The Analysis of Comet Mass Spectrometric Data

The mass spectra from the Giotto PICCA experiment have been studied using computer simulations based on tabulated mass spectrometric data. It is shown that random mixtures of organic compounds give rise to mass spectra with peaks at ca. 45, 60, 75, 90, i.e. separated by ca 15 amu. In particular it is shown that the products of Urey-Miller type experiments give mass spectra which can match the observed Giotto data closely. The analysis indicates that the material consists mainly of C/H/O/N (i.e. it is organic) but that the assignment to any well defined organic material is less certain. It is not clear that mass spectrometric studies of complex organic mixtures have the prospect of yielding this type of information without some form of pre-separation.