TURBULENCE, PEBBLES AND PLANETESIMALS : THE ORIGIN OF MINOR BODIES IN THE SOLAR SYSTEM

The Minor Bodies of the Solar System, Asteroids, Trojans, Comets and Kuiper Belt Objects are left over planetary building bricks called planetesimals once abundant in the solar nebula. Via collisions and accretion of large grains, aka Pebbles, they grew into planets.

The efficiency of Planetesimals formation via a gravitational collapse of Pebble clouds and the characteristics of the forming planetesimals are determined by the size distribution and local concentration of the largest grains, both being regulated by gas turbulence.

But turbulence itself is dependent on the abundance of small grains, by regulating the ionisation level and the radiative cooling process.In this project we will develop radically new types of numerical experiments of three stages of planetesimal formation, with the goal of a self-consistent turbulence and pebble size distribution:1.

Development of tools to measure the transport, diffusion, and collisions of dust grains for arbitrary MHD or Radiation Hydro disk simulations to derive via an Coagulation Code and Machine Learning Technique a consistent particle size distribution for consistent opacities and ionisation rates to feed back into the turbulence simulation. 2.

Implementation of a tree-solver for the gravitational attraction among pebbles in self-consistent turbulence simulations to identify the properties of pebble clouds that can undergo gravitational collapse. 3.

Integration of an implicit solver for our Lagrangian Particle scheme to model the collapse of pebble clouds, while not only deriving a mass function and multiplicity, but with a model for elasticity and porosity analyse the spin, shape, and compression for the forming planetesimals, comets and asteroids.In close collaboration with our scientific community we will calibrate our turbulence models and the planetesimal formation process on the observation of disks around young stars as well as observational and laboratory data on Minor Bodies in the Solar System.