Understanding Asteroid 16 Psyche’s composition through 3D impact crater modeling

• Published in: Icarus (New York, N.Y. 1962) Vol. 351; p. 113962
• Main Authors: Caldwell, Wendy K., Hunter, Abigail, Plesko, Catherine S., Wirkus, Stephen
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15-11-2020; Elsevier
• Subjects: Asteroid 16 Psyche; ASTRONOMY AND ASTROPHYSICS; FLAG; impact cratering
• ISSN: 0019-1035; 1090-2643
• DOI: 10.1016/j.icarus.2020.113962

Asteroid 16 Psyche is the largest M-type (metallic) Main Belt Asteroid (MBA). Radar albedo data indicate Psyche’s surface is rich in metallic content, but estimates for Psyche’s bulk structure vary widely, with bulk density estimates ranging from 1.4 ± 0.3 g/cm3 to 4.5 ± 1.4 g/cm3 and porosity estimates ranging from 30% to 70%. A forthcoming NASA discovery mission will visit Psyche. Narrowing the range of estimated compositions of Psyche prior to mission launch can help to determine the necessary tools for asteroid analysis. Psyche has two large impact structures in its Southern hemisphere, with estimated diameters from 50 km to 70 km and estimated depths up to 6.4 km. In this work, we present results from 2D and 3D hydrocode simulations of the largest of these impact structures. Through quantitative comparison of the simulated crater dimensions with measured values, our models suggest that Psyche is largely composed of porous, metallic material. In addition, to match the crater dimensions, our simulations indicate that the angle of impact was significantly altered from vertical by 45–60 degrees.
•First (to our knowledge) 3D models of formation of Psyche’s largest impact crater.•First (to our knowledge) work to use impact crater models to inform asteroid composition.•2D and 3D models indicate oblique impact angle.•2D and 3D models indicate Psyche is likely metallic and porous in composition, though unlikely to be have porosity of 60% or greater.•3D simulation with depths and diameters within the uncertainties used Monel as the target and impactor material, and impact angle 60°from vertical, and porosities on Psyche of 30% – 50%.