our solar system

 

8 planets of our solar system + asteroid belt (they don't count Pluto as a planet anymore).  Starting from the Sun, the 4 minor planets: Mercury, Venus, Earth, and Mars, then the main asteroid belt, which consists mostly of asteroids made of stone, iron, nickel, and other ores.  The Main Asteroid Belt is followed by the 4 major planets: Jupiter, Saturn, Uranus and Neptune, followed by The Copper Belt, which consists mostly of icy objects, dwarf planets (including Pluto), dust and comets.  Kuiper Belt objects are called KBO's.  Then there's the Oort Cloud, which consists of billions of icy chunks of space debris stretching to the edge of the Solar System.  Sometimes objects are ejected from the Oort cloud and fall toward the Sun, becoming comets.  Asteroid belts are not as impenetrable as they seem.  Objects in the main asteroid belt are on average 600,000 miles across.  Probes such as Voyager 1 and 2, Pioneer, and others have successfully passed through these belts, and NASA's New Horizons specifically visited the Kepler belt by flying past and photographing Pluto.  Five active probes currently have enough speed to escape our solar system.  Voyager 1 made its transition into interstellar space in 2012.  As of 2019, Voyager 1, Voyager 2 and Pioneer 10 are the only probes that have actually reached interstellar space.  The other two are on interstellar trajectories.