LAST JUNE, THE LONG AWAITED SEQUEL INDEPENDENCE Day: Resurgence opened in theaters around the world. Although not as commercially successful as its blockbuster predecessor, the film at least elaborated in greater detail on alien motivations for conquering Earth. As explained in the story, the alien mothership sought to harvest the heat of the Earth’s core, which in the process would destroy the planet’s magnetic field, thus obliterating all of its inhabitants. Such a scenario is highly improbable because there would be more feasible methods for alien civilizations to extract comparatively greater amounts of energy, including harnessing the heat of stars, which are estimated to number 400 billion in the Milky Way Galaxy alone.1 Moreover, it does not seem plausible that an advanced alien civilization capable of traversing interstellar distances would be interested in extracting the relatively crude energy sources or harvesting resources to be found on Earth when such commodities could be obtained in much greater quantities closer to the home planet. From the perspective of an advanced alien civilization, plundering the Earth for its resources would be neither practical nor desirable. Be that as it may, there would be good reasons for interstellar colonization, primarily for defensive, rather than offensive purposes. To ensure its longterm survival, a civilization would need to keep apprised of what is happening outside of its star system, for there are a number of perils that lurk in the Galaxy. Thus, the construction of a Galactic Defense System is advisable.
Illustration by Ástor Alexander
Perils in the Galaxy