The structure of the solar system

 We can see the sun in the sky. Our Earth turns the sun.  Sun is very heavy. Many planets turns the sun. Sun and many objects that turns the sun called "Solar system" Solar system's center is the sun. Mercury is the closest to the sun. Venus is 2nd, Earth is 3rd, Mars is 4th, Jupiter is 5th, Saturn is 6th, Uranus is 7th, Neptune is 9th.  Mercury, Venus, Earth, Mars are rocky planet. It has a land that you can walk. Rocky planets are small and have big density.

And Jupiter, Saturn, Uranus, Neptune are called "Gas Giant" They are big and they are not rocky. They have lots of gas. So they don't have a land that you can walk. They have small density.

 

 

 

And there is no big planet over the Neptune. Astros that farther than Neptune called TNOs. Over the Neptune, there are Kuiper belt, and Oortclod. In kuiper belt there are many asteroids and dwarf planets. Pluto, Haumea, Makemake, Eris, Sedna,Quaor are dwarf planets. Oort cloud is end of the solar system. Oort cloud is origin of long period  comet. Oort cloud's end is about 50000AU from the Sun. It's our Solar system.

(Oort cloud. www.newscientist.com)