I'm working on the following premise: outer space, or at least our solar system, is littered with creatures akin to "sea monsters". Is it possible/plausible for a creature to evolve in such a way as to have as its natural habitat outer space?
Obviously, it wouldn't be anything like life as we know it, but I don't see a reason why alien life should be in any way related to how we know it.
What would be some of the parameters/determinants of evoluiton here? Would there be a difference between the ones living around (and just maybe, on) Venus and the ones around Mars? Would the creatures need to eat or just absorb energy from sunlight? How big would they grow and why - would they get big enough to cause gravitational trouble when they move around? (Imagine one as big as a planet freely moving around the solar system, would that be safe?) How would they propel themselves/move? Flap a pair of wings? What if they were snakelike?
I'm working on a short story with this premise, and I don't intend to go deep into the mechanics of things; if it's implausible or impossible I'll just pretend otherwise. However, some of these answers may help me better present the notion and make it more consistent. Is there some similar idea developed elsewhere? Thanks.