The Rings of Saturn

Galileo noticed these rings, although he couldn’t quite see what they were. Since they are thousands of miles across and only 20 meters thick, they are much relatively thinner than paper (and you can see through them. They are composed of billions of tiny bodies, from dust to boulder sized. We now think that rings only last for millions of years, so we are privileged to see them so nice. [Maybe 50 million years from now, Mars will be better.]