Interstellar Objects
The vast majority of space is empty. However, gravitationally clusters of objects can form. For instance, the main asteroid and Keiper belts are clusters of objects that orbit the inner and outer solar system respectively. The objects that exist within these belts range from small microscopic ices to large macroscopic chunks. Due to its size and mass, everything contained within our solar system is gravitationally bound to the sun. The gravitational field associated with small or large object interact with the sun to form a stable circular orbit. In accordance with Newtonian mechanics this effect is more prominent with larger planetary objects then that of smaller particle sized objects. This gravitational attraction from the sun is large, but not infinite. At distances of up to 3.2 light years from the sun the gravitational bind is no longer felt. At these distances a final layer of objects are located and surround our star. This is called the Oort cloud: Much like Earth, the Oort cl...