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Comets Probably Seeded Earth's Nitrogen Atmosphere
KentuckyFC writes "One of the biggest puzzles of astrobiology is the origin of the Earth's oceans and atmosphere. One favored theory is that our water is the leftovers from a bombardment of comets early in Earth's history. But the ratio of hydrogen and deuterium in the oceans doesn't match the ratio in the four comets measured so far (Halley's, Hyakutake, Hale-Bopp and C/2002 T7 LINEAR). Now a new analysis of the ratio of nitrogen-14 and 15 isotopes in these comets and on Earth places new limits on how much of our environment could have come from comets. On the one hand, the astronomers who did the work say that no more than a few percent of Earth's water could have come from comets. But on the other, they say that the ratio of nitrogen isotopes in these comets almost exactly matches the ratio in Earth's atmosphere. That suggests that while Earth's oceans must have come from somewhere else, Earth's early atmosphere was probably seeded by comets."
Space.com brings word of a team using new evidence is suggesting that the mysterious 1908 event in Tunguska was a comet despite a team two years ago arguing it was an asteroid. The comet theory does explain the odd phenomenon of the night skies being lit up for several nights following the event all across Europe--about 3,000 miles away. Researchers believe this points to a comet because when the space shuttles launched today pass through the atmosphere they cause or improve the formation of noctilucent clouds. These clouds are so high up (55 miles) they are only made of ice particles and they are only visible at night which gives researchers reason to draw the conclusion that the 300 metric tons of water vapor that the shuttle pumps into the Earth's thermosphere must likely indicate that the thing that hit was loaded with water or ice. This would make it a comet and not an asteroid. This--of course--raises new upper-atmosphere physics problems for the Tunguska event but explains the strange phenomenon over the skies of the world following it. You may remember analysis of Lake Cheko last year in an effort to better understand what happened.
Well, if every comet that hit earth dropped off a little bit of water--even in the form of noctilucent clouds ... it'd take a while but is it really so far fetch to think that ultimately all our water and atmosphere are extra-terrestrial? Probably unlikely but over a long enough time, who knows?
My work here is dung.
Nitrogen came from comets, and methane came from Uranus.
... how could anyone reasonably think that comets brought it all?
"I don't know, therefore Aliens" Wafflebox1
The article notes that the ratio of the nitrogen isotopes matches what is in the earths atmosphere. It seems to me, that just makes it possible that the comets are a significant source of the nitrogen on Earth. It is also possible that the nitrogen in the comets and in the atmosphere came from a common source.
Duh, it reproduced once it arrived on Earh.
In addition to creating an atmosphere on earth, comets may also have seeded life.
Comets Probably Seeded Earth's Nitrogen Atmosphere
So we've been breathing space spooge all along?
Well THAT explains a lot...
[End Of Line]
Everyone knows nitrogen is here because of the Holy Sauce dripped from His Noodly Appendage.
Although comets may have initiated seeding of life and the foundry of everything from water to minerals .. there has been proof that water is abundant in space and maybe have just been absorbed into the atmosphere on earth and generated that way, over time rain would have brought the water molecules to the surface.
http://www.space.com/scienceastronomy/astronomy/milkyway_water_010412.html
It's not a typo if you understood the meaning!
Astronomers renamed that planet in 2020 to stop that stupid joke once and for all.
Oh. What's it called now?
Urectum
Conscience is the inner voice which warns us that someone may be looking.
My guess is that earth started out as a (not -so-giant?) gas giant and bled of most of it's original hydrogen. If that's even vaguely true, then there's little likelihood that the isotope mix would be anywhere near what's in comets.
I'm guessing that the deuterium mix is much higher than in comets (because deuterium, being heavier than hydrogen, is less likely to bleed off).
Free Software: Like love, it grows best when given away.
just about anything in the universe, and specifically various aspects of this planet, is becoming more like numerology than anything else. Case in point:
But on the other, they say that the ratio of nitrogen isotopes in these comets almost exactly matches the ratio in Earth's atmosphere. That suggests that while Earth's oceans must have come from somewhere else, Earth's early atmosphere was probably seeded by comet.
Any pattern they find seems to make scientists believe something is true, no matter how improbable. Scientists are only seeing what they want to see in this data. Despite this method of guessing based on simply "interesting patterns" and hoping they are right, these very same people consider taking on faith what the Holy Bible says about the origins of the world as being ludicrous. Ahhh, nothing like the smell of hypocrisy in the early morning hours. Flame on for bucking the *insertGroupNamehere* agenda.
this nation, under God, shall have a new birth of freedom. -- Lincoln, Gettysburg Address
If everything is made of electrons, protons, neutrons,.... then any thing can form from anything ;-)
The theory of comets as a source of water was also published in 1990, by Louis A. Frank.
