Final Stages of Planet Formation

  title={Final Stages of Planet Formation},
  author={Peter Goldreich and Yoram Lithwick and Re’em Sari},
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… CONTINUE READING