I've found that no matter how large a galaxy I play with, the anomalies are all gone after the first year or two. Long before I've reached a point where I can upgrade my survey ship, making the experience upgrades completely useless, and long, LONG before the 'Galactic Guide Book' achievement can be built. Is there any sort of option to have anomalies spawn randomly as the game progresses to give my survey ship something to do after the second year?