When the stars move from one age to another by the precession through the equinoxes, the new constellation was said anciently to be a new earth.1 There is a different constellation that appears at sunrise on the vernal equinox, and that constellation tells you what age (Pisces, Aquarius, etc.) mankind is in. When that constellation changes from the previous constellation age (on the horizon at the vernal equinox), that’s called a New Earth. There will be a New Heaven and a New Earth when Christ returns.2
1 “Signs of the Second Coming, “April 7, 2016, blog post.
2 500th Year Reformation Talk Three, 16, Atlanta, GA, Nov. 16, 2017, Q&A.