Adherents to one of the more exotic (literally) theories on the origins of life has just gotten a boost of confidence, based on the latest @NASA research:
Scientists have detected the building blocks of DNA in meteorites since the 1960s, but were unsure whether they were created in space or resulted from contamination by terrestrial life. The latest research indicates certain nucleobases — the building blocks of our genetic material — reach the Earth on meteorites in greater diversity and quantity than previously thought.
The theory that life was “seeded” onto the Earth from meteorites crashing onto its surface is called Panspermia. Like the article notes, this theory has been in circulation and widely supported since the 60’s when the discovery of DNA building blocks was first made.
But the theory of Panspermia has always been hampered by the prospect of contamination: since the meteorites we observe are already on the planet, the chemicals that spark the debate might just have seeped into the rock once the meteorite was on Earth. These rocks are not, after all, recent visitors.
The current research was conducted on meteorite fragments found in the Antarctic. The scientists found that many different molecules, very similar to DNA’s base, are present in the rock. Despite the similarity, not all the chemicals found in the meteorites are commonly employed in biology.
But significantly, the ice surrounding the meteorite did not have the same chemicals present. That suggests that the meteorite in question was forming new chemicals prior to its arrival, rather than simply holding onto debris from its new home.