Not exactly your average crack-pot scientists, Frank was the designer of something like 13 payloads on various launch vehicles in the 80s and 90s.
Frank posits that that small comets still hit the moon and earth almost daily, delivering water virtually every day. These small comets are more like fluffy snowballs, and are small enough not to have much if any radar signature, but their effects upon impact with the atmosphere are visible from above.
http://en.wikipedia.org/wiki/The_Big_Splash_(book)
Excerpt from The Big Splash
by Louis A. Frank with Patrick Huyghe
Published by Birch Lane Press, 1990.
ISBN 1-55972-033-6
http://smallcomets.physics.uiowa.edu/blackspot.html
Sig Battery depleted. Reverting to safe mode.
"One of the biggest puzzles of astrobiology is the origin of the Earth's oceans and atmosphere." No, it isn't a mystery.... Gen 1:1 In the beginning God created the heaven and the earth. Gen 1:2 And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters. Gen 1:6 And God said, Let there be a firmament in the midst of the waters, and let it divide the waters from the waters. Gen 1:7 And God made the firmament, and divided the waters which were under the firmament from the waters which were above the firmament: and it was so. Gen 1:9 And God said, Let the waters under the heaven be gathered together unto one place, and let the dry land appear: and it was so. Gen 1:10 And God called the dry land Earth; and the gathering together of the waters called he Seas: and God saw that it was good.
If those passages aren't a mystery to you then I say you need to go back to elementary school and learn how to read critically. Who is this God character? How did he create the heaven and the earth from something without form, out of a void? There are obviously some details missing and I demand a refund for this explanation of the universe you have sold to humanity.
I keep going over the proof for Noah's flood. It's not as far-flung as it sounds if you actually RTFM. It calls for a number of animals that would fit in a rowboat- it doesn't have to be millions. And it doesn't have to be a full world, either: Rome 'taxed the world' and I'm certain they didn't get New Jersey.
So here's the question.
What *actually* happens when the poles reverse and the Van Allen (etc) belts come down for a short time? The solar wind, largely H3 I'm told, touches an oxygen-covered surface at 33,000mph. So hot hydrogen..on oxygen...rain?
Everyone I've asked just asserts how ridiculous the question is, but no one ever has a response, other than to roll their eyes. There must be an answer- another reversal is coming up.
And this relates to the article by suggesting the pathology that the planet was heavy *nitrogen* first, and the added water brought the oxygen...
I'm not a scientist, but obviously neither are the people I've asked.
--- For a good time mail uce@ftc.gov
You might theoretically make anything into anything but from a practical standpoint it is difficult. Show me how to turn wood into gold and I'll buy it ;-) (pun intended)
I was under the impression that the Earth's water precipitated out of the original accretion disc as the early earth cooled. That is, everything accreted, and then as the molten rock and surrounding gases cooled to form a sold surface, the water that became the Earth's oceans and such also cooled and condensed, and basically rained down on the planet over time.
Has there been some reason to doubt this? i.e. evidence that refutes this hypothesis?
"Empathise with stupidity, and you're halfway to thinking like an idiot." - Iain M. Banks
DUH, scientists have found significant evidence that we're all leftovers from old stars and supernovas. Its no surprise that everything in our vicinity would be very similar to each other, since we all came from the same place.
It's easy (unless you're a fundie) to understand where the heavier elements and such come from, since they melt at high temperatures.
But water and the "stuff" that are gases at STP are volatile. So... what kept them "near" the earth while it was very hot (way past the boiling point of waster) and small and accreting? There wasn't enough of a magnetosphere to protect any atmosphere.
Could it be that H2O, N2 and O2 were created from the decomposition of very hot rocks?
"I don't know, therefore Aliens" Wafflebox1
In the beginning God created the heavens and the earth. Now the earth was formless and empty, darkness was over the surface of the deep, and the Spirit of God was hovering over the waters. And God said, "Let there be light," and there was light. God saw that the light was good, and He separated the light from the darkness. God called the light "day," and the darkness he called "night." And there was evening, and there was morningâ"the first day.
And God said, "Let there be an expanse between the waters to separate water from water." So God made the expanse and separated the water under the expanse from the water above it. And it was so. God called the expanse "sky." And there was evening, and there was morningâ"the second day.
And God said, "Let the water under the sky be gathered to one place, and let dry ground appear." And it was so. God called the dry ground "land," and the gathered waters he called "seas." And God saw that it was good.
