New sky and a new planet?

As many times as I have read the book of Revelation in the Bible, I don't know if I have ever really stopped to think much about the first verse of chapter 21. I think I've always just assumed the passage was meant in a spiritual or figurative sense. But yesterday the possibility that it might be suggestive of something physical popped into my mind. Here is what the passage says:

Then I saw “a new heaven and a new earth,” for the first heaven and the first earth had passed away, and there was no longer any sea. -Revelation 21:1

The word 'heaven' means 'sky'. We typically think of Heaven as being the spiritual dwelling place of God -- and I am not suggesting that it isn't -- I'm merely pointing out that when the term 'heaven' is used in that context, the notion is the spiritual dwelling place of God is 'out there' somewhere in the sky. So what exactly is this "new heaven" and "new earth" mentioned in Revelation? It's actually not the only time that is mentioned in the Bible. It is also mentioned in the Old Testament book of Isaiah.

See, I will create
new heavens and a new earth.
The former things will not be remembered,
nor will they come to mind. -Isaiah 65:17

So are these passages suggesting that a new sky and a new earth (new planet) are in humanity's future? In this sense, the sky may more literally refer to the visible constellations and the movement of the stars. But if you were on another planet, the constellations would appear differently. So could that be what is meant by a new sky, or "new heaven?" If so, is this a prediction that humanity will one day move to a different planet, or a "new earth?" The passage in Revelation also says there was no longer any sea, so could that mean that the new planet is quite literally a newly formed planet that a sea hasn't even formed on yet?

I'm not really sure. It's difficult to tell if the passage is meant to be taken figuratively or literally. Is it suggesting that humanity will one day travel to another world on a spaceship? Or is it just saying that humanity will one day travel to a new world in spirit? Going there in spirit would probably be more in line with traditional interpretations. In verse 2 of Revelation 21, John says he saw the Holy City, the new Jerusalem, coming down out of heaven from God. To the ancient alien enthusiast, this probably sounds like a spaceship landing. But I'm not so sure about that. The passage could very well be meant in a spiritual or figurative sense. To me, most of the rest of the chapter seems to be more indicative of something figurative or spiritual. In fact, in verse 10, John even says than an angel carried him away in "Spirit" to see the Holy City coming down out of heaven from God.

John goes on the describe what the city looks like. An ancient alien enthusiast might say he was describing some sort of spacecraft in terms he was familiar with. But it really doesn't sound like that to me. The description really just sounds like the description of a beautiful ancient walled city with enormous wealth.

So what is this passage really saying? Is it humanity's destiny to one day travel through space and settle a new world? Or is just saying that humanity's destiny is to travel to a new world in spirit one day? Judging by the chapter as a whole, I think it probably means in spirit. But hopefully one day it's meaning will become clear to us definitively.  We may just have to wait and see what happens.  :)

You can read the whole chapter here: Revelation 21

You can read the whole book here: Book of Revelation