THE GLOBAL HIGH RESOLUTION SHAPE MODEL OF THE NUCLEUS OF 67P

The new “67P-133M” three-dimensional shape model of the nucleus of comet 67P/Churyumov–Gerasimenko makes use of all images taken after perihelion from 2015 October 26 to 2016 February 10, that is 7,682 NAC and 1,504 WAC images. It was constructed using the “Agisoft Metashape” advanced, stand-alone software which performs photogrammetric processing of digital images and generates 3D spatial data (https://www.agisoft.com). The resulting high resolution 3D model of the whole nucleus has 133 million facets (66 million vertices) to be compared with about 44 million facets for the SHAP7 model of Preusker et al. (Astronomy & Astrophysics, 607, L1, 2017) which has been used as a reference until now.

Figure 1 illustrates the dramatic difference between the two models in the case of a deep cavity as it is literally smoothed out in the SHAP7 model.

Figure 1. Comparison of the SHAP7 model of Preusker et al. (2017) (left column) with the “67P-133M” model in the case of a deep cavity. This cavity has a size of 18.4 × 16.2 m and a depth of 47 m (Lamy et al., Monthly Notices of the Royal Astronomical Society, 531, 2494, 2024). Two representations are displayed, solid model (upper row) and wire-frame model (lower row).

Figure 2 presents an anaglyph of a region constructed from the 67P-133M model.

Figure 2 Anaglyph of a region of the big lobe of the nucleus constructed from the 67P-133M model. A texture derived from the images themselves was applied to the shape model for a realistic rendering of the nucleus surface. See Lamy et al., Monthly Notices of the Royal Astronomical Society, 531, 2494, 2024 for further detail.