Then God said, "Let the land produce vegetation: seed-bearing plants and trees on the land that bear fruit with seed in it, according to their various kinds." And it was so. The land produced vegetation: plants bearing seed according to their kinds and trees bearing fruit with seed in it according to their kinds. And God saw that it was good. And there was evening, and there was morningâ"the third day.
And God said, "Let there be lights in the expanse of the sky to separate the day from the night, and let them serve as signs to mark seasons and days and years, and let them be lights in the expanse of the sky to give light on the earth." And it was so. God made two great lightsâ"the greater light to govern the day and the lesser light to govern the night. He also made the stars. God set them in the expanse of the sky to give light on the earth, 18 to govern the day and the night, and to separate light from darkness. And God saw that it was good. And there was evening, and there was morningâ"the fourth day.
And God said, "Let the water teem with living creatures, and let birds fly above the earth across the expanse of the sky." So God created the great creatures of the sea and every living and moving thing with which the water teems, according to their kinds, and every winged bird according to its kind. And God saw that it was good. God blessed them and said, "Be fruitful and increase in number and fill the water in the seas, and let the birds increase on the earth." And there was evening, and there was morningâ"the fifth day.
And God said, "Let the land produce living creatures according to their kinds: livestock, creatures that move along the ground, and wild animals, each according to its kind." And it was so. God made the wild animals according to their kinds, the livestock according to their kinds, and all the creatures that move along the ground according to their kinds. And God saw that it was good.
Then God said, "Let us make man in our image, in our likeness, and let them rule over the fish of the sea and the birds of the air, over the livestock, over all the earth, and over all the creatures that move along the ground."
So God created man in his own image,
in the image of God he created him;
male and female he created them.
God blessed them and said to them, "Be fruitful and increase in number; fill the earth and subdue it. Rule over the fish of the sea and the birds of the air and over every living creature that moves on the ground."
Then God said, "I give you every seed-bearing plant on the face of the whole earth and every tree that has fruit with seed in it. They will be yours for food. And to all the beasts of the earth and all the birds of the air and all the creatures that move on the groundâ"everything that has the breath of life in itâ"I give every green plant for food." And it was so.
God saw all that he had made, and it was very good. And there was evening, and there was morningâ"the sixth day.
Genesis 1
I can easily picture the Flying Spaghetti Monster lobbing comets around ...
This is a rapidly evolving field and I don't pretend to have more than a very casual reader's knowledge - but think of it like this. The Earth is, in cosmic terms, a small planet. Its water layer is a minute fraction of its mass. In terms of the solar system as a whole, the percentage of the available water on Earth is extremely small.
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."
I am tired of hearing that water or atmosphere have come from comets.
What are comets? Aren't they the remnants of what did not become planets? Don't they come from the same cloud of dust that formed the solar system?
So, what the hell is this theory that water or atmosphere or life comes from outside earth? From comets?
The process of formation of earth included comet and asteroid collisions. It's the way planets are formed. The whole planet formed from matter from outside of earth because planets are formed by matter as it begins to group by the effect of gravity.
what happened to the dept tag?
Media that can be recorded and distributed can be recorded and distributed.
-kfg
No. Next question please.
I find these stories kind of unfulfilling. No matter how far we get back in nature's cause and effect, I'm still left thinking 'what came before that'. When scientists finally discover the root of all creation, I'll still be thinking the same thing.
"In the absence of the ability to establish the attribute of truth they tried to establish the noble attributes."
Ever think that the ones we measure now don't have a lot of water because all the ones with water already hit the planet? Not to say that its necessarily likely that ALL the comets with significant amounts of water would hit the Earth, but we've only measure what, 4 comets, I don't think that's enough to make the assumption that the water on Earth could not have come from comets.
Couldn't it just be that there was a high abundance of water or hydrogen and oxygen at least in the inner regions of the solar system that was just successively collected through gravity, when/after the earth formed ?
Of the inner planets, Mercury is simply too small and too close to the sun to hold water, Venus has almost the mass of the earth, but has a different athmosphere and is extremely hot. It's probably also just too close to the sun.
Closest outer planet is Mars, it's supposed to have had water, maybe still has some in frozen form. Mars is probably just too small, maybe also too cold to build a similar athmosphere.
So I wonder, if water molecules or hydrogen and oxygen maybe just haven been there in high abundance around the sun, but the earth was the most successful collector after all that's also able to holds a lot of it's water (not dissipating it back in space and not having a lot of chemical reactions on that use those molecules up again). The reason, why earth did it so well might just be that it has the right mass and is in the right distance to the sun to have the right temperature.
Maybe the ratio of normal hydrogen to deuterium was also dependent on the distance to the sun. So actually only the matter that clustered together through gravity around earth orbit has the ratio that we meassure on earth. The commets that were tested might have formed somewhere else.
