Kinetic inhibition of CO and N2 reduction in the solar nebula

Abstract

It is shown that the conversion of CO to methane and of N 2 to ammonia in the primitive solar nebula was probably so slow relative to radial mixing rates or nebula evolutionary rates that only small amounts of NH 3 and CH 4 could have been present. Thus most of the nitrogen was present as N 2 and most of the carbon as CO and C0 2 throughout the nebula. The consequences of this kinetic effect upon the composition of cometary ices and of the Jovian planets, the melting and outgassing behavior of ice-rich planetary satellites, and the abundance of carbon in the terrestrial planets are briefly discussed.