Ejecta from Hypervelocity Dust Impacts

Ejecta from hypervelocity dust impacts have been shown to depend on the impinging particles' velocity, mass, composition, etc. (Friichtenicht, 1965). Ejecta is thought to be responsible for developing rings and dusty atmospheres of moons throughout the solar system. In order for rings to be produced, dust velocities must be greater than the moon's escape speed. To understand the dust impact yield; impact ejecta parameters (velocities, masses, angular distributions) must be well understood. Laboratory experiments provide direct information about the ejecta production rates and impactor fluxes. Using hypervelocity (1-60km/s) iron dust at the Colorado Center for Lunar Dust and Atmospheric Studies (CCLDAS) dust accelerator in Boulder, Colorado we measured the time characteristics and intensities of light flashes produced on a quartz disc from primary and secondary impacts. The flashes were measured with a photomultiplier tube at varying distances and angles. These measurements provide detailed information about the secondary mass and velocity profiles, leading to insights into the formation of dusty rings and atmospheres.