I suppose that EntityInView can help you.
When an asteroid is no visible to the camera any more then do what ever you want.
You could change also the CameraViewPort (you can make it smaller) to prevent the asteroid hide from the screen.
When an asteroid is no visible to the camera any more then do what ever you want.
You could change also the CameraViewPort (you can make it smaller) to prevent the asteroid hide from the screen.