* An inclination of exactly 90° is a polar orbit, in which the spacecraft passes over the poles of the planet.
* An inclination greater than 90° and less than 180° is a retrograde orbit.
* An inclination of exactly 180° is a retrograde equatorial orbit.

For impact-generated moons of terrestrial planets not too far from their star, with a large planet-moon distance, the orbital planes of moons tend to be aligned with the planet's orbit around