Initial Accretion of Chondrule Fine-grained Rims due to High Speed Dust Impact

The structure of chondritic meteorites often contains chondrules and a fine-grained dust matrix known as a fine-grained rim (FGR). The process by which the fine-grained rim formed in the pre-solar nebula or protoplanetary disk is not fully understood. One possible answer is that high speed collisions of dust into a chondrule surface causes the dust to fracture and compact into the surface. We test this theory by making numerical simulations with the iSALE-2D shock physics code to model the impact between the dust grains and the chondrule surface. The speed of the dust impacting the chondrule surface is varied, and the change in density of the chondrule and initial fine-grained rim by the impacting dust is measured, which is used to measure the mass accretion of dust onto the chondrule surface. This allows us to see whether mass is gained or mass is lost at different speeds, providing a clue to the processes that helped form our solar system.