Stars and Brightness — Answer Key
Part A: Fix the Sentence
Each sentence has an error. Rewrite it correctly on the line.
1. Fix the sentence:
The Sun is a planet that gives Earth light and heat.
Corrected: The Sun is a star that gives Earth light and heat.
The Sun makes its own light through nuclear reactions, so scientists classify it as a star, not a planet.
2. Fix the sentence:
We cannot see stars during the day because they turn off.
Corrected: We cannot see stars during the day because the Sun's light is too bright.
Stars never stop shining. Sunlight scatters in our sky and overpowers their faint light each day.
3. Fix the sentence:
The Sun moves around Earth, which is why we have day and night.
Corrected: Earth rotates on its axis, which is why we have day and night.
Earth spins once every twenty-four hours, so different sides face the Sun, creating day and night.
Part B: Fill in the Blank
Write the missing word or number on each line.
1. The closest star to Earth is the Sun.
The Sun is about 93 million miles away, far closer than any other star we can see.
2. Stars look like tiny points of light in the night sky.
Stars emit light from hot gas, but distance makes them appear as small twinkling dots.
3. Earth's rotation on its axis causes day and night.
Earth completes one rotation every twenty-four hours, swapping which side faces the bright Sun.
4. We cannot see most stars in the daytime because the Sun is too bright.
Sunlight scattered through our atmosphere outshines distant stars, hiding them from our eyes.
Part C: Short Answer
Answer each question in one or two complete sentences.
1. Why is the Sun important for life on Earth?
Sample answer: The Sun gives Earth light and heat, which plants need to grow and animals need to stay warm and survive.
Without the Sun's energy, Earth would be dark, frozen, and unable to support most living things.
2. Why do stars appear so small from Earth?
Sample answer: Stars appear small because they are extremely far away, even though they are actually huge balls of hot, glowing gas.
Distance makes large objects look small. Stars are trillions of miles away, so they shrink to dots.