In Catholicism - given our Augustinian amillenialism - the Second Coming of Christ is synonymous for us with the final judgement, the dissolution of the universe and the creation of a "new heaven and earth" (i.e. the "life of the world to come" referred to in the Nicene Creed)....................................
I agree there will be a ' final judgement ' at the soon coming ' time of separation ' on Earth as found at Matthew 25:31-33,37,40.
A favorable judgement on Earth for the figurative humble ' sheep' but an adverse judgement for the figurative haughty ' goats' .
Since the Earth abides forever - Ecclesiastes 1:4 B; Psalms 96:10; Psalms 104:5; 1 Chronicles 16:30; Isaiah 45:18 - there is No expiration date for Earth.
The ' NEW Heavens and Earth ' is in connection to a NEW heavenly government or kingdom over Earth for a thousand years.
The NEW Earth is Not a new planet but NEW in the sense that the Earth remains forever will become as described in Isaiah 35th chapter.