2. The Solar System Science Third Grade

3. The solar system is the sun and the objects that orbit around it.

4. The sun is the center of the solar system. It is a star.

5. Planets A planet is a large body of rock or gas that orbits the sun. The solar system has nine planets, including Earth.

6. Planets MercuryVenusEarth MarsJupiterSaturn UranusNeptunePluto

7. Inner Planets 1. Mercury 2. Venus 3. Earth 4. Mars They are the four planets closest to the sun.

8. Inner Planets They all have rocky surfaces, and they are warmer than the outer planets.

9. 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. Earth

11. Outer Planets 1. Jupiter 2. Saturn 3. Uranus 4. Neptune 5. Pluto

12. 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.

13. Pluto is different from other outer planets. It is the smallest planet in the solar system.

14. 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.