First Contact Science Fiction Books

Science Fiction that details the initial meeting between humans and an alien species. The meeting can be benign or hostile.

Alien Invasion Books

A straightforward classic science fiction sub-genre about aliens invading human territories -- usually Earth. The settings usually take place in a Near-Future or Present day period, though some Alien Invasion tales involve mankind reaching out to the stars and suddenly encountering aliens as they explore.

Alien Conspiracy Science Fiction Books

Science Fiction about the existence of alien life and any sort of interaction with extraterrestrials has been covered up.