Re: Ideas for World Hierarchy Example

Lew wrote:
>> ... Astronomically speaking, the Earth-Moon system is >> more a double planet than a primary / satellite system.

Neo wrote:
> Considering it's mass is 0.012 that of the Earth, it doesn't meet my
> threshold, but I am no inter-galactic expert. What I will do is add the
> moon's mass, thus allowing applications to make its own decision.
> Earth's mass and circumference is already there.

<http://en.wikipedia.org/wiki/Moon#Physical_characteristics>

"The Earth-Moon system is sometimes considered to be a double planet rather than a planet-moon system. This is due to the exceptionally large size of the Moon relative to its host planet; the Moon is one-fourth the diameter of Earth and 1/81 its mass. However, this definition is criticized by some since the common center of mass of the system (the barycenter) is located beneath the surface of the Earth."

Lew wrote:
>> You might need to add DwarfPlanets.

Neo wrote:
> I opted not to because in the overall scope of the hierarchy, it didn't
> seem important enough. And having just one item under the
> classification of dwarfPlanets seemed wasteful.

<http://en.wikipedia.org/wiki/Dwarf_planet>

"Three dwarf planets are currently recognised: Ceres, Pluto and Eris. Other bodies might be added to the list ..."

• Lew