I immediately thought of Terra. Randolph Mantooth did tell TOS Apollo that that world was sometimes called Earth. TOS Galactica stopped their world war by blowing the Eastern Alliance missiles out of the sky. But suppose they werent there to stop it this time, and the two sides annilated each other? Could still be our Earth of course. Nevertheless, there are possibilities. And Starbucks disappearence is still unexplained. Her ship apparently destroyed, a brand new one apparently constructed to duplicate it. It and only it can pick up this "colonial signal" (signals which our Earth does not, and would not use). Certainly a nuked civilization didnt save Starbuck, build a new viper or send signals that only one ship could pick up.