1.Why gas planets are far from the Sun?
Rock planets are close to the sun. But gas planets are far from the Sun. Rock planets' space is hotter than gas planets' space. So in rock planets' space, many meterials are less intergrated than gas planets' space. So Jupiter, Saturn, Uranus, Neptune is bigger than Mercury, Venus, Earth, Mars.
2.How did gas planets created?
Maybe you learned that Gas planets don't have surface that you can walk. But if we go to inner of Gas planets' atmosphere, we can find a planet that have a liquid surface. Maybe liquid is created by gas' pressure. Liquid was maybe a gas. Maybe Jupiter,Saturn,Uranus,Neptune were rock planets. But because of their strong gravity, they have very big atmosphere. And it would became gas planets.
Sorry, everyone. I became a middle school student. I was so busy and I can't posted about cosmos. Today, I have a enough time. I will post about Asteroid belt's creation process.
These are planet's semi-major axis.
Mercury:0.4AU
Venus:0.7AU
Earth:1.0AU
Mars:1.6AU
Jupiter:5.2AU
Saturn:10AU
Uranus:19.6AU
Let's multiply 10
Mercury:4
Venus:7
Earth:10
Mars:16
Jupiter:52
Saturn:100
Uranus:196
Let's subtract 4
Mercury:0
Venus:3
Earth:6
Mars:12
Jupiter:48
Saturn:96
Uranus:192
You can find a rule. But there is a problem. There is no planet that have 24.
Celestial body that have 24 is not a planet, but asteroid belt. You can have a doubt. Why there is no planet at 2.8AU? Why most of asteroids are in the belt? Astronomers deduce that there was a planet. But the planet is split by Jupiter's gravity. So many pieces of the planet became Asteroid belt. But this planet was very small. It is smaller and ligter than moon
