Earth, Moon, and Sun Study Guide Key

Earth, Moon, and Sun Study Guide KEY Do not write on this page. Use it to check your answers for detail and accuracy. Pages 84-85 (Use the diagrams in the foldable!): Goal #4: Explain the seasons in the Northern and Southern Hemisphere in terms of the tilt of Earth’s axis relative to the Earth’s revolution around the sun. 1. What is the angle of the tilt in Earth’s axis? 23.5° 2. Explain how the tilt in the Earth’s axis changes the amount of sunlight an area receives throughout the year. (When does the Northern Hemisphere receive more light? Why? When does it receive less? Why?) Because the axis is tilted, the earth’s surface gets a different amount of light at different times. The Northern hemisphere gets more sunlight (has longer days) when the northern end of the axis is pointing towards the sun. This is summer in the northern hemisphere. The northern hemisphere receives less sunlight (has shorter days) when the northern end of the axis in pointing away from the sun. This is our winter. 3. How do the lengths of daytime/nighttime compare on the winter and summer solstices? On the day of the Winter Solstice, the hemisphere has its shortest day of the year (or the least hours of sunlight). On the Summer Solstice, it has the longest day of the year (or the most hours of sunlight). 4. How do the lengths of daytime/nighttime compare on the spring and fall equinoxes? During the equinoxes, both hemispheres experience daytime and nighttime that are of equal length. 5. Explain how changes in the angle of impact of light hitting the Earth’s surface causes temperatures to vary. (What happens when the light hits at a direct angle? Steep angle?) When sunlight hits at a direct angle, the energy is concentrated in a small area, which leads to warmer temperatures. When sunlight hits at an indirect or steep angle, the energy is spread out over a larger area. This leads to cooler temperatures. 6. Label Diagram A to show where winter, summer, spring and fall are occurring in the Northern Hemisphere: Winter: Position C Summer: Position A Spring: Position D Fall: Position B Pages 86-87: Goal 5. Explain the phases of the Moon in terms of the relative positions of the Earth, Sun, and Moon. 7. Tell how much of the moon’s surface is always lit by the sun: Half 8. Tell why the Moon’s shape seems to change: The “shape” that we see depends on how much of the sunlit part of the moon is facing Earth. (The amount of the lit part that we can see changes as the moon revolves around the Earth.) 9. Tell why we always see the same side of the moon: Because the moon rotates and revolves at the same rate, (29.5 days), the moon always keeps the same side towards the Earth. 10. Explain why a “New Moon” is completely dark: A new moon is caused when the lit half of the moon is on the far side, facing away from Earth. 11. Identify the position/name of each of the 8 phases of the moon. A. Full Moon B. Waning Gibbous C. Last/3rd Quarter D. Waning Crescent E. New Moon F. Waxing Crescent G. 1st Quarter H. Waxing Gibbous Pages 88-89: Goal 6. Explain the relationship between the Earth, Sun, and Moon as they relate to eclipses and tides. 12. What causes the tides? The gravitational pull between the Earth, Sun, and Moon cause the tides. 13. Explain why there are two high tides at any given time on Earth’s surface. Gravity pulls the water on Earth towards the Moon, causing a high tide on the side towards the moon. The Earth also gets pulled towards the moon, leaving some water behind, which causes a second high tide on the side away from the Moon. 7. What is a “spring tide”? It is when the moon, sun, and Earth are in a straight line; it is the highest possible high tide 8. What is a “neap tide”? It’s when the moon, sun, and Earth form a right angle; it is the lowest possible high tide. 9. How is a solar eclipse different from a lunar eclipse? Any reasonable answer. May include: lunar eclipses are visible over a large area, but solar eclipses can only be seen from a small path on Earth’s surface; Solar eclipses are where the moon covers the sun, blocking its light, and lunar eclipses are when the moon moves into Earth’s shadow. 10. Identify the position of the moon during each of the following events: A&C spring tides (2) D&B neap tides (2) A solar eclipse C lunar eclipse