private async void ViewWorldButton_Clicked(object sender, EventArgs e)
 {
     if (CurrentStarSystem == null)
     {
         await DisplayAlert("Warning", "Please generate a system first.", "OK");
     }
     else
     {
         var worldView = new PlanetView(CurrentStarSystem.Mainworld, Config);
         await Navigation.PushAsync(worldView);
     }
 }
 private async void Satellites_ItemSelected(object sender, SelectedItemChangedEventArgs e)
 {
     var planet       = e.SelectedItem as Planet;
     var planetViewer = new PlanetView(planet, _configuration);
     await Navigation.PushAsync(planetViewer);
 }