Kinetic inhibition of CO and N2 reduction in circumplanetary nebulae - Implications for satellite composition

In contrast to the solar nebula, the conversion of CO to CH4 and of N2 to NH3 in the circumplanetary nebulae of the Jovian planets is fast enough relative to radial mixing and nebula cooling rates that CO and N2 are minor constituents in the circumplanetary nebulae. Thus, although the Jovian planets may have accreted carbon and nitrogen from the solar nebula mainly in the form of CO and N2, these species were then reprocessed within the circumplanetary nebulae to form mainly CH4 and NH3. Satellites of the Jovian planets which accreted in sufficiently cool parts of their circumplanetary nebula are therefore predicted to retain large amounts of NH3 and CH4 in the form of clathrate hydrates and also very small but chemically important amounts of HCN.