There is a difference between “Heaven” and “the heavens.” The heavens include the sky, the universe, the stars, the planets, and the galaxies. All of those things, you can see either with the naked eye, or with a telescope. Heaven is a different matter, entirely. We know from Scripture that it is a real place and that it will last forever. But, we also know that it is not fully understandable. It is outside of our universe, maybe in a completely spiritual place. We cannot see it, nor can we get to it by human means. Only those whose names are written in the Lamb’s Book of Life will enter the Kingdom of Heaven.
“But as it is written, Eye hath not seen, nor ear heard, neither have entered into the heart of man, the things which God hath prepared for them that love him” (1 Cor. 2:9).