Description of the shape model of Tempel 1, as derived from the DI and Stardust NEXT flyby data. by Peter Thomas Latitude-longitude model of 9P/Tempel 1. temple11_2012_plan.tab This data set presents the latitude, longitude, radius shape model of comet 9P/Tempel 1, as derived from the images of the comet obtained by the Deep Impact spacecraft around the time of closest approach and by the Stardust-NeXT spacecraft on February 14, 2011. Additional information about the model can be found in Thomas et al., "The Nucleus of comet 9P/Tempel 1 from two flybys" Icarus 222, 453-466, 2013. The model is presented in body-centered planetocentric coordinates, with vertices at intervals of 2 degrees in both latitude and longitude. It consists of 16022 vertices, forming 32040 plates. The radial distance is given in kilometers and ranges from a minimum of 2.10 km to a maximum 3.97 km. The shape is such that it is not well represented by a triaxial ellipsoid. Note that the center of figure is not exactly coincident with the coordinate origin. This offset has not been corrected in the present model as further refinement of the relative viewing geometry of the two missions may affect the shape model. Each row of this table contains data for one vertex, in the form of the latitude, longitude and distance from the center in a planetocentric coordinate system. The row also contains a flag denoting whether the point comes from a region well constrained by control points ("1"; these have relative errors of largely less than 60m.), or a region constrained by limb coordinates ("2", these have higher uncertainties, ~100 m, because of the ambiguity in location of the limb position), or not closely constrained ("3"; areas more than 0.4 km from either of these types of control, and may have errors of 100-300 m.). Data are from the DI and SDN missions. The DI spacecraft and its instruments are described in A'Hearn et al. (2005) and Hampton et al. (2005). Most DI data used are from the Medium Resolution Instrument (MRI) data, which had a pixel scale of 7 m at the closest approach of ~700 km, and the nearly identical Impactor Targeting Sensor (ITS), which obtained higher resolution, but smaller, windowed images just before impact. The SDN data are from the NAVCAM instrument (Brownlee et al., 2004; Newburn et al., 2003; Klaasen et al., 2011). Determination of the shape and accurate relative positioning of the images relies upon stereo control points. Limb coordinates provide additional constraints on the shape, but have an ambiguity on where the surface is intersected by the line of sight. The spin axis reported (July 2005 to Feb 2011: RA=255 deg, Dec=64.5 deg) is not an actual instantaneous vector, rather it is a rotation that makes views at the time of Deep Impact closest approach and StarDust-NeXT closest approach line up. There remain inconsistencies in the geometry from the three spacecraft (Deep Impact flyby and Impactor spacecraft, and StarDust-NeXT) that result in relative uncertainties in positions in the DI covered areas and the SDN areas of several tens of meters. The changing spin of Tempel 1 is described in Belton et al. 2011. Cartesian shape model of Tempel 1 tempel1_2012_cart.wrl A second version of the model was derived directly from the planetocentric version. In this version, the vertices are in the same locations, but are presented in cartesian coordinates. The X axis is defined in the direction of the intersection of the equator and the prime meridian, the Z axis lies along the positive pole and the Y axis completes the right-hand coordinate system. Image mosaic of Tempel 1. temple1_8ppd_imagemosaic.png Image from The MRI and ITS images on the Deep Impact mission, and the Navcam on the StarDust-NEXT mission were map projected using the derived shape model. Projection is simple cylindrical. The prime meridian has been maintained as passing through the center of a circular feature near the impact site (Thomas et al. 2007). The change of spin pole determined since 2007 means some of the latitudes and longitudes are shifted relative to previous maps. The scale is 8 pixels per degree. Images have been moderately high-pass filtered, and manually stretched to remove some of the ime-to-image differences in brightness. Images used for the maps of Tempel 1 iv0173727570_9000635_001 iv0173727666_9000647_001 iv0173727746_9000671_001 iv0173727758_9000672_001 iv0173727787_9000675_001 iv0173727818_9000680_001 mv0173728397_9001025_001 mv0173728441_9001037_001 mv0173728459_9001045_001 mv0173728468_9001049_001 mv0173728472_9001051_001 mv0173728497_9001063_001 n30035te01 n30036te01 n30037te01 n30038te01 n30039te01 n30040te01 n30041te01 Prime meridian views of Tempel 1. its_view_pm.png sdn_view_pm.png Two views of the images mosaic projected onto the shape model are provided: one from the perspective of the impactor, and one from near the closest approach of StarDust-NEXT. The prime meridian and north direction are shown. Principal direction views of Tempel 1 templeviews_gridded.png Six views of the shape model with image map overlain are shown. The viewpoints are labeled for each panel.