From Garry Marley, Stillwater, Oklahoma, US
It is not surprising that the asteroid Ryugu, among others, possesses the nucleobases that are core components of nucleic acids. I am reminded that the Murchison meteorite, impacting Australia in 1969, was replete with organic compounds, including a cache of amino acids and some nucleobases also found in terrestrial life (28 March, p 15).
Did such abiotic nitrogenous bases and amino acids seed the early warm, incubating Earth as a prelude to their syntheses into nucleic acids and proteins? These observations complement the 1952 experiments of Urey and Miller that used electrical sparks (as simulated lightning) to form a mixture of amino acids from reduced gases associated with the primordial Earth. Life and the greater cosmos surely are less separable than ever.
