Exploring density and strength variations in asteroid 16 Psyche’s composition with 3D hydrocode modeling of its deepest impact structure

Journal Article · 17 October 2023 · Icarus

DOI: https://doi.org/10.1016/j.icarus.2023.115780 · OSTI ID:2229693

Caldwell, Wendy K.  ^[1]; Hunter, Abigail  ^[1]; Plesko, Catherine S.  ^[1]

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1. Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

Asteroid 16 Psyche is the largest metallic Main Belt Asteroid and is the subject of a forthcoming NASA mission. The composition of Psyche is still unknown and subject of recent debate. In particular, how much porosity is within Psyche, along with how much of Psyche consists of non-metallic versus metallic materials, are central questions to the issue of Psyche’s composition. If Psyche is indeed predominantly composed of metallic materials, it would need to have considerable porosity (~ 30%–50%) for a composition consistent with its expected bulk density (~ 3.7–4.1 g/cm). In this work, we vary the density and strength of Psyche by including uniform and layered fields of pseudo-microporosity, in addition to investigating the presence of macroscopic voids, i.e., spaces larger than the size of the simulation’s mesh cells, in rubble-pile configurations. Further, all configurations result in bulk densities within the uncertainties of measured values, however the strength of Psyche and the distribution of pseudo-pores are varied. Through 3D computational models of Psyche’s deepest impact structure, we show that Psyche’s composition is unlikely to contain only pseudo-microporosity. Rather, rubble pile structures, which include macroscopic voids, are shown to match the crater’s measured aspect ratio better than simulations of structures that included only pseudo-microporosity.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR); USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: 89233218CNA000001
• OSTI ID: 2229693
• Report Number(s): LA-UR--21-30361
• Journal Information: Icarus, Journal Name: Icarus Vol. 408; ISSN 0019-1035
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English