Enhancement of impact heating in pressure-strengthened rocks in oblique impacts

TL;DR

This study uses 3D oblique impact simulations to demonstrate that material strength enhances impact heating, revealing that oblique impacts generate comparable heated mass to head-on impacts despite lower peak pressures, due to shear heating effects.

Contribution

It provides new insights into impact heating mechanisms in oblique impacts, emphasizing the role of shear heating and challenging previous assumptions about heated mass reduction with impact obliquity.

Findings

Heated mass in oblique impacts is similar to head-on impacts.

Shear heating is more effective in oblique impacts.

Ejected material experiences lower shock pressures but higher temperatures.

Abstract

Shock-induced metamorphism in meteorites informs us about the collisional environment and history of our solar system. Recently the importance of material strength in impact heating was reported from head-on impact simulations. Here, we perform three-dimensional oblique impact simulations, and confirm the additional heating due to material strength for oblique impacts. Despite a large difference in the peak pressure at the impact point at a given impact velocity, we find that the heated mass for an oblique impact is nearly the same as that for a head-on impact. Thus, our results differ from the previous finding that the heated mass decreases as the impact becomes more oblique, and show that the additional shear heating is more effective for oblique impacts than for head-on impacts. This also indicates that material ejected during oblique impact tends to experience lower shock pressures but higher temperatures.