I was curious about a couple things and did a little surfing…
Diameter of our solar system. First know that they use Astronomical Units (AU). One AU is equal the mean distance from the center of the earth to the center of the sun or 150 million kilometers, or about 92 million miles. The diameter of the solar system is between 60 AU and 180 AU depending upon how you define it. ref
Milky Way ~ 100,000 light years in diameter, 200 – 400 billion stars. ref
Nearest star: Alpha Centauri ~ 4 light years away. ref
1 light year is about 5.8 trillion miles. ref
Nearest galaxy: Cannis Major Dwarf – Actually it’s sort of part of the Milky Way only 25k-40k light years away from Sun – apparently it collided with Milky Way long ago. Only has a billion stars. ref
A few other galaxies are similarly close < 100k light years away.
Andromeda Galaxy 2 million light years away nearest spiral galaxy, is bound to Milky Way, this plus Milky Way plus a few other galaxies make up the Local Group which are gravitationally bound together.
The Large and Small Magellanic Clouds are two irregular dwarf galaxies about 180,000 and 210,000 light-years away, respectively. They were thought to be orbiting the Milky Way, but that may not be the case..
All of these galaxies make up part of what is called the Local Group, which is a group of more than 30 galaxies that lie within 4 million light years of the Milky Way. Here’s a great article from the Spitzer Space Telescope’s website on the Milky Way’s family of close galaxies and a video by the same author on the subject. Read more:ref
All the stars we can see with the naked eye are within 1000 light years away, so they’re all in our Milky Way. ref
There are a few galaxies we can see with the naked eye;
The Andromeda Galaxy is 2.5 million light years away, but is visible in the night sky in the Andromeda constellation as a hazy patch of light about the size of the full moon. The Large Magellanic Cloud and the Small Magellanic Cloud are 2 smaller satellite galaxies of our own Milky Way, and are visible in the southern hemisphere. ref