Using Deep Impact to Continuously Monitor Spatial Variations in 103P/Hartley 2's Volatiles
Abstract
The Deep Impact spacecraft flew by the hyperactive comet 103P/Hartley 2 on November 4th, 2010 during its extended mission. Spectral maps of the innermost coma were created using infrared spectroscopy data from the High Resolution Instrument (HRI-IR; 1-5 μm) onboard. The dominant detected volatile species, water (2.7 μm) and carbon dioxide (4.3 μm), were found to have different spatial distributions near closest approach, suggesting the source of the volatiles are distinct (A'Hearn et al., Science, 2011). Expanding on previous closest approach studies (Sunshine et al., DPS, 2013 and Feaga et al., ACM, 2014), spatial and temporal variations of water and carbon dioxide in the coma are examined throughout the 23 days of continuous observations around closest approach from scans collected every 15 minutes to every hour. Both of the volatiles vary over a primary rotational period of 18 hours and the complex rotational period of 55 hours (Belton et al., Icarus, 2013) resulting in triple-peaked light curves. However, the water and carbon dioxide light curves differ. The spatial distributions of the volatiles are used to interpret the light curves and better constrain Hartley 2's rotation. Correlations of varying volatile activity with respect to sources on the nucleus and in the coma with the shape and features of the nucleus, rotation, and illumination are also investigated. This unique data set provides continuous monitoring of Hartley 2 over very short timescales for an extended period of time. Previous observations of other comets are snapshots acquired less frequently and thus cannot resolve rotational variations as seen here. Therefore, the Deep Impact Hartley 2 data have implications for the interpretation of such observations.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.P23G3523H
- Keywords:
-
- 6008 Composition;
- PLANETARY SCIENCES: COMETS AND SMALL BODIESDE: 6017 Erosion and weathering;
- PLANETARY SCIENCES: COMETS AND SMALL BODIESDE: 6023 Comets: dust tails and trails;
- PLANETARY SCIENCES: COMETS AND SMALL BODIESDE: 6025 Interactions with solar wind plasma and fields;
- PLANETARY SCIENCES: COMETS AND SMALL BODIES