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Download the Moon? The Moon has no wind or water to erode the craters
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Chapter 17 Study Sheet 1. If you think you see a shooting star at night, what did you really see? Meteor 2. Why do craters last for millions of years on the surface of the Moon? The Moon has no wind or water to erode the craters 3. In a 24-hour period, Earth completes one rotation on its axis. 4. What shape is the orbit of the Earth around the Sun? elliptical 5. Write the correct order of the planets from the Sun? Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto 6. What is gravity? It is the Earth’s pulling force that makes things fall or gives things weight. 7. How do the planets stay in their orbits? The gravitational pull of the Sun keeps the planets in their obits. 8. What causes the temperatures at the North and South poles to remain so cold throughout the year? The tilt of the Earth on its axis. 9. Why do most of the asteroids in the asteroid belt stay in the asteroid belt? Jupiter’s gravity Short Answer: 10. What causes Mars and Saturn to have years of different length? Mars and Saturn have years of different lengths because their revolutions around the Sun take different amounts of time. Mars is closer to the Sun, travels faster, and in a smaller orbit. Saturn moves more slowly and has a longer orbit. 11. How does Earth rotation on its axis help keep the planet at proper temperature for life? The Earth rotates quickly on its axis, causing day and night to quickly follow each other in a short period of time. This is what helps keep temperatures mild enough for life. If Earth rotated more slowly, days would be too long and hot and nights would then be too long and too cold. 12. Be able to draw an illustration to show which hemisphere is having summer or winter.