturn slowed and reversed Jupiter's motion, at which point they began scooping up the detritus that had been thrown outward on their inward journey and hurling it back inward again while they moved outwards, eventually moving outwards far enough that they could start scooping up the previously undisturbed outer-system cloud and hurling it inward, moving them even farther out than they had originated. And of course Uranus and Neptune had meanwhile been busy throwing more material inwards from the far-outer system as they performed their own migrations, further fueling the outward migration of Jupiter.

      Think of it like a gravitationally powered rocket engine - every asteroid that does a gravitational slingshot around Jupiter transfers just as much momentum to Jupiter as it does to the asteroid.

      Eventually Jupiter's orbit stabilized when it ran out of enough outer-system detritus to propel it further outward, while orbital resonance continued to propel Saturn even further outward at the expense of propelling Jupiter slightly inward, solidifying the new orbital position.

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
    4. Re:Saturn pulling Jupiter by Tablizer · · Score: 1

      The idea that Jupiter moved inwards then back out would have the back out movement come from flinging smaller planetoids out of their orbit and exchanging angular momentum.

      But Jupiter is massively massive, to misuse English. It's hard to believe all those small asteroids and junk would have enough bulk and momentum to make a difference on it.

      Was there a lot more junk flinging around back then? I don't get it.

      --
      Table-ized A.I.
    5. Re:Saturn pulling Jupiter by Tablizer · · Score: 1

      I don't believe the expansion of the universe makes any notable difference on the scale of a solar system.

      --
      Table-ized A.I.
    6. Re:Saturn pulling Jupiter by Anonymous Coward · · Score: 0

      This is process is thought to contribute material to the Oort cloud and far reaches of the solar system. While the planetoids would have a lot less mass, they would have gained a lot more speed. Jupiter could lose enough momentum to move from ~2 AU to its current ~5 AU position by marginally ejecting just two Earth's worth of mass out of the solar system, or slightly more mass to the outer solar system. A lot of mass is expected to have been thrown out as orbits settled and cleared out junk, and it might also help explain why Mars is smaller than Earth and Venus.

    7. Re:Saturn pulling Jupiter by Anonymous Coward · · Score: 0

      Why not? If after a billion years a large-scale structure of 1.00e22 meters expanded to 1.07e22 meters, then each individual meter along the way expanded to 1.07 meters on average.

    8. Re:Saturn pulling Jupiter by Anonymous Coward · · Score: 0

      If every length scale in the universe expanded the exact same amount, there would be no measurable difference, just like how you can do physics in meters or centimeters by just multiplying by a factor. You need a change relative to something else for there to be a change in how things behave (some unitless value somewhere needs to change).

      That said, metric expansion in GR doesn't cause every distance to increase evenly, and expansion will not be noticed between things gravitationally bound or bound by other forces. The expansion is in some naive ways like inertia from the Big Bang, and if forces pulled things together, they will stay together. If you fired a shotgun, the shot will scatter, but if two pieces manage to be glued together strong enough to survive the original shot, they will tend to stick together. This analogy is far from perfect, and accelerating expansion complicates it, but from what has been seen so far, that effect is so small that it is still overcome by forces by things on the size of a galaxy or smaller.

    9. Re:Saturn pulling Jupiter by Anonymous Coward · · Score: 0

      If every length scale in the universe expanded the exact same amount, there would be no measurable difference

      Not if the forces of nature don't scale correspondingly.

      metric expansion in GR doesn't cause every distance to increase evenly

      That's exactly what it does.

      expansion will not be noticed between things gravitationally bound or bound by other forces.

      It won't be noticed between things bound as a solid, but it will be noticed between things bound gravitationally.

      Something like a yardstick isn't affected because if you magically stretch the space between every atom they will go back to their original spacing like a rubber band, releasing a bit of heat. If you magically stretch a solar system, the planets will shrink back to their original diameters for the reason above, but their orbits will stay stretched, and even become larger because the orbital speed is now too large.

    10. Re:Saturn pulling Jupiter by Anonymous Coward · · Score: 1

      metric expansion in GR doesn't cause every distance to increase evenly That's exactly what it does.

      No, it does not. Wikipedia among many other write ups on the topic address this, because it is a common question why galaxies and the solar system. If you don't like Wikipedia or pop-sci sources, classic GR textbooks like MTW's Gravitation spell this out too.

