Is Earth's Atmosphere an Import?

garg0yle writes "One of the questions about the formation of our planet is: where did the atmosphere come from? One theory is that the oxygen, nitrogen, and other gases were part of the coalescing ball, and 'seeped out' during the final stages of the planet's formation. However, a new article at Wired says isotopic analysis of krypton and xenon indicates that they (and the rest of our atmosphere) may be of extraterrestrial origin, either arriving via comets or being swept up from gas clouds."

Comments

The aliens that delivered it forgot to

[Tablizer]

...remove the flying saucers.