‘Meteorites helped create life on Earth’

WASHINGTON: Scientists have found components of DNA, the building blocks of life on Earth, in meteorites, a discovery they say confirms the theory that at least some of the materials needed to make early life forms came to our planet from space.

In the Nasa-funded study, published in the Proceedings of the National Academy of Sciences, scientists used advanced mass spectrometry instruments to scan 11 organic-rich meteorites called carbonaceous chondrites and one ureilite, a very rare meteorite with a different chemical composition . They found three nucleobases - purine, 6,8-diaminopurine and 2,6-diaminopurine - that are widely distributed in carbonaceous chondrites and which are "rare or absent in terrestrial biology" , said the researchers. 


The scientists found no significant concentrations of the trio in soil and ice samples near where the meteorites landed, LiveScience reported. Past research had revealed a range of building blocks of life in meteorites, such as the amino acids that make up proteins. Space rocks just like these may have been a vital source of the organic compounds that gave rise to life on Earth.

This was the first time all but two of these meteorites had been analysed for nucleobases. Study co-author Jim Cleaves said,"Finding nucleobase compounds not typically found in Earth's biochemistry strongly supports an extraterrestrial origin. This shows us meteorites may have been molecular tool kits, which provided the essential building blocks for life on Earth."