      Something like a yardstick isn't affected because if you magically stretch the space between every atom they will go back to their original spacing like a rubber band, releasing a bit of heat. If you magically stretch a solar system, the planets will shrink back to their original diameters for the reason above, but their orbits will stay stretched, and even become larger because the orbital speed is now too large.

      There is nothing special about gravity versus other binding forces. Inertial effects exert no forces on bound objects, whether bound by gravity or other forces. Expansion due to a pressure term like vacuum energy can exert a force, but o heat is generated in a yard stick, as without any movement, no work is done. You don't get things moving and things snapping back, some sort of oscillation, but just a shifted equilibrium position (if you push on a spring, it moves to a new point, and doesn't snap back unless you let go), but the force involved is proportional to length scale, and effectively zero compared to other forces at the human or even solar system scale.

    11. Re:Saturn pulling Jupiter by Tablizer · · Score: 1

      This seems backwards; I'm missing something. Remember, I'm asking about Jupiter moving back out, not in toward the sun (which the article suggests is from friction with dust etc.). Other objects would have to lose orbital momentum for Jupiter to gain. Jup moving out would push the space junk inward, not outward.

      --
      Table-ized A.I.
    12. Re:Saturn pulling Jupiter by Anonymous Coward · · Score: 0

      Flinging things outward will tend to pull the planet outward. The planet can't put the planetoid into an orbit with a perihelion much larger than the planet's orbit, but it can put them into highly elliptical or hyperbolic orbits with much smaller perihelion. The highly elliptic orbits mean the planetoid now has a lot less angular momentum, and the planet gains a little bit and moves to a larger orbit, with a much smaller change in ellipticity. Flinging things inward can have the same effect if you move the perihelion of the planetoid inward, but if the aphelion doesn't increase much, it will keep interacting with the planet until it ends up in some sort of resonance or gets flung out.

    13. Re:Saturn pulling Jupiter by Anonymous Coward · · Score: 0

      So the main reason far away objects in the universe are flying apart is inertia? A.k.a. "we've been lying, space isn't actually expanding, and a naive explosion is a better analogy than a stretching balloon?"

      And actual stretching of space is caused by "vacuum energy", much slower than 68 (km/s)/Mpc, and doesn't even have these units?

      That's totally messed up.

      The "snapping back" was of course just a thought experiment to distinguish systems with an equilibrium position and those without. The absence of an equilibrium (not the type of force) is what decides whether something is affected by expansion of space (a true one, not the misleading cosmological definition).

    14. Re:Saturn pulling Jupiter by Anonymous Coward · · Score: 0

      A.k.a. "we've been lying, space isn't actually expanding, and a naive explosion is a better analogy than a stretching balloon?"

      No, you need to read what was written:

      The expansion is in some naive ways like inertia from the Big Bang, ... This analogy is far from perfect...

      Inertia is involved, but so is expansion of space. It is not the same as just galaxies moving apart in static space, as there cumulative effects on the photons from distant galaxy (e.g. angles between rays). The stretching balloon analogy is still apt, just usually the confusing bit left out is that there is nothing attaching anything to any particular point on the balloon, as there is nothing that causes matter to stay attached a particular coordinate in space. Things tend to stay some place from inertia, but will move when there is a force on them.

      And actual stretching of space is caused by "vacuum energy", much slower than 68 (km/s)/Mpc, and doesn't even have these units?

      Dark energy, typically attributed to some form of vacuum energy, is a like a pressure, so yes, it has different units. The expansion it adds to over large distances is still the same units.

    15. Re:Saturn pulling Jupiter by Tablizer · · Score: 1

      The total angular momentum of all solar system objects remain the same, correct? So if we ignore those flung out of the solar system for now (assuming it's not a signif. factor), if Jupiter increases its angular momentum (moves "outward"), then a good many objects will lose angular momentum to counter. Where did it go? Do many "long orbit" objects that once had a semi-circular orbits now have highly elliptical orbits (as many comets do)?

      --
      Table-ized A.I.
    16. Re:Saturn pulling Jupiter by Anonymous Coward · · Score: 0

      About inertia, I was mainly reacting to this sentence from your Wikipedia link: "For much of the Universe's history the expansion has been due mainly to inertia. The matter in the very early universe was flying apart for unknown reasons (most likely as a result of cosmic inflation) and has simply continued to do so".

