Defining a GenreExperience often complicates things or, at least, reveals more details and complexity than you saw at the beginning. Any Science Fiction author with a book or two behind them will tell you that there is a LOT more to it than that. First of all Sci Fi has a plethora of sub-genres, including Space Opera, Hard Sci Fi, Military Sci Fi, Steam Punk (and a range of other "Punks"), Apocalyptic,Post-apocalyptic, Time Travel, Dystopian and many, many more.
Some groups have made serious efforts to formalise the definitions of each of these, but most authors I've spoken too rarely find that their work falls into a single genre. Some authors manage to pick a key genre and a couple of sub-genres but others, like me, find their output really spans about half-a-dozen genres and various from book to book. This makes it extremely difficult for readers to categorise me.
Now I fully realise the importance of tying your work down to a genre as it makes it easier to market, easier to categorise when submitting it for reviews and book directories, and much easier when you come to talk to agents about it. They tend to prefer a clear cut genre for your work so they know how to pitch it and who to pitch it to. Your children's science fiction vampire romance book is going to be hard to sell no matter how good it is, as publishers won't know what to do with it.
How Do I Categorise My Own Books?Astronomicon: The Beginning) was basically classic sci-fi in style. The protagonists were sent to colonise a planet around another star system, things go wrong and they end up fighting to survive in a hostile environment. However this forms the introduction to a much bigger story of human development, politics, technology, space exploration and ultimately war. This now crosses into Space Opera territory.
The second half of the book strays much more into the politics behind the events of the first half, revealing the civil unrest in the mining colonies on Jupiter's moons and sweeping political changes back on Earth. Military action around Jupiter and an assassination on Earth show that there are much greater problems brewing for the human race as a whole. A hefty part of this could easily be categorised as Military Sci Fi.
Astronomicon: Distant Relatives) is more of an action thriller set within a science fiction setting. A first contact situation opens the story, but surprisingly that is soon overtaken by events of a more local nature. Again the story explores some of the politics involved, but also covers events back on the colony from the first book where a mini-war has broken out.
I find it a little depressing that some reviews have referred to this book as a bridging piece between the first book and the ongoing storylines. That was not intended, and the book features a ranges of large-scale key events in the on going story. It is most certainly not a space filler, but I suppose being a bridge is necessary factor in not being the first or last book in a series. That doesn't stop it being an exciting and vital bridge.
Astronomicon: Those Left Behind) is in many ways a different creature again. It mainly covers the lives of two characters: The ruler of an alien race desperately trying to salvage something in the face of imminent annihilation of his species, and an office worker striving to save the lives of his two children during an alien invasion.
This splits it equally between Military Sci Fi and Apocalyptic Sci Fi. Of course it still fits in with the ongoing Astronomicon storyline, so it's also Space Opera. Which is the main genre? I genuinely don't know.