Alberth already caught most of the things I saw, but I want to give some more general advice. If you look at the movableObject class, you'll see that it only has some member variables and some setters and getters for them, but no functions that have any behavior that's unique to that class. I would expect this class to have a move() function that then updates the position using the direction (deltaX, deltaY?). Right now this is spread out and duplicated all over the place, in asteroid::moveAsteroid and the various move*** function in main.cpp.
SFML also has the sf::Vector2f type that you could use instead of splitting every position in an X and Y variable. (If it needs to be integers you can also use sf::Vector2i)
Also regarding the Sleep(10), what I recommand doing right now is enabling vsync (SFML uses OpenGL by default right?) It's more reliable than the Sleep function and has the added benefit of preventing screen-tearing. Later on you can decouple the render-loop from the simulation-loop by following the fix-your-timestep article.