Diameter

Diameter is used to describe the sizes of planets and moons. The diameter is used in game to determine the following:
 * Number of fields on a planet
 * Number of fields on a moon
 * The outcome of an attempt to destroy a moon with Death Stars

The formula for the number of fields on a planet or moon is:


 * $$\left(\frac{\mathrm{Diameter}}{1000}\right)^2$$

This result is rounded down (for example, 25.629 becomes 25 fields.) In addition, your home planet is always 163 fields regardless of diameter.

When attacking a moon with one or more Death Stars, the chance that the moon will be destroyed is:


 * $$(100-\sqrt{\mathrm{Diameter}})\sqrt{\mbox{Number of Death Stars}}$$

There is also a chance that the attacking Death Stars and any other ships in the fleet will be destroyed. The chance of this occurring is:


 * $$\frac{\sqrt{\mathrm{Diameter}}}{2}$$

These formulas are taken from the on the Forum.