2. In the margin of your paper, please write why you think stars are important? Share your ideas with a partner.

3. 1. The closest star to Earth is the Sun. It is 150 million kilometers away from Earth.

4. 2. The Sun is an average-sized star.

5. 3. Red stars and orange stars are cooler than the Sun, and blue stars and white stars are warmer.

6. 4. The Sun will glow for many more years.

7. 5. Scientists measure the distance of stars from Earth in light-years.

8. 6. Throughout the universe, stars are found in large groups called galaxies.

9. 7. Because of Earth’s orbit, we see different constellations.

10. 8. The constellations appear to move across the sky throughout the year.

11. 9. The night sky looks different in the Northern Hemisphere than it does in the Southern Hemisphere.

12. 10. Once there were no clocks, and people used constellations to tell time.

13. 11. Long ago, farmers used constellations to tell them when to plant or harvest crops.

14. 12. Sailors used constellations to steer at night.

15. 13. The Sun gives off energy in the form of light and heat.

16. 14. The Sun provides the energy needed by almost all of Earth’s living things.

17. 15. The Sun’s energy powers winds, ocean currents, and the water cycle.

18. Do you think it is possible to get a sunburn on a cloudy day? Share your answer with a partner.

19. 16. It is possible to get a sunburn on a cloudy day. As long as it is daylight, our part of Earth is facing the Sun, and the Sun is giving off light energy as well as heat energy. Even though the clouds may block a little bit of the sunlight, our skin is still exposed.