What is the Second Biggest Planet in the Solar System?
Written by Fraser Cain
The biggest planet in the Solar System is Jupiter. But the title for the second biggest planet in the 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.
Here's the article about how Jupiter is the biggest planet in the Solar System. And here's another article about just how big planets can get.
Here's more information about Saturn from NASA's World Book, and another page on Saturn from NASA's Solar System Exploration Guide.
We have recorded a whole series of podcasts about the Solar System at Astronomy Cast. Check them out here.
Filed under: Astronomy
