The Sun: Our star Pluto Mercury Neptune Venus Uranus Earth Sun Saturn Mars Jupiter •The sun is very hot. •The sun provides energy that heats the Earth and allows plants and animals to survive. •The sun is very bright. •Light from the sun allows animals to see and plants to make food. •The Sun has a strong force of gravity. •The Sun’s gravity holds Earth close to the Sun where it received the Sun’s energy. •The Sun is a good distance from the Earth. The Sun is far enough away that the Earth is not too hot or too cold. Our Sun is the closest star to the Earth. It is at least 4.5 billion years old. Without the Sun, the Earth would not be able to support life. THE SUN •Surface temperature is 5500 o C •Interior temperature, 15,000,000 o C The Sun’s diameter is 1,380,000 km •110 X Earth’s diameter •The Sun’s mass is 745 X > than all planets •The Sun’s volume equals 1 million Earths The Sun’s Structure • The Sun’s corona, or atmosphere, is only visible during an eclipse. • The photosphere has a grainy look. Its surface is made up of hot, bright areas called granules. The Sun’s Structure • A sunspot is a dark area on the photosphere. • Sunspots appear dark because they are cooler than the rest of the Sun. • The sunspot theory suggests that these areas are formed due to changes in the Sun’s magnetic field.