A group of geochemists think they have discovered the origin of the Xenon, the noble gas present in our atmosphere, and it is not from here! This enigmatic gas has intrigued scientists over decades for various reasons, including how it came here, and why it has apparently disappeared.
According to new data from the Rosetta spacecraft, about a quarter of the Xenon present in our atmosphere probably originated from comets, and in addition to helping to dissolve the intricate dilemma that has plagued scientists forever, this new discovery also helps scientists to better understand how potentially comets were also responsible for the existence of other matter present on our planet, such as water.
“The isotopic composition of xenon is similar to that of a primordial atmospheric component,” said geochemist Bernard Marty of the University of Lorraine in France and added, “the Earth’s current atmosphere contains about 22 percent xenon from comets”.
Xenon, like other noble gases such as helium and argon, is a gas with no odor, color, and practically no reaction, although some of its compounds may be highly explosive.
Although xenon is extremely rare, about a 20 million part in the atmosphere, in our day to day there are several commodities that make use of this, such as car headlights, projectors and even plasma screens.
Xenon is also the densest noble gas known to us, being 4 times denser than air and containing 9 stable isotopes, but the most intriguing fact about xenon is that it does not behave as it was supposed to, when compared to other common noble gases. To begin with, about 90 percent of the xenon gas that should be in the atmosphere is not actually there, and there are several theories to where the missing gas is, including in the Earth’s core. But the dilemma does not stop here and it thickens as scientists try to figure out from where the xenon present in out atmosphere came from, since by the current models, at least part of it, must have come from an unknown source that until now hadn’t been identified.
But the arrival of the Rosetta spacecraft, and the completion of part of its mission to surround the comet 67P/Churyumov-Gerasimenko in 2004, allowed after some processing of the collected data, to conclude that the comet’s gas was already there before our Solar System formation, and that the isotopic signature of the gas corresponded to the signature of the one present in our atmosphere.
More curious, the scientists discovered that the xenon gas present in the comet and in our atmosphere, differ in its isotopic signature of all xenon gas detected so far in the Solar System, proving that its origin was set before the formation of our system.
This confirms that at least part of the xenon gas originated from comets, and came from outside our solar system, and comes to increase the possibility of much of the other components arriving to our planet the same way.