Is there a reason why we have four “rock” planets lined up followed by four “gas” planets in a row, or is it merely coincidence?

Question

Is there a reason why we have four “rock” planets lined up followed by four “gas” planets in a row, or is it merely coincidence?

In: Planetary Science

Answer 1

Fill a glass with cold water. Add a heaping scoop of Tang (or whatever). Give it a good whirl. What do you see?

You get a pile of the ~~bigger~~ denser bits in the middle.

ipso facto.

(I actually have no idea, thanks for asking)