public void pauseObjects(){
		if (player1 != null)
			player1.pause();
		if (player2 != null)
			player2.pause();
		for (Asteroid asteroid: asteroids)
			asteroid.pause();
		for (Bullet bullet: bullets)
			bullet.pause();
		if (alienShip != null)
			alienShip.pause();
		if (rogueSpaceship != null)
			rogueSpaceship.pause();
	}