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During the 30 years of exodus, a few changes have befallen Adama and the Fleet. Apollo has apparently died, although his step-son Troy is a captain in the Fleet and becomes a key figure (along with Lieutenant Dillon) in many of the missions to Earth. Adama's right hand man, Colonel Tigh, has been replaced by Colonel Boomer.
The finding of Earth does not prove to be the salvation that the Colonials had hoped for, however, as they find Earth to be woefully behind in technology and culture.
Adama and his advisor, Doctor Zee, determine that the Earth is not yet ready for contact with Galactica or the Cylons. They decide that covert action would be more prudent, and thus begin a plan whereby they influence the people of Earth in the hopes of helping to prepare them for contact (1980: "Galactica Discovers Earth").