Title: Simulations of high-velocity impacts on metal in preparation for the Psyche mission

Abstract

In 2026, the NASA Discovery mission Psyche will orbit the asteroid (16) Psyche, the largest known metal-rich asteroid in the main belt. To estimate relative ages of the surface, identify re-surfacing events and better constrain Psyche's history, impact craters will be counted and characterized. No spacecraft has ever visited a metal-rich small body; therefore, laboratory-scale impact experiments and numerical simulations will play an important role in the interpretation of the mission's data. However, the planetary applications of high-velocity impacts have so far mostly been studied for silicate targets. Limited attention has been drawn to planetary objects predominantly made of metal, and more laboratory experiments and numerical calibrations are needed. As part of this effort, we present a suite of numerical simulations using an adaptative smoothed particles hydrodynamics numerical code (ASPH) reproducing a high-velocity impact experiment conducted on a steel target. This work primarily focuses on the influence of the chosen equation of state and initial distribution of flaws in the material on the estimated crater dimensions, damage and temperature. Additionally, we find that changing the EOS and initial flaw distribution affects the crater dimensions, though for a vast majority of cases the dimensions remain within 20% of the experimental values.more » The target is in most cases only locally weakened but not fully damaged, independently from the EOS chosen. Finally, temperatures at the impact point and around the forming crater can reach values above the melting point of iron at <100 GPa, which is in agreement with experimental observations. These results allow us to speculate on the differences expected between the surfaces of visited silicate-rich asteroids and that of the metal-rich target of the Psyche mission.« less

Authors:

Maurel, Clara ^[1]; Michel, Patrick ^[2]; Owen, J. Michael ^[3]; Binzel, Richard P. ^[1]; Bruck-Syal, Megan ^[3]; Libourel, G. ^[2]

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+ Show Author Affiliations

1. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
2. Univ, Côte d'Azur, Nice (France), Observatoire de la Côte d'Azur, CNRS, Laboratoire Lagrange
3. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

Publication Date:

Sat Nov 09 00:00:00 EST 2019

Research Org.:

Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

Sponsoring Org.:

USDOE National Nuclear Security Administration (NNSA)

OSTI Identifier:

1837810

Alternate Identifier(s):

OSTI ID: 1698073

Report Number(s):

LLNL-JRNL-821463
Journal ID: ISSN 0019-1035; 1032782; TRN: US2300505

Grant/Contract Number:  

AC52-07NA27344

Resource Type:

Accepted Manuscript

Journal Name:

Icarus

Additional Journal Information:

Journal Volume: 338; Journal ID: ISSN 0019-1035

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

79 ASTRONOMY AND ASTROPHYSICS; 58 GEOSCIENCES; 36 MATERIALS SCIENCE