      Inertia is involved, but so is expansion of space.

      If that's true, then it would be helpful if cosmological articles would care to split the Hubble constant into its "inertia" and "expansion" components. Maybe they don't bother because it doesn't affect observations like redshift, but it does affect whether a solar system will expand or not.

      Dark energy, typically attributed to some form of vacuum energy, is a like a pressure, so yes, it has different units. The expansion it adds to over large distances is still the same units.

      Then this is why it is messed up. (km/s)/Mpc (or Hz) is the only possible unit for the expansion of space. Anything else doesn't satisfy additivity (e.g. 1e22 meters is 1e22 segments of 1 meter -- you cannot stretch on a large scale without also stretching on a small scale.)

    17. Re:Saturn pulling Jupiter by rmdingler · · Score: 1

      Well written.

      --
      Happiness in intelligent people is the rarest thing I know.

      Ernest Hemingway

    18. Re:Saturn pulling Jupiter by Anonymous Coward · · Score: 0

      If that's true, then it would be helpful if cosmological articles would care to split the Hubble constant into its "inertia" and "expansion" components.

      Because they are one and the same, it is an expansion of space acting like inertia. There is no separation to do.

      but it does affect whether a solar system will expand or not.

      No it does, neither does just old fashion inertia, nor expansion of space affect the solar system. Just as in the case of inertia once the solar system forms, it has overcome that inertia and is stuck together, with a simple expanding metric, there is nothing pinning parts of the solar system down to the space they are on top of, so once together it stays together. There is no force involved with this part. However, for things traveling long distances, like light from distant galaxies, it has to deal with distances between its current position and destination changing in ways proportional to the distance.

      Then this is why it is messed up. (km/s)/Mpc (or Hz) is the only possible unit for the expansion of space. Anything else doesn't satisfy additivity

      It is like you asked someone what is the speed of gravity, and they reply it is an acceleration in m/s^2, then you complain that doesn't add to a velocity. The effects of dark energy is more like a pressure and depends on distance over which you are looking. It is not just a constant velocity per distance, but something that changes with time and distance. You can estimate roughly that the Hubble parameter is maybe ~10% bigger now due to dark energy than it would have been otherwise (rough memory), but that proportion changes with time like the velocity of a ball after it has been thrown.

  3. There is a lot of nitrogen about by Alain+Williams · · Score: 1

    It is the seventh most abundant chemical element by mass in the universe, but most of what was on earth has evaporated away.

    1. Re:There is a lot of nitrogen about by Immerman · · Score: 2

      Yes, but "in the universe" is a much different location than "in the narrow ribbon of proto-planetary material that formed the Earth". Hydrogen and Helium are by far the most common elements by mass, and yet there's very little of either on Earth, due in large part to the fact that they are too light to be gravitationally bound by such a small planet unless incorporated into other compounds.

      Consider that a proto-planetary disc around a star would act as something of a centrifuge, causing stratification by molecular weight, so elements would tend to clump together according to the molecular weights of the compounds they were most stably bound into at that point in time. And anything that changed the stability of those molecules - say heating, or a change in concentration of reactive chemicals due to large bodies causing mixing between cloud strata - would change the preferred strata of said elements as they were incorporated into molecules with a different mass, as well as the mixing itself causing molecules to deposit on proto-planetary bodies outside their preferred strata.

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
    2. Re:There is a lot of nitrogen about by Anonymous Coward · · Score: 0

      Hydrogen and Helium are by far the most common elements by mass, and yet there's very little of either on Earth [...]

      I don't disagree with the gist of your statement, but is there really very little Hydrogen on Earth, by mole fraction?

    3. Re:There is a lot of nitrogen about by Immerman · · Score: 1

      Compared to the percentage in the universe? Absolutely. Otherwise the Earth would be ~75% hydrogen by mass.

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
  4. Thanks Carlsbergite! by StatureOfLiberty · · Score: 3, Funny

    A bit ironic that without carlsbergite we might not be able to pour Carlsberg from a nitrogen tap.

