Actually, our solar system is MOSTLY space, with only a tiny percentage of its volume taken up by matter like the sun, planets, and asteroids. The solar system is flying through space at around 490,000 mph as it orbits the center of the Milky Way galaxy (27,000 light-years; or 162,000,000,000,000,000 miles away). Our solar system will probably be stuck in orbit around the center of the galaxy forever, due to the enormous gravity of the galaxy. So, we don't have to worry about being flung into intergalactic space any time soon!