Phases and Eclipses Lesson 4.pptx

Phases and Eclipses Lesson 4 Holt What Causes the Moon’s Phases? What Are Eclipses? BLOG Posted by: Nicole Location: Bernhard’s Bay, New York One night, my mom, dad, and I were coming home from eating dinner. When we got out of the car, we saw that the moon was turning red. We looked at the mo...

Phases and Eclipses Lesson 4 Holt What Causes the Moon’s Phases? What Are Eclipses? BLOG Posted by: Nicole Location: Bernhard’s Bay, New York One night, my mom, dad, and I were coming home from eating dinner. When we got out of the car, we saw that the moon was turning red. We looked at the moon for a while. Then our neighbor called and said that it was a lunar eclipse. It was an amazing sight. Think about your own experiences as you answer the question below. What is the most interesting or universal event you have ever seen in the sky? The most interesting event that I’ve seen in the sky was What Causes the Moon’s Phases? Have you ever been kept awake by bright moonlight? The light streaming through your window actually comes from the sun! The moon does not shine with its own light. Instead, it reflects light from the sun. When the moon is full, this light may be bright enough to read by! But at other times, the moon is just a thin crescent in the sky. The different shapes of the moon you see from Earth are called phases. Phases are caused by the motions of the moon around Earth. Motions of the Moon When you look up at the moon, you may see what looks like a face. What you are really seeing is a pattern of light-colored and dark-colored areas on the moon’s surface that just happens to look like a face. Oddly, this pattern never seems to move. The same side of the moon, the “near side,” always faces Earth. The “far side” of the moon always faces away from Earth. Why? The answer has to do with the moon’s motions. Motions of the Moon Like Earth, the moon moves through space in two ways. The moon revolves around Earth and also rotates on its axis. The moon rotates once on its axis in the same time that it takes to revolve once around Earth. Thus, a “day” on the moon is the same length as a month on Earth. For this reason, the same side of the moon always faces Earth, as you can see on the next slide. Motions of the Moon As, the moon orbits Earth, the relative positions of the moon, Earth, and sun change. The changing relative positions of the moon. Earth, and sun cause the phases of the moon. Phases of the Moon Half the moon is almost always in sunlight. But since the moon orbits Earth, you see the moon from different angles. The phase of the moon you see depends on how much of the sunlit side of the moon faces Earth. Phases of the Moon During the new moon phase, the side of the moon facing Earth is not lit. As the moon revolves around Earth, you see more of the lit side of the moon, until you see all of the lit side. As the month continues, you see less of the lit side. You can see these changes on the next slide. About 29.5 days after the last new moon, a new moon occurs again. Assess Your Understanding Moon phases are caused by Complete the sentence below What Are Eclipses? The moon’s orbit around Earth is slightly tilted with respect to Earth’s orbit around the sun. As a result, the moon travels above and below Earth’s orbit. But on rare occasions, Earth, the moon, and the sun line up. What Are Eclipses? When an object in space comes between the sun and a third object, it casts a shadow on that object, causing an eclipse (ih KLIPS) to take place. There are two types of eclipses: solar eclipses and lunar eclipses. (The words solar and lunar come from the Latin words for “sun” and “moon.”) Solar Eclipses During a new moon, the moon lies between Earth and the sun. A solar eclipse occurs when the moon passes directly between Earth and the sun, blocking sunlight from Earth. The moon’s shadow then hits Earth. Solar Eclipses Total Solar Eclipse The very darkest part of the moon’s shadow is the umbra (UM bruh). You can see how the umbra strikes Earth on the slide. Within the umbra, the sun’s light is completely blocked. Only people within the umbra experience a total solar eclipse. During a total solar eclipse, the sky grows as dark as night. The air gets cool and the sky becomes an eerie color. You can see the stars and the solar corona, which is the faint outer atmosphere of the sun. Solar Eclipses Partial Solar Eclipses The moon casts another part of its shadow that is less dark than the umbra. This larger part of the part of the sun is visible from Earth. During a solar eclipse, people in the penumbra see only a partial eclipse. Solar Eclipse The diagram shows the moon’s penumbra and umbra during an eclipse. It is not drawn to scale. Relate Text and Visuals Label Total Eclipse and Partial Eclipse. Lunar Eclipses During most months, the moon moves near Earth’s shadow but not quite into it. A lunar eclipse occurs at a full moon when Earth is directly between the moon and the sun. During a lunar eclipse, Earth blocks sunlight from reaching the moon. Lunar eclipses occur only when there is a full moon because the moon is closest to Earth’s shadow at that time. Total Lunar Eclipses Like the moon’s shadow in a solar eclipse, Earth’s shadow has an umbra and a penumbra. When the moon is in Earth’s umbra, you see a total eclipse. Unlike a total solar eclipse , a total lunar eclipse can be seen anywhere on Earth that the moon is visible. So you are more likely to see a total lunar eclipse than a total solar eclipse. Partial Lunar Eclipses For most lunar eclipses, Earth, the moon, and the sun are not quite in line, and only a partial lunar eclipse results. A partial lunar eclipse occurs when the moon passes partly into the umbra of Earth’s shadow. The edge of the umbra appears blurry, and you can watch it pass across the moon for two or three hours. P T P Seasons and Shadows How do Earth, the moon, and the sun interact? Look at the diagram below. (The diagram is not to scale.) Identify what season it is in the Northern Hemisphere, what the phase of the moon is, and what kind of eclipse, if any, could occur. Season Moon Phase Eclipse Assess Your Understanding Explain A (solar/lunar) eclipse occurs when the moon passes into Earth’s shadow. A (solar/lunar) eclipse occurs when Earth passes into the moon’s shadow. Finish the sentence Today I learned