Organic matter on comet 67P

The COSIMA mass spectrometer on board the ESA Rosetta spacecraft has detected more than 27,000 particles in the vicinity of comet 67P/Churyumov–Gerasimenko. Of these, more than 200 particles have been analysed so far and this paper presents further chemical analysis of two of these particles, dubbed Kenneth and Juliette. The results reveal the presence of solid organic matter, in which the carbon is bound in very large macromolecular compounds, analogous to the insoluble organic matter found in the carbonaceous chondrite meteorites. The authors conclude that the observed cometary carbonaceous solid matter could have the same origin as the meteoritic insoluble organic matter, but has suffered less modification before and/or after incorporation in the comet.