public void ColonizePlanet(Ship whichShip)
{
//This assumes that whichShip is not null, adjacentSystem is not null, and everything has already been validated (i.e. ship has correct colony pod)
ships[whichShip]--;
if (ships[whichShip] == 0)
{
//only one ship, so remove the entry for it
ships.Remove(whichShip);
_orderedShips.Remove(whichShip);
}
_adjacentSystem.Planets[0].Colonize(_empire);
}