Analyses of noble gases hint that air didn't fizz from within the planet
Isotopic analyses of the gases krypton and xenon suggest that much of Earth's atmosphere came from outer space, not inner space.
Krypton and xenon appear in Earth's atmosphere - and in the universe as a whole - only in trace amounts. Detailed analyses of the gases provide clues about where those atmospheric components originated, says Greg Holland, an isotope geochemist at the University of Manchester in England. Those analyses, reported in the Dec. 11 Science, suggest that those gases, as well as many others now cloaking our planet, arrived via comets or were swept up from nearby gas clouds during the late stages of Earth's formation.
Some scientists have proposed that the gases in Earth's atmosphere originated within the planet, says Holland. According to those arguments, the atmosphere either seeped out of the Earth as the planet gradually cooled or were expelled from the crust when large numbers of asteroids pummeled the planet and melted its surface around 3.9 billion years ago. But new isotopic evidence gathered by Holland and his colleagues suggests that those scenarios probably aren't right.
The researchers analyzed samples of gas pulled from a natural reservoir of carbon dioxide that lies several hundred meters below northeastern New Mexico. There, Holland explains, krypton and xenon that originate deep within the Earth - gases that presumably accumulated when the planet coalesced billions of years ago - mix with small amounts of atmospheric krypton and xenon carried downward by rainfall and groundwater.
Ratios of isotopes of krypton and xenon present in the geologic reservoir don't match the ratios seen in today's atmosphere. In particular, heavier isotopes of each gas appear in larger proportions in the subterranean samples than they do in the atmosphere. So it's unlikely that large amounts of these atmospheric gases came from within the Earth, the team argues.
Analyses also show that if the geologic gas samples weren't tainted by atmospheric krypton and xenon, the isotope ratios measured for those gases would match the ratios seen in meteorites. That's another sign that neither the planet nor meteorites were the source of the isotopically light xenon and krypton in today's atmosphere, Holland notes.
Instead, he and his colleagues propose, the krypton and xenon now present in the air - and many other atmospheric components as well - may be remnants of gas clouds swept up by the newly forming Earth. Or, they suggest, the gases may have been delivered to Earth by comets, in which the proportions of light isotopes for xenon and krypton are relatively higher.
"This is an important piece of work, and an extremely interesting contribution to studies of how the atmosphere evolved," says Robert Pepin, an astrophysicist at the University of Minnesota in Minneapolis. But the team's results aren't unambiguous, he notes. The krypton and xenon in today's atmosphere may, for example, be a mix of isotopically light gases delivered by comets and the heavier versions originating within the Earth.
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I don't remember which nucleids are creating each isotope of krypton and xenon, but I guess there are several ways to make them. I find anomalies like this very promising, because we need to find better ways to account for most Cosmological phenomena.
Each abherrant obseravion is (in my view) undermining old theories, that don't hold water (as explanation models, I mean)...
But, the fact that lighter isotopes are found higher up than the heavier ones, seems logical, although, with such heavy gasses the weight difference, between isotopes, should be less signifigant, than with lighter ones. But, there may be contributions that are more recent, than suggested, and the Age of the Earth, planets, Suns and Universes, is in my opinion, anybodys guess...
I think we cannot rule out contributions from the inner solar system, especially the sun itself, solar win, and outbursts, maybe... Who knows?, but also Venus, -and by the way, what happened to the atmosfere of Mars? Isn't recent observations on Mars, indicating that it in a relatively 'close' past, maybe just a few thousand years or a few millions, had a much denser atmosfere, that was supporting life (maybe like the organisms we find on Earth?), and a surface with liquid water.
Why is it now such a thin atmosfere there, with just a little nitrogen and CO2 ?
Ofcourse, we can't rule out comets and other impacts, or near fly by's -
And, how shure can we be that the planets have been where they are today, since the Sun was developed, and is it really a fusion reactor hanging in the sky ?
Todays models of the development of the solar systems, the planets, the galaxies - and ultimately the Universe itself, creates more questions than they answer.
"Modern" Physics and Cosmology, have created models that I find totally unconvincing, for all I've studied. To me, people like Einstin and Bohr, and their ilk, are venereted to much. Einstein was most of all a genius ihn promoting himself. The Hubble constant and the Big Bang, are utterly nonsensical ideas, when observing, what really goes on, out there...
I think it all could become much simpler, if we trashed all preconceptions, and started without the idea that everything should fit mathematical equations, and started to look at what is going on without, being bound up by all preconceptions, since Newton explained the planetary orbits we see today. I find all these deviating observations, in later years utterly promising. I like bold new ideas like those of Halton Arp, and others, who tells things that should be obvoius, like the fact that electro-magnetism is just as important as gravitation in explaining how the solar system, or the Univers functions. And how could they scrap the 'aether'-concept, in such an off-hand, way, -just because it didn't fit Einsdteins equations??
If we accounted for the consequences of great charge separations, we wouldn't need concepts like "dark matter/energy", neutron stars, or Black holes !!!
Why should the speed of light be a limiting factor ?
Regarding timing:
I doubt most techniques used for assessing events more than about 1000 years back in time.
(When it comes to "History", I'm a skeptic of it all, - although I believe the timeframes for the last 500 years to be pretty good)...
When it comes to things happening millions, or even 100s or 1000s of millions of todays cycles around the sun, (about 365 and about 1/4 days - or times the Earth rotate about its own axis, in each cycle around the sun). How long this system has been pretty stabile, I reckon we can guess, is more than 4000 'years', -but all measurements by isotopes, or relative concentrations of various nucleids, I find many reasons to doubt, the paradigms that are used to support the hyporheses, including my own, but this is just to make it clear that I'm too, hypothezising on very shaky fundaments...