Meteorites ‘may have sparked life on Earth’

Tuesday, March 1, 2011

LONDON - A meteorite discovered in Antarctica could strengthen the argument that life on Earth might have been kick-started from space, claim scientists.

Chemical analysis of the meteorite shows it to be rich in the gas ammonia. It contains the element nitrogen, found in the proteins and DNA that form the basis of life, as we know it, reports the BBC.

The researchers said meteorites like this could have showered the early Earth, providing the missing ingredients for life.

The new study by researchers at Arizona State University and the University of California, Santa Cruz, is based on analysis of just under 4g of powder extracted from a meteorite called Grave Nunataks 95229, discovered in 1995.

On treatment, the powder sample was shown to contain abundant amounts of ammonia as well as hydrocarbons.

Sandra Pizzarello, who led the research, said the study “shows that there are asteroids out there that when fragmented and become meteorites, could have showered the Earth with an attractive mix of components, including a large amount of ammonia.”

Meteorites like this could have supplied the early Earth with enough nitrogen in the right form for primitive life forms to emerge, she said.

Previous studies have focused on the “Murchison” meteorite, which hit Australia in 1969, which was found to be rich in organic compounds.

The theory that our planet may have been seeded by a comet or asteroid arises partly from the belief the formative Earth might not have been able to provide the full inventory of simple molecules needed for the processes that led to primitive life.

Caroline Smith, a meteorite expert at London’s Natural History Museum agreed the important element in the new study is the nitrogen, even though she would like to see similar results repeated in other meteorites.

“One of the problems with early biology on the early Earth is you need abundant nitrogen for all these prebiological processes to happen - and of course nitrogen is in ammonia.

“A lot of the evidence shows that ammonia was not present in much abundance in the early Earth, so where did it come from?” she asked.

The findings have been published in the journal Proceedings of the National Academy of Sciences. (ANI)

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