What do all eight planets of our solar system have in common?

Answer 1

All eight planets have the following features in common:

1. They are in orbit around the Sun
   
2. They have sufficient mass to assume hydrostatic equilibrium (a nearly round shape)
   
3. They have "cleared the neighborhood" around its orbit.

Answer 2

All eight planets in our solar system revolve around the Sun, are spherical in shape, and orbit in roughly the same plane known as the ecliptic. They also have varying compositions of rock and gas, with some having moons and strong magnetic fields.