Agglomeration of 67P/Churyumov-Gerasimenko from clathrates and crystalline ices
Abstract
The origin of cometary volatiles remains a major open question in planetary science. Comets may have either agglomerated from crystalline ices condensed in the protosolar nebula (PSN) or from amorphous ice originating from the molecular cloud and interstellar medium. Here, based on the recent argon, krypton and xenon measurements performed by the ROSINA instrument aboard the European Space Agency's Rosetta spacecraft in the coma of 67P/Churyumov-Gerasimenko (67P/C-G), we show that these noble gas relative abundances can be explained if the comet's building blocks formed from a mixture of gas and H2O grains resulting from the annealing of pristine amorphous ice (i.e., originating from the presolar cloud) in the PSN.
- Publication:
-
European Planetary Science Congress
- Pub Date:
- September 2018
- Bibcode:
- 2018EPSC...12..162M