London: A NASA scientist claims to have discovered an alien life form -- an out of-this-world bacteria in meteorites which have fallen in remote areas across the globe.

According to Dr Richard Hoover, an astrobiologist with NASA's Marshall Space Flight Center, the alien life form could explain how life on Earth started.

He explains that while travelling to Antarctica, Siberia and Alaska he has studied an extremely rare form of meteorites -- CI1 carbonaceous chondrites -- of which only nine are known to exist on Earth.

"I interpret it as indicating that life is more broadly distributed than restricted strictly to the planet Earth. This field of study has just barely been touched -- because quite frankly, a great many scientists would say that this is impossible. The exciting thing is that they [the bacteria] are in many cases recognisable and can be associated very closely with the generic species here on Earth.”

Dr Hoover would collect each meteorite stones and break them in laboratory conditions, scanning for fossilised remains. It was then he made his discovery, identifying one biological remain as having no nitrogen -- something that, until now, is found in all living organisms.

The findings are published in the latest edition of the 'Journal of Cosmology' which have now invited scientists across the world to review Dr Hoover's claims.

Dr Seth Shostak, a senior astronomer at the SETI Institute, said there is a lot of hesitancy to believe such finding. "May be life was seeded on the Earth -- it developed on comets for example, and just landed here when these things were hitting the very early Earth.

"It would suggest life didn't really begin on the Earth, it began as the solar system was forming. The findings will need to undergo independent testing before they can be classified as a confirmed signature of life."