Can any one tell me the name of a sci-fi Novel in which characters in a spaceship hunt for a 'mythical' long forgotten earth.
- they use 'rutters'/ Ancient book which contain images of symbolic forms/animals that indicate how to traverse a path through to gateways.

The Symbolic images/charts are coded stars/planets to be followed upon this journey

- Earth is a long forgotten planet, almost a forgotten myth.

- The 'Rutter' is ancient and valuable.

any help guys. I have looked for this book for years