# Growing into and out of the bouncing barrier in planetesimal formation

## TL;DR

This study demonstrates that in planetesimal formation, dust aggregates can grow into and out of the bouncing barrier through a self-consistent process involving hit-and-stick mechanisms and dust supply, affecting their size evolution.

## Contribution

It reveals that the bouncing barrier is dynamic, allowing aggregates to both grow into and out of it via interactions with smaller dust particles.

## Key findings

- Bouncing barrier evolves through hit-and-stick from smaller dust aggregates.
- Feeding small aggregates temporarily increases stickiness.
- Aggregate size can increase beyond the bouncing barrier with dust supply.

## Abstract

In recent laboratory studies the robustness of a bouncing barrier in planetesimal formation was studied with an ensemble of preformed compact mm-sized aggregates. Here we show that a bouncing barrier indeed evolves self-consistently by hit-and-stick from an ensemble of smaller dust aggregates. In addition, we feed small aggregates to an ensemble of larger bouncing aggregates. The stickiness temporarily increases, but the final number of aggregates still bouncing remains the same. However, feeding on the small particle supply, the size of the bouncing aggregates increases. This suggests that in the presence of a dust reservoir aggregates grow into but also out of a bouncing barrier at larger size.