The creation story - a 6000-year-old earth Or the aftermath of a comet impact?

The creation myth came into existence because people didn't know how the world was created, so they made up a story about how God did it.
The flood myth may have been the account of a local flood sometimes in the past, that later grew into a story about a global flood.

I think this is much more realistic than a comet impact and global flood that left no evidence behind.