Presentation #411.02 in the session Cometary Volatiles (iPosters).
Comet 103P/Hartley 2 is a hyperactive comet that has relatively high production rates of H2O and CO2 gases. The comet was visited by the Deep Impact spacecraft during the extended EPOXI mission on Nov 4, 2010. The closest approach distance to the comet was 694 km when the comet was about 1.06 AU from the sun. Images and spectra were taken by the MRI and HRI onboard. The infrared measurements of the innermost coma acquired close to the comet revealed the H2O vapor was mostly released from the waist of the nucleus, and CO2 and ice chunks/grains were emitted from the small end of the bi-lobe shaped nucleus. Besides being monitored by spacecraft, the coma was also measured by SOHO/SWAN and ground-based telescopes during the apparition. Interesting discrepancies existed in the H2O production rate measurements. The measurements with larger apertures have larger production rates, which leads to the explanation that a significant amount of H2O in the coma is produced by the extended sources or icy grains or chunks. In this work, we feed the HRI images, which were taken within 1 hour before and after the closest approach, into our inversion model to determine the potential H2O and CO2 source regions on the surface of the comet. The resulting potential source regions combined with the observation specific solar illumination conditions will yield the total H2O and CO2 gas fluxes from the surface. The production rates from the nucleus will be compared with other measurements. Support for this work comes from grant 80NSSC17K0212 from the NASA Discovery Data Analysis Program.