Constraint the Coma Environment and the Ortho-to-Para Ratio of water by Rosetta VIRTIS-H Observation

Yu-Chi Cheng^1,2*, Dominique Bockelée-Morvan¹, Stéphane Earad¹, Fabrizio Capaccioni³, Cédric Leyrat¹, Gianrico Filacchione³

¹Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique (LESIA), Observatoire de Paris, Paris, France
²Department of Physics, National Taiwan Normal University, Taipei, Taiwan
³INAF-IAPS, Istituto di Astrofisica e Planetologia Spaziali, Rome, Italy

* Presenter:Yu-Chi Cheng, email:ycc312@g.ncu.edu.tw

Comet is the most ancient object in our solar system. Ice-rich cometary nuclei are believed as remnants of planetesimals forming billion years ago. The great success of the European Space Agency Rosetta rendezvous mission opened a new vision on the nature of comet 67P/Churyumov-Gerasimenko. In-situ observations from multiple instruments onboard the Rosetta spacecraft revealing unprecedented high-resolution images of the cometary surface, distribution of several chemical species in the coma environment, and other incredible scientific results we had never seen before. In this presentation, I will briefly introduce what we had learned from the Visible and InfraRed Thermal Imaging Spectrometer (VIRTIS) instrument, such as the H₂O column density measurement, constraint the physical properties of the coma environment, and estimate the Ortho-to-Para ratio (OPR) of water.

Keywords: solar system, comet, Rosetta mission