Ejection of Chondrules from Fluffy Matrices

TL;DR

This study investigates how collisions of fluffy chondrule-matrix aggregates lead to chondrule ejection, challenging the idea that such aggregates can directly form planetesimals without losing chondrules.

Contribution

It demonstrates that fluffy aggregates cannot grow into planetesimals without losing chondrules, suggesting alternative growth pathways are needed for rocky planetesimal formation.

Findings

Fluffy aggregates eject chondrules upon collision.

Direct aggregation of similar-sized aggregates may not form planetesimals.

Alternative growth mechanisms are required for planetesimal formation.

Abstract

Chondritic meteorites primarily contain millimeter-sized spherical objects, the so-called chondrules; however, the co-accretion process of chondrules and matrix grains is not yet understood. In this study, we investigate the ejection process of chondrules via collisions of fluffy aggregates composed of chondrules and matrices. We reveal that fluffy aggregates cannot grow into planetesimals without losing chondrules if we assume that the chondrite parent bodies are formed via direct aggregation of similar-sized aggregates. Therefore, an examination of other growth pathways is necessary to explain the formation of rocky planetesimals in our solar system.