void PlanetTree_SelectedItemChanged(object sender, RoutedPropertyChangedEventArgs <object> e)
{
var body = e.NewValue as CelestialObject;
if (body == null)
{
return;
}
var mapIcon = MapCanvas.Children.OfType <IMapIcon>().Single(icon => icon.Body == body);
var childCoords = new Point(mapIcon.X, mapIcon.Y);
ZoomControl.ZoomAndCenter(0.25, ZoomControl.ChildToParent(childCoords));
}