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Comet 67P's abundant oxygen more of an illusion, new study suggests
- goatsneez 5y agoFor those interested the O2 detection in comets (at a level of 5-10% of gas) has been a "huge" problem, first, it is a reactive molecule, second, it can lead to explosions (under certain conditions). [That has been suggested before]. Third, O2 should diffuse out (even far away from the Sun) of the interior on the order of 10^5 to 10^7 years (depending on porosity, which is on the order of 60-70% on average. That is volume of empty space is larger than volume of matter !) The ice is also (micro)-porous on comets. Comets, however, are believed to be the age of our solar system. The study suggests that O2 is slowly diffusing out from deep interior (at constant rate), gets trapped in under-surface pockets of impenetrable material (ice+dust) and under right illumination conditions gets released as the ice sublimates. This is opposed to suggestions that O2 is produced locally from photo or ion chemistry (which was previously doubted already). Last tidbit, comet Haley data were also reanalyses and show similar O2/H2O (which is this study does not address).