The Solar System
作者：no way
1. Sun
1.1. a star
1.2. source of energy
1.3. very hot
1.4. mostly hydrogen
2. Asteroids
2.1. some are considered dwarf planets
3. Planets
3.1. Inner Planets
3.1.1. Mercury
3.1.2. Venus
3.1.3. Earth
3.1.3.1. Our planet
3.1.3.1.1. supports life
3.1.3.1.2. rocky surface partly covered in water
3.1.3.1.3. atmosphere of nitrogen and oxygen
3.1.3.1.4. energy from the sun keeps us warm
3.1.4. Mars
3.2. Outer Planets
3.2.1. Jupiter
3.2.2. Saturn
3.2.3. Uranus
3.2.4. Neptune
3.2.5. Pluto ?
3.2.5.1. Now considered a dwarf planet