Unit D: Weather and the Sky
1. Get Set to Explore
- star: An object in space that makes its own light.
- the Sun: The star closest to Earth.
- Review the vocabulary words with the class. Have children look out the window of the classroom around midday. Ask them to name space objects they can see in the sky. Write their answers on the board in a two–column chart. Label the column where you write their answers “Space objects we can see in the sky during the day.” On a clear day, you will be able to see the Sun; you may also be able to see the Moon.
- Ask children to name space objects they can see in the sky at night. Write their answers in the other half of the chart on the board, labeling this half “Space objects we can see in the sky at night.” On a clear night, children should be able to see stars. They may also be able to see the Moon, planets (which look like bright stars to the naked eye), orbiting satellites, and the Milky Way (part of our galaxy, which appears as a hazy band stretching across the central part of the sky). Shooting stars, which are meteorites, are commonly seen at certain times of the year; occasionally comets can be seen in the night sky and, if they are extremely bright, even in the day sky.
- Elicit definitions of day and night from the class. Remind children that day changes to night and back into day again because Earth is spinning, or rotating. Refer to children's experiences with models of how and why day changes to night. One example is the Investigate activity on Student Edition page D51. Encourage children to ask questions.
- Introduce the Discover! question: Where are stars during the day? Let children predict the answer and write their predictions on the board.
2. Guide the Exploration
- Direct children to launch the Discover! Simulation and to listen closely to the question and the directions.
- Children should spend some time watching the sky change from night to day and back to night, while listening to the narration. Point out that the clock in the lower left corner of the screen shows the time depicted on the screen. Tell children that they can click Show Stars in the upper right corner to see the stars during the daytime.
- When children finish viewing the simulation, return to the predictions they made to answer the Discover! question. Let them revise their predictions if they wish.
- Then, review Step 3's Wrap-Up text. Remind children that the simulation had a feature they could click Show Stars which showed the stars that would be visible in the daytime sky, if the sky were dark enough. Encourage children who didn't use that feature, to go back and try it.
- Ask children: What prevents us from seeing stars in the sky during the day? Guide them to understand that the light from the Sun makes the sky quite bright, preventing us from seeing starlight. Stars become visible as the sky darkens at or after sunset.
- Use the Extension questions to reinforce children's understanding of the main
concept. Ask: When can you see the stars? When does it become too difficult to
see the stars? Have children repeat the simulation, if necessary.
- The stars are clearly visible at night.
- It becomes difficult to see the stars about one-half hour before sunrise; the stars become visible again about one-half hour after sunset.
If time permits, present children with the following question or activity:
- Inquiry Skill Record and Interpret Data Watch the sky for a week. Start watching shortly before sunset. What time is it when you first can see a star? Write down the time and the date. What pattern do you see? Answer: Children will probably be able to see their first star right around the time that the Sun sets.
- Critical Thinking Analyze Why can we see the Moon? Answer: We can see the Moon because sunlight shines on it. We see the lit-up part of the Moon.
4. Reaching All Learners
On-Level: Logical Learners
Write different times of day and night on index cards. Shuffle the cards and ask children to put the cards in order, starting with midnight. Have children arrange their cards in a horizontal timeline. After children have viewed the simulation, play a game with them in which you name a time of the day or night. Children can locate this spot on their timeline and tell you whether or not stars would be visible in the sky in the simulation; if you name a time during the day, ask children to tell you where the Sun would appear in the sky.