[carlos_dfc]

Hi Bombus (x2)

Miles are too small an increment to use when thinking of something the size of the Solar System. The AU (Astronomical Unit) is a much better measuring stick.
An AU is the average distance from the Earth to the Sun - about 93 million miles, or 150 million km.
A light-year is about 6,240 AUs

Pluto's distance from the Sun varies between about 29.5 AU, and 50 AU - which puts it smack in the realm of the Kuiper belt.
The Kuiper belt is similar to the Asteroid belt, except that it stretches from around Neptune's orbit (30 AU) out to about 55 AU - and Kuiper belt objects (KBOs) are mainly icy, whereas the ateroids are mainly rocky.
Pluto is basically a large KBO (and it isn't even the biggest one) - When Pluto was discovered, nobody knew there was such a thing as the Kuiper belt - so it was wrongly designated as a planet - If it had been discovered recently, it would straight away have been designated 'KBO'

The Oort cloud is a sphere of mainly icy material which streches roughly from the edge of the Kuiper belt (55 AU), out to a distance of about 50,000 AU (about 5/6 of a light-year)

So - the bulk of the solar system (Sun, planets, asteroids, and Kuiper belt) only stretches out to about 1/1000th of a light-year (0.1%) with only the Oort cloud going out further.

As an idea of scale.....
If the Sun was the size of a tennis ball, then if you took 5 tennis balls, and spread them randomly inside a sphere the size of the Earth - you'd have a good approximation of the density of stars in our part of the galaxy.