Extraterrestrial nucleobases in the Murchison meteorite

TL;DR

This study provides isotope evidence that nucleobases in the Murchison meteorite are extraterrestrial in origin, suggesting such organic molecules existed in the early solar system and could have contributed to the origin of life.

Contribution

It presents compound-specific carbon isotope data confirming the indigenous, non-terrestrial origin of nucleobases in a meteorite, indicating prebiotic organic molecules were present in the early solar system.

Findings

Uracil and xanthine have non-terrestrial carbon isotope ratios.

Organic nucleobases are indigenous to the meteorite.

Implication of extraterrestrial organic molecules in life's origins.

Abstract

Carbon-rich meteorites, carbonaceous chondrites, contain many biologically relevant organic molecules and delivered prebiotic material to the young Earth. We present compound-specific carbon isotope data indicating that measured purine and pyrimidine compounds are indigenous components of the Murchison meteorite. Carbon isotope ratios for uracil and xanthine of delta13C=+44.5per mil and +37.7per mil, respectively, indicate a non-terrestrial origin for these compounds. These new results demonstrate that organic compounds, which are components of the genetic code in modern biochemistry, were already present in the early solar system and may have played a key role in life's origin.