Planets

Ok, because I don't like the "round and orbiting" definition of the Astronomical Union, here is my own definition of a planet:

#1: It must have a gravitational pull, at its surface, of at least 1m/s². The size definition of 480 miles doesn't take into consideration variations in density.

#2: It must have an atmospheric pressure of more than 0.25 kPa at surface.

(For planets with no discernable surface, #2 is assumed to be met, and #1 is assumed if the planet's diameter, with atmosphere, is larger than 10,000 km)

#3: It must orbit a star with a Perihelion of at least 75% the distance of its Aphelion. (OR if the planet is also a satellite of another non-star object (known as the "core object"), the core object must meet the requirements of #3.)

This would reclassify the solar system as follows:
Mercury: not a planet
Venus: planet
Earth: planet
Moon: not a planet
Mars: planet
Mars' satellites: not planets
Ceres & asteroids: not planets
Jupiter: planet
Jupiter's moons: not planets
Saturn: planet
Titan: planet
Saturn's other moons: not planets
Uranus: planet
Uranus's moons: not planets
Neptune: planet
Neptune's moons (including triton): not planets
Pluto, Charon, and other Kuiper Belt objects: not planets Sphere: Related Content