Chemical compositions in impact-generated vapor clouds explored by impact experiments

Abstract

Hypervelocity impacts on the early Earth during the heavy bombardment period are expected to lead unique chemical reactions, which have never been driven on the mean reaction fields on the Earth. The quantitative determinations of injection fluxes of various chemical species on the surface environment is necessary to understand how the chemical evolutions had proceed on the early Earth. We also expect that signatures of such impacts might be fixed in impact-related stratifications as unique geochemical products, such as the spherule beds. We are developing a new experimental system to explore the nature of impact-induced chemical reactions using a two-stage light gas gun. The new system allows us to investigate the final gas products in an open system after hypervelocity impacts at ranged from 1 km/s to 7 km/s. We will present the experimental results with water ice and calcite targets at the conference. We can accelerate any projectile with 2 mm in diameter and shoot onto targets with any chemical compositions and can measure final gas products with the proposed method.