Final Stages of Planet Formation

  title={Final Stages of Planet Formation},
  author={Peter Goldreich and Yoram Lithwick and Re’em Sari},
  journal={The Astrophysical Journal},
  pages={497 - 507}
We address three questions regarding solar system planets: What determined their number? Why are their orbits nearly circular and coplanar? How long did they take to form? Runaway accretion in a disk of small bodies resulted in a tiny fraction of the bodies growing much larger than all the others. These big bodies dominated the viscous stirring of all bodies. Dynamical friction by small bodies cooled the random velocities of the big ones. Random velocities of small bodies were cooled by mutual… 

Theory of planet formation

We review the current theoretical understanding how growth from micro-meter sized dust to massive giant planets occurs in disks around young stars. After introducing a number of observational

Formation of Giant Planet Satellites

Recent analyses have shown that the concluding stages of giant planet formation are accompanied by the development of a large-scale meridional flow of gas inside the planetary Hill sphere. This

Asteroids Were Born Big


Runaway growth is an important stage in planet formation during which large protoplanets form, while most of the initial mass remains in small planetesimals. The amount of mass converted into large

Debris disks as signposts of terrestrial planet formation

There exists strong circumstantial evidence from their eccentric orbits that most of the known extra-solar planetary systems are the survivors of violent dynamical instabilities. Here we explore the


One of the most challenging problems we face in our understanding of planet formation is how Jupiter and Saturn could have formed before the solar nebula dispersed. The most popular model of giant

Dynamical Evolution of Planetary Systems

Planetary systems can evolve dynamically even after the full growth of the planets themselves. There is actually circumstantial evidence that most planetary systems become unstable after the

Terrestrial planet formation in extra-solar planetary systems

  • S. Raymond
  • Physics, Geology
    Proceedings of the International Astronomical Union
  • 2007
Abstract Terrestrial planets form in a series of dynamical steps from the solid component of circumstellar disks. First, km-sized planetesimals form likely via a combination of sticky collisions,

Accretion of Uranus and Neptune from inward-migrating planetary embryos blocked by Jupiter and Saturn

Reproducing Uranus and Neptune remains a challenge for simulations of solar system formation. The ice giants' peculiar obliquities suggest that they both suffered giant collisions during their



Planet formation by coagulation: A focus on Uranus and Neptune

Planets form in the circumstellar disks of young stars. We review the basic physical processes by which solid bodies accrete each other and alter each others' random velocities, and we provide

Making More Terrestrial Planets

The results of 16 new 3D N-body simulations of the final stage of the formation of the terrestrial planets are presented. These Nbody integrations begin with 150‐160 lunar-to-Mars size planetary

The Growth of Planetary Embryos: Orderly, Runaway, or Oligarchic?

We consider the growth of a protoplanetary embryo embedded in a planetesimal disk. We take into account the dynamical evolution of the disk caused by (1) planetesimal-planetesimal interactions, which

Planetesimal Formation by Gravitational Instability

We investigate the formation of planetesimals via the gravitational instability of solids that have settled to the midplane of a circumstellar disk. Vertical shear between the gas and a subdisk of

Rapid collisional evolution of comets during the formation of the Oort cloud

It appears that collisions will prevent most comets escaping from most locations in the region of the giant planets until the disk mass there declines sufficiently that the dynamical ejection timescale is shorter than the collisional lifetime.

Protoplanetary Formation. I. Neptune

Neptune has a gaseous envelope with mass larger than that of the Earth. We examine the possibility that proto-Neptune formed through an initial buildup of a core prior to the accretion of a gaseous