I wonder, if the water on the Jupiter and Saturn moons shows a different ratio of deuterium and hydrogen. That might support that idea.
# Second day: God creates a firmament ("Let a firmament be...!") - the second command - to divide the waters above from the waters below. The firmament is named "heavens". # Third day: God commands the waters below to be gathered together in one place, and dry land to appear (the third command). "Earth" and "sea" are named. God commands the earth to bring forth grass, plants, and fruit-bearing trees (the fourth command). Borrowed From http://en.wikipedia.org/wiki/Creation_according_to_Genesis
"Be wary of the man who urges an action in which he himself incurs no risk."
~Joaquin Setanti
to believe in some of these theories....
Thanks to file sharing, I purchase more CDs
Thanks to the RIAA, I buy them used...
This is a comparison, not a correlation.
No kidding!!! What do you say at this point?
Why isn't Venus's atmosphere mainly nitrogen then? I don't think comets selectively crashed into earth so they could build it an atmosphere.
Most of the nitrogen in the Earth's atmosphere is N-14, which is the natural decay product of Carbon-14. Likewise, most of the argon in the atmosphere is Ar-40, which is the natural decay product of Potassium-40. Therefore I'd say the comet comparison is just a coincidence.
You damned near killed em!
they say that the ratio of nitrogen isotopes in these comets almost exactly matches the ratio in Earth's atmosphere. That suggests that while Earth's oceans must have come from somewhere else, Earth's early atmosphere was probably seeded by comets.
Or the nitrogen in the comets and the nitrogen in the Earth's atmosphere had a common origin which seems much more likely, the story title notwithstanding.
This is only a puzzle if you come from a particular worldview.
By the time that you've got your rocks molten, their water, CO2 and ammonia (nitrogen in it's most-likely protoplanetary form) would have pretty-much fucked right off. At the time that the Moon was formed (giant impact hypothesis, still the best one running), much of the depth of the mantle was temporarily ejected into low proto-Earth orbit, and at sufficient temperatures that significant amounts of such volatile ions as sodium were also lost from the material that accreted into orbit to form the Moon. This can be quite clearly seen in the composition of lunar rock samples - noticeably sodium deficient and as dry as a bone.
In planetary science, it is uncontroversial that no-matter how wet the Earth was when it formed, it was fairly well dried out by the time the Moon had formed. Consequently, the Earth then had to acquire it's volatile load (water, nitrogen-as-ammonia, carbon dioxide) after the Giant Impact. Since the Giant Impact would have necessarily (?? well, most likely) involved the mutual accretion of the two largest bodies remaining in the Earth's orbital range form the Sun, there wouldn't have been much left to accrete after that. So, most of the Earth's volatiles must have come form somewhere else.
That's one line of "geologically-based" thinking that leads to the Earth's non-volatile and volatile components having different origins. There's a simpler, astrophysically-based line of thinking that leads to the same conclusion from different premises : many meteorites contain a class of devitrified formerly-glassy chondrules called CAIs (Calcium-Aluminium[-rich] Inclusions) which give some of the oldest ages in the solar system (from our inventory of samples, but these are well and diversely sampled from stony meteorites, and give a coherent thermal history) ; the de-vitrified glassy textures tell that they were metamorphosed from a glass at temperatures consonant with their surrounding mineralogies in their various meteorites, and the fact that they were previously glasses tells us that they had got hot enough to melt and then cooled fast enough to become glassy. That tells us something about the thermal history of the early times of the solar proto-planetary disc. Which in turn tells us something about the early heating history of the sun. Which ties in with our understanding of nuclear fusion, which is good enough to make bombs if not power plants. And the whole lot boils down to (pun not intended) ... in the early accretion of the Earth, and most meteorites, anywhere much Sunwards of the asteroid belt was too hot for water-ice (let alone ammonia-ice or carbon-dioxide-ice) to be stable.
The early Earth (and Mercury, Venus and to a lesser degree Mars) was pretty dry when it accreted. All got significant amounts of their volatile inventory later in the formation of the Solar System, after the "rocky" planets had essentially completed forming.
I am not aware (IANA Planetary Scientist, but I am a geologist by trade, currently steering a horizontal oil well) if the accumulation of water ice evaporated from the "rocky planets" region onto the proto-Jupiter is currently "fingered" as what tipped that one into becoming big enough to start to accrete hydrogen directly. But I am pretty sure that it has been suggested. The modelling is, as I think I've hinted, complex.
But the PS story is clear : the terrestrial planets got most of their volatiles AFTER they had effectively finished accreting.
Hmm, have we got the well sidetracked yet? Oh dear. Oh very dear.
Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"