* The edge of the planets: If you measure the distance between the farthest planet (Neptune) and the closest planet (Mercury), the solar system is about 28 astronomical units (AU) wide. 1 AU is the average distance between the Earth and the Sun.
* The Kuiper Belt: This region beyond Neptune is home to icy bodies like Pluto and Eris. The Kuiper Belt extends out to around 50 AU.
* The Oort Cloud: This hypothetical sphere surrounding the solar system is thought to hold trillions of icy objects and is believed to be the source of comets. The Oort Cloud's inner edge is estimated to be around 10,000 AU from the Sun, extending potentially as far as 100,000 AU.
* The heliopause: This is the boundary where the Sun's influence ends and interstellar space begins. It's thought to be about 120 AU from the Sun, though its exact location is still being studied.
Therefore, depending on how you define the edges of the solar system, its width can vary from 28 AU to 100,000 AU or even further.
