The shock physics of giant impacts: Key requirements for the equations of state

Sarah T Stewart; Erik Davies; Megan Duncan; Simon Lock; Seth Root; Joshua Townsend; Richard G. Kraus; Razvan Caracas; Stein B. Jacobsen

doi:10.1063/12.0000946

The shock physics of giant impacts: Key requirements for the equations of state

Sarah T Stewart^*, Erik Davies, Megan Duncan, Simon Lock, Seth Root, Joshua Townsend, Richard G. Kraus, Razvan Caracas, Stein B. Jacobsen

^*Corresponding author for this work

School of Earth Sciences

Research output: Chapter in Book/Report/Conference proceeding › Conference Contribution (Conference Proceeding)

42 Citations (Scopus)

Abstract

We discuss major challenges in modeling giant impacts between planetary bodies, focusing on the equations of state (EOS). During the giant impact stage of planet formation, rocky planets are melted and partially vaporized. However, most EOS models fail to reproduce experimental constraints on the thermodynamic properties of the major minerals over the required phase space. Here, we present an updated version of the widely-used ANEOS model that includes a user-defined heat capacity limit in the thermal free energy term. Our revised model for forsterite (Mg2SiO4), a common proxy for the mantles of rocky planets, provides a better fit to material data over most of the phase space of giant impacts. We discuss the limitations of this model and the Tillotson equation of state, a commonly used alternative model.

Original language	English
Title of host publication	American Institute of Physics Conference Proceedings
Publisher	American Institute of Physics (AIP)
Volume	2272
DOIs	https://doi.org/10.1063/12.0000946
Publication status	Published - 4 Nov 2020

Keywords

giant impact
Thermodynamics
equation of state
shock wave physics

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title = "The shock physics of giant impacts: Key requirements for the equations of state",

abstract = "We discuss major challenges in modeling giant impacts between planetary bodies, focusing on the equations of state (EOS). During the giant impact stage of planet formation, rocky planets are melted and partially vaporized. However, most EOS models fail to reproduce experimental constraints on the thermodynamic properties of the major minerals over the required phase space. Here, we present an updated version of the widely-used ANEOS model that includes a user-defined heat capacity limit in the thermal free energy term. Our revised model for forsterite (Mg2SiO4), a common proxy for the mantles of rocky planets, provides a better fit to material data over most of the phase space of giant impacts. We discuss the limitations of this model and the Tillotson equation of state, a commonly used alternative model.",

keywords = "giant impact, Thermodynamics, equation of state, shock wave physics",

author = "Stewart, {Sarah T} and Erik Davies and Megan Duncan and Simon Lock and Seth Root and Joshua Townsend and Kraus, {Richard G.} and Razvan Caracas and Jacobsen, {Stein B.}",

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T1 - The shock physics of giant impacts: Key requirements for the equations of state

AU - Stewart, Sarah T

AU - Davies, Erik

AU - Duncan, Megan

AU - Lock, Simon

AU - Root, Seth

AU - Townsend, Joshua

AU - Kraus, Richard G.

AU - Caracas, Razvan

AU - Jacobsen, Stein B.

PY - 2020/11/4

Y1 - 2020/11/4

N2 - We discuss major challenges in modeling giant impacts between planetary bodies, focusing on the equations of state (EOS). During the giant impact stage of planet formation, rocky planets are melted and partially vaporized. However, most EOS models fail to reproduce experimental constraints on the thermodynamic properties of the major minerals over the required phase space. Here, we present an updated version of the widely-used ANEOS model that includes a user-defined heat capacity limit in the thermal free energy term. Our revised model for forsterite (Mg2SiO4), a common proxy for the mantles of rocky planets, provides a better fit to material data over most of the phase space of giant impacts. We discuss the limitations of this model and the Tillotson equation of state, a commonly used alternative model.

AB - We discuss major challenges in modeling giant impacts between planetary bodies, focusing on the equations of state (EOS). During the giant impact stage of planet formation, rocky planets are melted and partially vaporized. However, most EOS models fail to reproduce experimental constraints on the thermodynamic properties of the major minerals over the required phase space. Here, we present an updated version of the widely-used ANEOS model that includes a user-defined heat capacity limit in the thermal free energy term. Our revised model for forsterite (Mg2SiO4), a common proxy for the mantles of rocky planets, provides a better fit to material data over most of the phase space of giant impacts. We discuss the limitations of this model and the Tillotson equation of state, a commonly used alternative model.

KW - giant impact

KW - Thermodynamics

KW - equation of state

KW - shock wave physics

UR - http://dx.doi.org/10.1063/12.0000946

UR - https://arxiv.org/abs/1910.04687

U2 - 10.1063/12.0000946

DO - 10.1063/12.0000946

M3 - Conference Contribution (Conference Proceeding)

VL - 2272

BT - American Institute of Physics Conference Proceedings

PB - American Institute of Physics (AIP)

ER -

The shock physics of giant impacts: Key requirements for the equations of state

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