Planetesimal formation in the outer solar nebula

accretion aggregates asteroid belt CAIs Cconv cell grid Chapter chondrules circumstellar disk cm s_1 coagulation coefficient of restitution collisions constant convective cells convective velocities core Cuzzi decrease disk height disk pendulum drag regime eddy Equation gas density gas drag forces gravitational ice brick iceball icy grains icy mantle impact increase initial kinetic energy Kolmogorov convection laminar nebula larger particles mass density maximum mean free path meteorites midplane mm-sized nebular gas nebular radii number density Orbital trajectories orbiting particle orders of magnitude outer solar nebula panel of Figure Particle lifetime Particle orbits particle radius particle surface particle temperature particles grow phase planetesimal formation planets protoplanets radial velocity relative velocity scale height Section significantly small particles smaller solar gravity solar value solid static convection sticking force sublimation radius Supulver surface density Tauri stars terrestrial planets timescale timestep torsion pendulum trapped turbulent cells turbulent nebula vertical vrei