Effect of impact velocity and angle on deformational heating and post-impact temperature

TL;DR

This study uses 3D impact simulations to analyze how impact angle and velocity influence shock-heating in meteorites, providing empirical formulas to estimate impact conditions and implications for meteorite heating and shock features.

Contribution

It introduces a new empirical formula relating impact angle and velocity to heated mass, enhancing understanding of impact heating effects in meteorites.

Findings

Oblique impacts steeper than 45° produce similar heated mass as vertical impacts.

Grazing impacts produce less heated material and smaller heated regions.

Higher velocity grazing impacts can generate comparable heated material to lower velocity vertical impacts.

Abstract

The record of impact induced shock-heating in meteorites is an important key for understanding the collisional history of the solar system. Material strength is important for impact heating, but the effect of impact angle and impact velocity on shear heating remains poorly understood. Here, we report three-dimensional oblique impact simulations, which confirm the enhanced heating due to material strength and explore the effects of impact angle and impact velocity. We find that oblique impacts with an impact angle that is steeper than 45 degree produce a similar amount of heated mass as vertical impacts. On the other hand, grazing impacts produce less heated mass and smaller heated regions compared to impacts at steeper angles. We derive an empirical formula of the heated mass, as a function of the impact angle and velocity. This formula can be used to estimate the impact conditions (velocity and angle) that had occurred and caused Ar loss in the meteoritic parent bodies. Furthermore, our results indicate that grazing impacts at higher impact velocities could generate a similar amount of heated material as vertical impacts at lower velocities. As the heated material produced by grazing impacts has experienced lower pressure than the material heated by vertical impacts, our results imply that grazing impacts may produce weakly shock-heated meteorites.