Planetesimals Dynamics#


Introduction

Intro paragraph

Plan


  • Summary

Notes

Page

  • Status: flag alt >

  • Reviewed: ❌

  • Updated: 15/02/2023

Planetesimals#

  • [Weidenschilling, 1980]: numerical model for computing simultaneous coagulation and settling (gravitational instability/non-Keplerian rotation of nebula), composite process forms km sized planetesimals

Disk instabilities#

  • [Johansen et al., 2014]: hybrid model for planetesimal formation (particle growth starts unaided by self-gravity but later proceeds inside gravitationally collapsing pebble clumps to form planetesimals with a wide range of sizes)

../../_images/Disk-instability-Johansen.png

Note

define all those terms


Overcoming The Bouncing Barrier#


2 Scenarios:

  • Gravitational instability

  • Mass transfer

cf [Blum et al., 2014] for good introduction + Modelling and experiments on dust emission from comets etc., homogeneous layers of μm sized dust particles reach tensile strengths (103 – 104 Pa) far higher than water’s sublimation pressure, model of formation by gravitational instability leads to tensile strength of 1 Pa instead => could explain water driven comet activity (minimum size for dust-aggregates: ≈ 1 mm) => cometesimals must have formed by gravitational instability


Gravitational collapse ?#

[Aumatell and Wurm, 2011]: Lab experiments, sublimation of freely levitating ice aggregates, frequent break up, sublimation of drifting ice aggregates might locally increase the density of small dust (silicate)

Title#

Let’s jump over the Bouncing Barrier and have a look at thos km bodies that may have formed.

Planetesimals#

Dynamic Evolution of the Early Solar System#

[Nesvorn´y and Nesvorn´y, 2018]

Overcoming the bouncing barrier#

Electrical charging#

Growth Mechanism#

Sintering ? #

[Okuzumi et al., 2016] (mention ethane in their paper)

  • [Sirono, 2011]: Sintering increases strength of neck in aggregates, sintering region can span whole nebula

  • [Sirono, 2011]: Numerical simulations (sintering of icy dust aggregates), accumulation of fragments in particular region of protoplanetary nebula, planetesimal formation by gravitational instability

Rocky Planet formation#

[Burkhardt et al., 2021] : Two different scenarios for rocky planet formation

From planet formation to planet atmosphere#

[Mollière et al., 2022]