The 41/2 Steps of Terrestrial Planet Formation in the Solar System. (cont)
Step III: Oligarchic
Growth (Kokubo & Ida 1998)
- Recall that as long as is not affected by M.
- As the big guys grow, they have a larger fraction of system mass stir small guys.
- So, growth slows.
- Studies have shown that (Kokubo & Ida):
- The largest few objects at any given time are:
- of comparable mass
- separation is ~10RH, (Earth: RH=0.01AU)
where RH is the gravitational sphere of influence and is f(M,a).
- So, as the system evolves:
- Number of big guys decreases.
- Their masses increase.
- Their separation increases.