Name Lesson 1 Summary Use with pp. 423–427 Lesson 1: What are some patterns that repeat every day? Vocabulary star a giant ball of hot, glowing gases axis the imaginary line around which Earth spins rotation one complete spin on an axis The Sun Shadows Did you know the Sun is a star? A star Have you ever sat in the shade of a tree? is a giant ball of hot, glowing gases. It is Did you know that you were sitting in a the main source of light and heat for Earth. shadow? Three things are needed to see a Earth does not glow or make its own light. shadow: light, an object to block the light, and It is also much smaller than the Sun. The a surface on which the shadow can form. half of Earth’s surface facing the Sun is A shadow forms when light hits an lit by sunlight. The half of Earth’s surface object. The object stops this light. The facing away from the Sun is dark. shadow is an area behind the object that is not getting direct light. The shadow has Day and Night about the same shape as the object that Earth is moving all the time. One way blocks the light. that Earth moves is by spinning around, or The size and shape of shadows change rotating. Earth spins on its axis. An axis during the day. Shadows are long in the is an imaginary line. One end of the line early morning hours. They stretch in the sticks out of Earth at the North Pole. The opposite direction of the Sun. This means other end of the line sticks out of Earth at shadows stretch toward the west. At noon, the South Pole. the Sun is at its highest point in the sky. Earth spins in a complete circle every Shadows are very short. Shadows become 24 hours. This is called rotation. Half long again as the afternoon passes. Now, of Earth always faces the Sun. That half the shadows stretch toward the east. This of Earth has day. The half of Earth that is in the opposite direction of the setting is not facing the Sun has night. As Earth Sun. Once the Sun sets, there is no more spins, the part of Earth that is in darkness sunlight to make shadows. slowly gets more sunlight. A new day © Pearson Education, Inc. 3 begins. At the same time, the part of Earth that was lit by sunlight slowly becomes darker. Daytime ends. This is a pattern that happens every day. 96 Chapter 15, Lesson 1 Summary Quick Study
Name Lesson 1 Checkpoint Use with pp. 423–427 Lesson 1 Checkpoint 1. What star is the source of light on Earth? 2. Sequence Describe a pattern on Earth that happens every day. 3. What is Earth’s axis? 4. Explain how each place on Earth has a beginning and an end to daytime. 5. What three things are needed to have a shadow? 6. Sequence Describe the pattern of shadows from sunrise to sunset. Include the length and direction of the shadows. © Pearson Education, Inc. 3 Quick Study Chapter 15, Lesson 1 Checkpoint 97
Name Lesson 2 Summary Use with pp. 428–431 Lesson 2: What patterns repeat every year? Vocabulary revolution one complete trip around the Sun Earth Moves Around the Sun • In March, both halves of Earth get You know that Earth rotates on its axis about the same amount of sunlight. as it revolves around the Sun. The axis is The northern half is getting warmer an imaginary tilted line through Earth. A while the southern half is getting cooler. revolution is one complete trip around Seasons the Sun. One revolution takes one year. Earth’s tilt and movement cause the Look at Earth’s positions on pages amount of sunlight and the temperature 428–429 in your textbook. Earth’s tilted to change throughout the year. Usually, axis always points in the same direction as temperatures are warmest during the Earth revolves around the Sun. But different summer and coolest during the winter. parts of Earth tilt toward or away from the In December, the northern half of Earth Sun. As a result, temperature changes occur is titled away from the Sun. It is winter in throughout the year: the northern half of Earth. • In June, the northern half of Earth tilts In March and September, Earth’s axis more toward the Sun. The northern does not point toward the Sun or away half receives more direct sunlight than from the Sun. Temperatures are usually the southern half. The northern half of warmer than in winter but cooler than in Earth is warmer than the southern half. summer. Spring and fall happen during It is summer in the northern half and these times of the year. winter in the southern half of Earth. In June, the northern half of Earth tilts • In September, no part of Earth points more toward the Sun. It is summer in the toward or away from the Sun. The northern half of Earth. northern half of Earth is becoming The Earth’s tilt also affects how we see cooler while the southern half is the Sun. The Sun is in different places becoming warmer. in the sky during different seasons. In • In December, the northern half of Earth summer, the Sun is higher in the sky. In tilts away from the Sun. It receives less winter, the Sun is lower in the sky. direct sunlight than the southern half. The northern half of Earth is now colder © Pearson Education, Inc. 3 than the southern half. It is winter in the north and summer in the southern half of the Earth. 98 Chapter 15, Lesson 2 Summary Quick Study
