The terrestrial planets are small,
not very massive but dense,
close to the Sun and have few moons.
They have rocky outer parts and iron cores.
– A. Filippenko, slide CS-95, fall 2009
The Jovian planets are large, massive
but not very dense, far from the Sun,
and have many moons. They are
mostly liquid, but have rock/iron
cores. They rotate rapidly.
– A. Filippenko, slide CS-111, fall 2009