The solar system consists of the sun and objects that orbit around it. The sun is at the center and is a star. There are nine planets including Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. The inner planets are closest to the sun and include Mercury, Venus, Earth and Mars. Earth is unique among inner planets as it has water and oxygen in its atmosphere to support life. The outer planets are farther from the sun and made of gases, including Jupiter, Saturn, Uranus and Neptune. Pluto is smaller than other outer planets. Asteroids and comets also orbit the sun.
6. Inner Planets 1. Mercury 2. Venus 3. Earth 4. Mars They are the four planets closest to the sun.
7. Earth is different from the other inner planets. It has a watery surface. It is the only planet with a lot of oxygen in its atmosphere. Earth has plant life and animal life.
10. Outer Planets are made mostly of frozen gases. Their surfaces are colder than the inner planets because they are farther away from the sun. Most outer planets have many moons.
11. Pluto is different from other outer planets. It is the smallest planet in the solar system.
12. Other objects in the solar system Asteroids are chunks of rock or metal that orbit the sun. Comets are large balls of ice and dust that orbit the sun.