2. Our Solar System

3. The Sun In ancient times, some people thought of the Sun as a god. They did not want the god to be angry with them. To keep the Sun happy, they offered it gifts such as food and gold. The Sun has small storms, called ‘’sunspots,’’ that are so called that they look spot-shaped when astronauts look-well, at least not directly- at it.

4. Mercury Mercury is the second-smallest planet: Only the planet of Pluto is smaller. The average distance from the Sun is 36 million miles. The hottest temperature on Mercury is 870 degrees Fahrenheit, while the coldest is –300 degrees Fahrenheit.

5. Venus The clouds on Venus are made of sulfuric acid. The usual temperature on Venus is 900 degrees Fahrenheit. The average distance from the Sun from Venus is 67 million miles. Venus does not have any known moons, just as Mercury does not have any.

6. Earth 97% of the water on Earth is salt water in oceans. Usually the temperature on Earth is 45 degrees Fahrenheit. The average distance from the Sun on Earth is 93 million miles.

7. Earth’s Moon The Moon travels around the Earth in an oval shaped orbit. Some scientists think that Earth’s moon may have been formed from a collision between Earth and another space object.

8. Mars The average distance from the sun on Mars is 142 million miles. The hottest temperature on Mars is 90 degrees Fahrenheit, while the coldest is –190 degrees Fahrenheit. Mars has 2 moons, and the reddish color on Mars is caused by rust from soil.

9. Jupiter The average temperature on Jupiter is –244 degrees Fahrenheit. The average distance from the Sun on Jupiter is 483 million miles. The Great Red Spot on Jupiter can fit 2 Earths inside! Jupiter has 17 known moons.

10. Saturn The average distance from the Sun on Saturn is 888 million miles. The average temperature on Saturn is usually –300 degrees Fahrenheit. The rings around Saturn are made of rock and ice particles. Saturn has 18 known moons.

11. Uranus The temperature on Uranus is usually -350 degrees Fahrenheit. The average distance from the Sun on Uranus is 1,784 million miles. Uranus’s blue-green color comes from methane. Uranus has 15 known moons.

12. Neptune The average temperature on Neptune is usually –370 degrees Fahrenheit. The average distance from the Sun on Neptune is 2,794 million miles. Neptune had a Great Dark Spot once like Jupiter’s Great Red Spot. Neptune has 8 known moons.

13. Pluto The average distance from the Sun on Pluto is 3,647 million miles. The average temperature on Pluto is usually –390 degrees Fahrenheit. Pluto has 1 known moon, known as Charon, and its surface has dark markings.