Hubble Space Telescope View of Comet C/Siding Spring during its Close Encounter with Mars

Thursday, 18 December 2014: 10:20 AM
Jian-Yang Li1, Nalin H Samarasinha1, Michael S.P. Kelley2, Tony L. Farnham2, Dennis Bodewits2, Michael F A'Hearn3, Carey Michael Lisse4, W. A. Delamere5 and Max J. Mutchler6, (1)Planetary Science Institute Tucson, Tucson, AZ, United States, (2)University of Maryland College Park, Astronomy, College Park, MD, United States, (3)University of Maryland College Park, College Park, MD, United States, (4)Applied Physics Laboratory Johns Hopkins, Laurel, MD, United States, (5)Delamere Support Services, Boulder, CO, United States, (6)Space Telescope Science Institute, Baltimore, MD, United States
Comet C/2013 A1 (Siding Spring) is a dynamically new comet whose physical and chemical status should be the least evolved since the formation of cometesimals during the planetary system formation processes. Its close encounter with Mars on October 19, 2014 at a distance of 131,000 km allows for imaging its nucleus and inner coma by MRO/HiRISE at 140 m/pix resolution. Such an encounter offers us the opportunity to do cometary flyby science for a dynamically new comet for the first time ever. Those observations have the potential to advance our understanding of comets in ways similar to previous flyby missions to periodic comets. An extensive observing campaign from many ground- and space-based platforms is supporting the “flyby” observations from Mars spacecraft. We will monitor the comet with Hubble Space Telescope for >24 hrs total observing time around the encounter, to obtain images of the inner coma at ~46 km/pix at the comet. These observations will allow us to perform detailed studies of the morphology of the dust and gas coma of C/Siding Spring, and to connect the observations performed from various platforms at various spatial resolutions and over a long time baseline. The ultimate goal is to correlate large-scale coma behaviors to the nucleus as resolved by MRO/HiRISE. We will report the HST observations and the preliminary results.