Alteration of interstellar organic materials in meteorites' parent bodies

Based on experiments that model interstellar organic materials, we found that both C and N contents and IR spectra of insoluble organic materials in carbonaceous chondrites could be reproduced well by the aqueous alteration and the subsequent thermal metamorphism. The resulting sample shows strong evidence of diamond, which indicates that this process is an unexpeccted mechanism that might produce extensive amount of diamond in meteorites' parent bodies. Because this process requires neither high pressures nor energetic processes, the present results suggest an alternate origin of diamonds in meteorites.