Macroscale Roughness Reveals the Complex History of Asteroids Didymos and Dimorphos

• DOI: 10.3847/psj/ad7a01
• Publication Date: 2024-10-24T11:37:28Z
• Authors: Jean-Baptiste Vin...; Erik Asphaug; Olivier Barnouin; Joel Beccarelli; Paula G. Benavidez; Adriano Campo-Bag...; Nancy L. Chabot; Carolyn M. Ernst; Pedro H. Hasselmann; Masatoshi Hirabay...; Simone Ieva; Özgür Karatekin; Tomáš Kašpárek; Tomáš Kohout; Zhong-Yi Lin; Alice Lucchetti; Patrick Michel; Naomi Murdoch; Maurizio Pajola; Laura M. Parro; Sabina D. Raducan; Jessica Sunshine; Gonzalo Tancredi; Josep M. Trigo-Ro...; Angelo Zinzi
• Keywords: [SDU] Sciences of the Universe [physics]; asteroids; Astronomy; Dimorphos; [SDU.ASTR.EP] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP]; DART; Astronomy, Space science; QB1-991; [SDU.ASTR] Sciences of the Universe [physics]/Astrophysics [astro-ph]; Asteroids; Didymos; roughness

Abstract Morphological mapping is a fundamental step in studying the processes that shaped an asteroid surface. However, it is challenging and often requires multiple independent assessments by trained experts. Here we present fast methods to detect and characterize meaningful terrains from the topographic roughness: entropy of information, and local mean surface orientation. We apply our techniques to Didymos and Dimorphos, the target asteroids of NASA's Double Asteroid Redirection Test mission—the first attempt to deflect an asteroid. Our methods reliably identify morphological units at multiple scales. The comparative study reveals various terrain types, signatures of processes that transformed Didymos and Dimorphos. Didymos shows the most heterogeneity and morphology that indicate recent resurfacing events. Dimorphos is comparatively rougher than Didymos, which may result from the formation process of the binary pair and past interaction between the two bodies. Our methods can be readily applied to other bodies and data sets.