Determining the origin of nucleobases such as pyrimidine and purine in meteorites is challenging due to their low abundances relative to other organics and terrestrial contamination. Because of this, an extraterrestrial origin for nucleobases in meteorites has never been unequivocally established.
Michael Callahan and colleagues, National Aeronautics and Space Administration (NASA), Maryland, USA, used liquid chromatography–mass spectrometry to investigate the abundance and distribution of nucleobases and their analogs in 12 different meteorite samples. They found that the Murchison and Lonewolf Nunataks 94102 meteorites contained the unusual and terrestrially rare analogs purine, 2,6-diaminopurine, and 6,8-diaminopurine. These compounds were not detected in the control samples which strongly suggest they are indigenous to the meteorites.
Thus, meteorites may have served as a molecular kit providing essential ingredients for the origin of life on Earth and possibly elsewhere.
Image: © U.S. Geological Survey
- Carbonaceous meteorites contain a wide range of extraterrestrial nucleobases
M. P. Callahan, K. E. Smith, H. J. Cleaves, J. Ruzicka, J. C. Stern, D. P. Glavin, C. H. House, J. P. Dworkin,
Proc. Natl. Acad. Sci. 2011.