Until the twentieth century it was believed by most that the heavens were unchanging and eternal and the earth changing and new. Now we know that the bedrock beneath our feet is far older than most of the brightest stars that we can see in the heavens. An explorer with a time machine would find many of the stars during the age of the dinosaurs unrecognisable. Major changes have occurred even during the 2 or so million years of human evolution.
The Gould Belt, also called the Lindblad Ring, forms the immediate stellar neighbourhood. Even the oldest parts of the Gould Belt are less than 60 million years old, and much of it is far younger still.
More to come soon.