Does the Earth Owe its Atmosphere to Ancient Comets?

Does the Earth Owe its Atmosphere to Ancient Comets?
by beconrad

The fortuitous combination of atmospheric gases that may life as we know it possible may have a decidedly extraterrestrial origin, stemming not from the actions of terrestrial volcanoes but from the appearance of comets.

Scientists have long been puzzled by the mixture of gases in the Earth’s atmosphere ”“ and by the origins of those gases. For years one of the most popular theories has been that the gases in the Earth’s atmosphere are the result of the eruption of volcanoes. As those gases bubbled up from those ancient volcanoes, the theory goes, they helped to create the atmosphere as we know it today.

But recently researchers at the University of Manchester in the UK came up with a different theory for the origins of the Earthly atmosphere, based on their findings after they collected samples of krypton gas hundreds of meters below New Mexico.

Researcher Greg Holland and his colleagues at the University of Manchester found that the area they studied was rich in heavier isotopes of krypton but poorer in lighter versions of the gas. In fact the composition of the samples closely resembled that found in meteorites, lending further credence to an exterritorial origin of the terrestrial atmosphere.

The comet theory supposes that the current atmosphere of the Earth has its origins not in volcanoes that spewed krypton and other gases into the air but in the bombardment of the earth by thousands icy comets. Specifically this emerging research is focused on the Kupier Belt, which formed when the solar system was born. The millions of icy bodies in the Kupier belt have been found to contain a noble gas signature very similar to that of the Earth’s present atmosphere.

Scientists already know that a shift in the orbit of gas giant Jupiter took place some 4.5 billion years ago, and that shift may have been enough to move the Kupier belt and release those comets on a collision course with Earth. It is an interesting theory, and one that is bound to gain additional attention as new evidence is discovered.