The biggest planet in the Solar System is Jupiter. But the title for the second biggest planet in our Solar System goes to Saturn.
Just for a comparison, Jupiter measures 142,984 km across its equator. Saturn for comparison is only 120,536. So Jupiter is only 1.18 times as big of Saturn. Saturn is big, but it has a much lower mass. Once again, Jupiter is 3.34 times as massive as Saturn.
Since Saturn is so big, but has so little mass, it has a very low density. In fact, if you had a pool big enough, Saturn would float. The density of Saturn is less than water. And this means that you wouldn’t experience a lot of gravity if you tried to walk on the “surface of Saturn”. If you were standing on the surface of Saturn (I know, that’s impossible), you would experience only 91% the force of Earth’s gravity.
If you wanted to compare Saturn to Earth, it’s 9.4 times as big as the Earth, and 95 times as massive. It it was just a hollow shell, you could pack 763 Earths inside Saturn, with a little room to spare.
Wanna see Jupiter? Here are amazing telescopes from Amazon.com which you can buy at reasonable prices:
We have recorded a whole series of podcasts about the Solar System at Astronomy Cast. Check them out here.