Abstract DGP2026-64

Impact simulations of the DART impact – on the influence of interior properties

Robert Luther (1), Cem Berk Senel (2,3), Özgür Karatekin (3), Gareth S. Collins (4), Steven Goderis2, Philippe Claeys (2), Kaiyi Dai (1), Kai Wünnemann (1,5)

(1) Museum für Naturkunde - Leibniz Institute for Evolution and Biodiversity Science, Berlin, Germany (2) Archaeology, Environmental Changes, & Geochemistry (AMGC) - Vrije Universiteit Brussel, Belgium (3) Reference Systems & Planetology Department - Royal Observatory of Belgium, Brussels, Belgium (4) Department of Earth Science and Engineering, Imperial College London, London, UK (5) Institute of Geological Sciences, Freie Universität,Berlin, Germany

On 26th of September 2022 at 23:14:24 (UTC), NASA’s DART spacecraft impacted the secondary of the 65803 Didymos system, Dimorphos [1]. Its impact shortened the orbit of Dimorphos by 33 minutes to 11.37 h [2]. The change of the orbit is caused by a change of Dimorphos’ momentum due to the impact. A fraction of the momentum change related to the transfer of the spacecraft momentum. The more important fraction of momentum is caused by the ejection of material from Dimorphos, which is dependent on the material properties. To explore this influence, we simulated a series of DART-scale hypervelocity impacts using the two-dimensional axisymmetric (2DC) version of the iSALE shock physics code [3-5]. In specific, we use a Drucker-Prager strength model, varying the cohesion from 1 – 1000 Pa, and the internal friction between 0.4 – 0.7. The range of tested porosity is 10-50%. We also ran simulations adding boulders to the setup. The representation of boulders in 2D is difficult, because boulders are 3D objects. We test a 2D approximation of 3D objects [6].

Homogeneous cases with low cohesions (20–80 Pa) and a coefficient of friction of 0.5 matched the reference momentum enhancement, but is not a unique solution. We also find that our 2D approximation of 3D boulders reproduces trends of the momentum enhancement from full 3D iSALE models for a range of DART-like boulder setups [7].

[1] Daly et al. (2023), Nature 616,443.

[2] Thomas et al. (2023), Nature 616,448.

[3] Amsden et al. (1980), LANL Report, LA-8095:101p., New Mexico.

[4] Collins et al. (2004), M&PS, 39(2), 217-231.

[5] Wünnemann et al. (2006), Icarus, 180(2), 514-527.

[6] Senel et al. (2025), The Planetary Science Journal, 6:157.

[7] Senel et al. (2026), MNRAS 545, 1-16.