Planets
As of now, Planets are a subtype of Orbiting Objects with no additional functions.
Moons
Moons are a subtype of Planets, but have one additional property which Planets don't have.
{"parent": "stellarview:planet/milky_way/sol/earth","coords": { "x": {"ly": 0}, "y": {"ly": 0}, "z": {"ly": 0} },"axis_rotation": { "x_axis": 0, "y_axis": 0, "z_axis": 0 },"orbit_info":{"apoapsis": 405400,"periapsis": 362600,"orbit_clamp_distance": 100000000,"orbital_period": { "ticks": 192000, "synodic": true },"argument_of_periapsis": 0,"inclination": 5.145,"longtitude_of_ascending_node": 0,"epoch_mean_anomaly": 157.5},"texture_layers":[{"texture": "stellarview:textures/environment/moon_halo_phases.png","rgba": {"red": 255, "green": 255, "blue": 255, "alpha": 255},"blend": true,"size": 7697847.735118539,"min_size": 0.15,"clamp_at_min_size": true,"rotation": 90,"uv":{"phase_handler":{"ticks_per_phase": 24000,"phase_tick_offset": 0,"columns": 4,"rows": 2},"flip_uv": true}},{"texture": "stellarview:textures/environment/moon_phases.png","rgba": {"red": 255, "green": 255, "blue": 255, "alpha": 255},"blend": false,"size": 7697847.735118539,"min_size": 0.15,"clamp_at_min_size": true,"rotation": 90,"uv":{"phase_handler":{"ticks_per_phase": 24000,"phase_tick_offset": 0,"columns": 4,"rows": 2},"flip_uv": true}}],"compatibility":{"enhanced_celestials_moon_dimension": "minecraft:overworld"}}
In the above example, we see the definition of Luna. We can see a field called compatibility. This field is used for compatibility with Enhanced Celestials and specifies the Dimension in which the visual effects (changing size and color) for a Moon added by Enhanced Celestials will become apparent.