Our atmosphere came from outer space

Comets from outer space may have created Earth's atmosphere – not volcanoes spewing out gases from deep within the planet.

The origin of the gases in Earth's atmosphere has long been a puzzle. One of the main theories is that the gases bubbled up out of the mantle via volcanoes.

Greg Holland of the University of Manchester, UK, and colleagues have arrived at a different theory after collecting samples of the noble gas krypton from several hundred kilometres beneath New Mexico.

Source : New Scientist

http://www.newscientist.com/article/dn18277-our-atmosphere-came-from-outer-space.html