In their study, published in the journal Science and funded by Natural Environment Research Council (NERC), the team of scientists offers a new theory. Using world-leading analytical techniques they found new evidence, in the form of outer-space materials. “We found a clear meteorite signature in volcanic gases,” said Dr Greg Holland, the project’s lead scientist.
Professor Chris Ballentine of the University of Manchester, the project director, acknowledged the contradiction between the newly found evidence and contemporary theories: “Many people have seen artists’ impressions of the primordial Earth with huge volcanoes in the background spewing gas to form the atmosphere. We will now have to redraw this picture.”
The new techniques enabled the team to measure tiny quantities of the unreactive volcanic trace gases, named Krypton and Xenon. The device used is called a multicollector noble gas mass, which enables scientists to measure several isotopes at the same time (rather than one after another), thus improving the precision of the measurements. The results revealed an isotopic “fingerprint” matching that of meteorites – which is pretty much different from that of “solar” gases.
“From that we now know that the volcanic gases could not have contributed in any significant way to the Earth’s atmosphere,” infers Holland. “Therefore, the atmosphere and oceans must have come from somewhere else, possibly from a late bombardment of gas and water rich materials similar to comets.”
The new techniques were possible thanks to University of Manchester’s recently acquired devices. “Until now, no one has had instruments capable of looking for these subtle signatures in samples from inside the Earth – but now we can do exactly that,” Hollad comments.
According to the report, this study is also the first to establish the precise composition of the Krypton present in the Earth’s mantle – a measurement that might be useful for other environmental scientists.
TFOT has also covered our atmosphere’s biography, documented by National Geographic, and ozone monitoring systems, that scan Earth’s atmosphere constantly. Another related TFOT story is Modeling of Earth’s Early Interior, made by a supercomputer at the University of California, Davis.
For more information about the source of Earth’s atmosphere, see the press release posted by the University of Manchester.