I've reached the point where I've rescued a Reticulan ship, detected the second Wargot ship (but has yet to confront it), fought a battle in my Laputa against cultist converts, and had one of my provinces yellowed by the Starghosts. And it's been months since anything happened since then. In the mean time, I've conquered nearly the entire world (only South America left), and researched all of the available technologies, but still nothing happened. One thing that might be indicative of the problem is that when I got my first province turned yellowed, I got the cutscene with the staff telling me that "the enemy has changed their tactics" or some such, but no one has yet to mention anything about Starghosts, even though I've fought a dozen defense mission with them since then. Similarly, I've been unable to research anything related to the Starghosts, such as autopsy.

What am I missing?

Why the hell doesn't anyone search out before making a new thread? here is your bloody solution