Gee. I'll have to guess at what's "commonly thought".
One thing is the scale. Nobody has an accurate picture of the scale in his head, because we never see a true-scale drawing. THAT's because it's almost impossible to draw one on paper.
Example: Shrink the solar system and everything in it so that the Sun is the size of a quarter (the 25¢ coin). Then: -- The Earth is in orbit around the sun, 8.6 feet from it. That's close enough that you might think you could find the shrunken Earth. Unfortunately, it's only 0.009 inch in diameter.
-- The shrunken Jupiter is a 'huge' gas giant almost 0.1 inch in diameter. It's orbiting the sun, about 45 feet away from it.
-- The shrunken Uranus is another gas giant, about 0.035 inch in diameter. It's orbiting the sun, about 165 feet away from it.
-- The nearest star outside of the solar system is 441 MILES away ! On the same shrunken scale ! And there's NOTHING between here and there !
I think that's the biggest point to make about the REAL solar system ... its utter emptiness. With the sun reduced to something you can hold in your hand, the planets are the size of grains of sand, with hundreds of feet of nothingness between them.
Same for its mass: The solar system is approximately nothing but a star. That's it. A star, with some dust and some gas around it, and here and there in the neighborhood a microscopic pebble or a chip of mineral. But mostly it's nothing but a star ... if you went around and gathered up all that other rubbish in the same bag and called it a part of the same solar system, the sun would still have more than 99% of the total mass, and the bag would hold less than 1% of it.
Book ... It's getting late, Hillary's fading, and that's all I can think of. I hope this much is some help.