    1. Re:Thanks Carlsbergite! by wonkey_monkey · · Score: 4, Informative

      I'm not sure it's that ironic, since carlsbergite is named after the Carlsberg Foundation, which was set up by Carlsberg's founder.

      --
      systemd is Roko's Basilisk.
    2. Re:Thanks Carlsbergite! by Anonymous Coward · · Score: 0

      Also, that's not irony.

    3. Re: Thanks Carlsbergite! by cyber-vandal · · Score: 3, Funny

      No it's chromiumy

    4. Re:Thanks Carlsbergite! by sconeu · · Score: 1

      Don't touch my Carlsbergite!!!!

      --
      General Relativity: Space-time tells matter where to go; Matter tells space-time what shape to be.
    5. Re: Thanks Carlsbergite! by Anonymous Coward · · Score: 0

      That's way too much chrome for this discussion. Thankfully, the metal didn't bear anything proprietary or we would be paying for our existence even today..

  5. I don't think there is enough chromium left. by Anonymous Coward · · Score: 0

    The assumption would be that the chromium in carlsbergite would remain after the nitrogen is released.

    Not enough chromium around.

    1. Re:I don't think there is enough chromium left. by Anonymous Coward · · Score: 0

      Estimates for the total Earth composition gives nitrogen at around 40-50 ppm by atom count, and chromium at ~2000 ppm. There is plenty of chromium around, even if just going with just the crustal abundance of ~100 ppm.

  6. Re:Fuck this snow by K.+S.+Kyosuke · · Score: 1

    Unless Ganymede gets there first, that is. :-p

    --
    Ezekiel 23:20
  7. Really ? by Felgior · · Score: 1

    I bet they were drinking a lot of Carlsberg !

  8. need? by Anonymous Coward · · Score: 0

    We didn't necessarily need nitrogen for life. It's entirely possible that nature would have found an alternative to the nitrogen-based nucleotides, yet yielding the same function.

    1. Re:need? by Ignacio · · Score: 1

      Wow, not even reading the title. Congratulations, you have reached the pinnacle of Slashdot laziness.

  9. Overconfident Astronomers by Anonymous Coward · · Score: 0

    "Knowing that our own planets moved around a lot in the past makes our solar system much more like our neighbors than we previously thought," says Walsh.

    https://solarsystem.nasa.gov/scitech/display.cfm?ST_ID=2429

    Is there something wrong with the training in astronomy? Why do they so easily jump from one computer model result to "knowing" what happened billions of years ago? Or maybe this is just bad journalism?

    1. Re:Overconfident Astronomers by Anonymous Coward · · Score: 0

      Generally, once you learn that things can move around a lot and still give the same result, it is difficult to assume that things have been static for a long time. Knowing that they probably moved around a lot is not the same as saying this particular model is happened. Plus there has already been a lot of questions that can be addressed by the planets changing orbits during solar system formation, but not if assuming they formed where they are now. Where and how much they moved is still actively discussed, e.g. this model being another one on the pile.

    2. Re:Overconfident Astronomers by Anonymous Coward · · Score: 0

      Each planet is forced to migrate by imposing a small change dv to the orbital velocity along the velocity vector at each time-step.

      http://arxiv.org/abs/1201.5177

      I was wondering what was causing Jupiter to migrate in this model and it looks like it is just coded in. Has anyone been able to create a solar system simulation generating one like ours from the proton-planetary disk using forces between objects?

  10. Not a theory by Anonymous Coward · · Score: 0

    They have a new hypothesis.

    If we keep using theory to mean hypothesis, we can't keep complaining when people treat theories like hypotheses.

  11. Grand Tack by Anonymous Coward · · Score: 0

    The Grand Tack illustrations are funny. It looks like Jupiter went and disrupted the inner solar system, then Saturn came in and dragged J's sorry ass back out. U and N ran away, not wanting to get involved in the argument.

    Look here: 1 2.

  12. In Jupitor we Trust by Anonymous Coward · · Score: 0

    All hail Jupitor.

  13. In My Best Jimmy Fallon Voice by Anonymous Coward · · Score: 0

    "Thank You, Jupiter... For the Nitrogen In Earth's Atmosphere. It's the only element we don't need and has no purpose!"

    (Yeah, I know, nitrogen fixing, dilution of gases, yada yada. It's a comedy bit, let it go!)