Insight into the Distribution of High-pressure Shock Metamorphism in Rubble-pile Asteroids

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985831%3A_____%2F22%3A00562160" target="_blank" >RIV/67985831:_____/22:00562160 - isvavai.cz</a>

Výsledek na webu

<a href="https://iopscience.iop.org/article/10.3847/PSJ/ac83c0" target="_blank" >https://iopscience.iop.org/article/10.3847/PSJ/ac83c0</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/PSJ/ac83c0" target="_blank" >10.3847/PSJ/ac83c0</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Insight into the Distribution of High-pressure Shock Metamorphism in Rubble-pile Asteroids

Popis výsledku v původním jazyce

Shock metamorphism in ordinary chondrites allows for reconstructing impact events between asteroids in the main asteroid belt. Shock-darkening of ordinary chondrites occurs at the onset of complete shock melting of the rock (>70 GPa) or injection of sulfide and metal melt into the cracks within solid silicates (∼50 GPa). Darkening of ordinary chondrites masks diagnostic silicate features observed in the reflectance spectrum of S-complex asteroids so they appear similar to C/X-complex asteroids. In this work, we investigate the shock pressure and associated metamorphism pattern in rubble-pile asteroids at impact velocities of 4–10 km s−1. We use the iSALE shock physics code and implement two-dimensional models with simplified properties in order to quantify the influence of the following parameters on shock-darkening efficiency: impact velocity, porosity within the asteroid, impactor size, and ejection efficiency. We observe that, in rubble-pile asteroids, the velocity and size of the impactor are the constraining parameters in recording high-grade shock metamorphism. Yet, the recorded fraction of higher shock stages remains low (<0.2). Varying the porosity of the boulders from 10% to 30% does not significantly affect thedistribution of pressure and fraction of shock-darkened material. The pressure distribution in rubble-pile asteroids is very similar to that of monolithic asteroids with the same porosity. Thus, producing significant volumes of highdegree shocked ordinary chondrites requires strong collision events (impact velocities above 8 km s−1 and/or large sizes of impactors). A large amount of asteroid material escapes during an impact event (up to 90%), however, only a small portion of the escaping material is shock-darkened (6%).

Název v anglickém jazyce

Insight into the Distribution of High-pressure Shock Metamorphism in Rubble-pile Asteroids

Popis výsledku anglicky

Shock metamorphism in ordinary chondrites allows for reconstructing impact events between asteroids in the main asteroid belt. Shock-darkening of ordinary chondrites occurs at the onset of complete shock melting of the rock (>70 GPa) or injection of sulfide and metal melt into the cracks within solid silicates (∼50 GPa). Darkening of ordinary chondrites masks diagnostic silicate features observed in the reflectance spectrum of S-complex asteroids so they appear similar to C/X-complex asteroids. In this work, we investigate the shock pressure and associated metamorphism pattern in rubble-pile asteroids at impact velocities of 4–10 km s−1. We use the iSALE shock physics code and implement two-dimensional models with simplified properties in order to quantify the influence of the following parameters on shock-darkening efficiency: impact velocity, porosity within the asteroid, impactor size, and ejection efficiency. We observe that, in rubble-pile asteroids, the velocity and size of the impactor are the constraining parameters in recording high-grade shock metamorphism. Yet, the recorded fraction of higher shock stages remains low (<0.2). Varying the porosity of the boulders from 10% to 30% does not significantly affect thedistribution of pressure and fraction of shock-darkened material. The pressure distribution in rubble-pile asteroids is very similar to that of monolithic asteroids with the same porosity. Thus, producing significant volumes of highdegree shocked ordinary chondrites requires strong collision events (impact velocities above 8 km s−1 and/or large sizes of impactors). A large amount of asteroid material escapes during an impact event (up to 90%), however, only a small portion of the escaping material is shock-darkened (6%).

Druh

J_SC - Článek v periodiku v databázi SCOPUS

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2022

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

The Planetary Science Journal

ISSN

2632-3338

e-ISSN

2632-3338

Svazek periodika

3

Číslo periodika v rámci svazku

8

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

12

Strana od-do

198

Kód UT WoS článku

000912991700001

EID výsledku v databázi Scopus

2-s2.0-85142020062