Name Lesson 2 Checkpoint Use with pp. 428–431 Lesson 2 Checkpoint 1. What does Earth revolve around? 2. Sequence Describe the pattern of temperature changes during the year in the northern half of Earth. Why does this happen? 3. How does Earth’s position and movement cause seasons? 4. What causes summer to be warmer than winter? © Pearson Education, Inc. 3 Quick Study Chapter 15, Lesson 2 Checkpoint 99
Name Lesson 3 Summary Use with pp. 432–435 Lesson 3: Why does the Moon’s shape change? Vocabulary phase each way the Moon looks from Earth lunar eclipse when Earth makes a shadow on the Moon The Moon and Earth Phases of the Moon The Moon rotates on its axis and The drawing on page 435 shows the revolves around Earth. It takes about 29 Moon in different positions. You can see Earth days to complete one revolution. The that half of the Moon is always lighted by Moon revolves around Earth while Earth the Sun. We cannot always see this half of revolves around the Sun. the Moon. The amount of the Moon that The Moon is the brightest thing in the we can see from Earth is a phase of the night sky. But it does not make light. The Moon. Sun lights the Moon. The Sun’s light shines The first phase is the New Moon. It on the moon and bounces off. Did you happens when the Moon gets between the know that we always see the same side of Sun and Earth. Then, the dark half of the the Moon? We never see the other side Moon faces Earth. The lighted half faces from Earth. away from Earth. We cannot see the Moon during this phase. The Moon and the Sun More of the lighted Moon can be seen as How the Moon looks in the sky changes the Moon revolves. We see the next phase a little bit each night. Each way the Moon of the Moon a night or two after the new looks is a phase of the Moon. The phases Moon. This is called the Crescent Moon always follow the same pattern. It takes phase. We can only see a small piece of the about four weeks to complete the entire lighted part of the Moon. pattern. The Moon looks like a half circle about a week after the New Moon. This is the First Lunar Eclipse Quarter phase. Sometimes Earth moves between the Sun Finally, we are able to see all of the and Moon. Earth blocks sunlight from the lighted part of the Moon. The Moon looks Moon and makes a shadow on the Moon. like a circle. This is called the Full Moon This is called a lunar eclipse. Earth’s phase. It happens a week after the First © Pearson Education, Inc. 3 shadow slowly moves and covers the Moon. Quarter. We see less of the Moon each night after the Full Moon phase. 100 Chapter 15, Lesson 3 Summary Quick Study
Name Lesson 3 Checkpoint Use with pp. 432–435 Lesson 3 Checkpoint 1. What are two ways the Moon moves? How do these movements affect the appearance of the Moon? 2. How much of the Moon is lighted by sunlight? 3. What position of Earth causes a lunar eclipse? 4. Sequence Describe the pattern of the phases of the Moon starting with a full Moon. © Pearson Education, Inc. 3 Quick Study Chapter 15, Lesson 3 Checkpoint 101
Name Lesson 4 Summary Use with pp. 436–439 Lesson 4: What are Star Patterns? Vocabulary telescope a tool that magnifies objects that are far away and makes them easier to see constellation a group of stars that make a pattern Stars and the Telescope Patterns of Stars Think about the sky on a clear, dark Did you ever see stars that are in groups night. You can see lots of stars. Some stars or shapes? A group of stars that makes a are bright and easy to see. Stars look small pattern is a constellation. You can see the in the sky because they are trillions of pattern if you imagine that lines are drawn miles away. But, some of these stars are between the stars. Look at the pictures on actually bigger than the Sun. Other stars page 439 in your textbook. You can see the are smaller. The stars that are the farthest constellations called the Big Dipper and the away are the hardest to see. You cannot see Little Dipper. many stars without tools to help you. People who lived a long time ago Binoculars and telescopes are tools. saw animals, people, and objects in star You can use these tools to see stars better. patterns. They made up stories about the These tools make stars that are far away constellations. They gave the constellations look bigger. You can see more stars with a names. People who lived in Greece saw a telescope than with just your eyes. constellation of a hunter. They named this Telescopes might have tubes, mirrors, constellation Orion. This name is still used and lenses. These parts collect light. This today. helps to give a bigger and clearer view The stars in a constellation look like they of objects in the sky. Scientists might use are close together. But they are really very telescopes like this. They also use other far apart. kinds of telescopes that do not collect light. We can see different patterns of stars at They collect other kinds of waves, such as different times of the year. This is because radio waves. Earth revolves around the Sun. The patterns of stars also change with Earth’s four seasons. Like the Sun, stars do not move. © Pearson Education, Inc. 3 102 Chapter 15, Lesson 4 Summary Quick Study
Name Lesson 4 Checkpoint Use with pp. 436–439 Lesson 4 Checkpoint 1. What are two tools that can help you see stars? 2. What do modern telescopes do? 3. What is a constellation? © Pearson Education, Inc. 3 Quick Study Chapter 15, Lesson 4 Checkpoint 103