GunBuster The Movie

[Senkusha]

So, the other day, I watched GunBuster, the movie.  It's a pretty interesting anime, and I've always enjoyed the OP theme song.  But just what was it that Humanity was fighting? ... other than some grotesque space-slime creatures, and did we really have to vaporize the center of the Milky Way to kill these things?  At least, they had the laws of temporal physics right with relation of speed vs time.  But, I have a hard time believing that Humankind would still be on Earth in the year 14,000.... just saying.