30 “They shall perish, but You shall endure”. The Apostle Peter says this openly: “By the word of God the heavens were of old,” etc. He has said then that the heavens have already perished by the flood: and we know that the heavens perished as far as the extent of this atmosphere of ours. For the water increased, and filled the whole of that space in which birds fly; thus perished the heavens that are near the earth; those heavens which are meant when we speak of the birds of heaven. But there are heavens of heavens higher than these in the firmament: but whether these also shall perish by fire, or those only which perished also by the flood, is a much harder question among the learned, nor can it easily, especially in a limited space of time, be explained. Let us therefore dismiss or put it off; nevertheless, let us know that these things perish, and that God endures....
Source: The Enarrations, or Expositions, on the Psalms (New Advent)