Simultaneous detection of the size and velocity of the largest ejecta particles with velocities exceeding 1 km s$^{-1}$

TL;DR

This paper introduces a new method to simultaneously measure the size and velocity of high-velocity ejecta particles, revealing their potential to escape planetary bodies and contribute to interplanetary dust populations.

Contribution

The study presents a novel experimental approach combining high-speed imaging and crater analysis to determine size-velocity relationships of ejecta exceeding 1 km/s.

Findings

Millimeter-sized meteoroids can eject sub-100 micrometer particles at velocities over 1 km/s.

Ejecta velocities can surpass planetary escape velocities, contributing to interplanetary dust.

The method enables precise measurement of ejecta parameters at high velocities.

Abstract

Impact ejecta with velocities exceeding the escape velocity of planetary bodies become meteorites and dust particles in interplanetary space. We present a new method that allows simultaneous measurement of the size and velocity of the largest high-velocity ejecta. High-speed camera images revealed the time required for the ejecta to reach the secondary target, and ejecta size was determined after the experiment by analyzing the craters formed upon their impact on the secondary target. We defined the size-velocity relationships of sub-millimeter ejecta with velocities exceeding 1 km s$^{-1}$, focusing on the largest detectable ejecta in our experiments. The results show that millimeter-sized meteoroids impacting the rocky surfaces of planetary bodies at 7 km s$^{-1}$ eject particles up to a few tens of micrometers in size toward interplanetary space at velocities exceeding the escape velocity of the body, even when it is greater than 1 km s$^{-1}$.