MOLECULAR OXYGEN IN OORT CLOUD COMET 1P/HALLEY

Recently, the ROSINA mass spectrometer suite on board the European Space Agency's Rosetta spacecraft discovered an abundant amount of molecular oxygen, O-2, in the coma of Jupiter family comet 67P/Churyumov-Gerasimenko of O-2/H2O = 3.80 +/- 0.85%. It could be shown that O-2 is indeed a parent species and that the derived abundances point to a primordial origin. Crucial questions are whether the O-2 abundance is peculiar to comet 67P/Churyumov-Gerasimenko or Jupiter family comets in general, and also whether Oort cloud comets such as comet 1P/Halley contain similar amounts of molecular oxygen. We investigated mass spectra obtained by the Neutral Mass Spectrometer instrument during the flyby by the European Space Agency's Giotto probe of comet 1P/Halley. Our investigation indicates that a production rate of O-2 of 3.7 +/- 1.7% with respect to water is indeed compatible with the obtained Halley data and therefore that O-2 might be a rather common and abundant parent species.