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Download 10-1 The Plant Kingdom - yms
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Chapter 12 Earth, Moon, and Sun Objective 1. Describe how gravity helps in forming and maintaining the shapes of planets, stars, and the solar system 2. Know that stars are the source of light for all bright objects in space; know that the Moon and planets shine due to reflecting of sunlight 3. Know and be able to describe the position, size, motion, etc of objects in the solar system Earth’s Movement Two ways: - rotation: spinning of Earth on the axis (line that passes through Earth’s center, North and South poles) o causes day and night (rotate eastday on side of Earth facing the sun; Earth turns to east sun sets in west) o 24 hours to rotate once - revolution: movement of one object around the other o one year=one complete revolution o orbit: revolution around the sun Earth’s Seasons winter, spring, summer, autumn - warmer near the equator because the sunlight hits most directly there - seasons: tilted axis results in seasons o June=summer in northern hemisphere because it tilts towards the sun - Solstice: twice a year the sun reaches its farthest position either north or south of the equator (june 21summer solstice in northern hemisphere, day is the longest; winter solstice in southern hemisphere, shortest day) - Equinox: hemispheres are not tilted toward or away from the sun; noon sun is directly overhead; equal night Universal Law of Gravitation: every object in the universe attracts every other object - mass and the distance between two objects affects the strength of gravity Gravity Inertia object’s resistance to a change in motion - inertia and gravity keep Earth in orbit around the sun and the moon in orbit around Earth Motion of the Moon phases of the moon, eclipses and tides are due to the changing relative positions of the moon, Earth, and the sun - phases are the different shapes of the moon seen from Earth (full, half) - sunlight lights up the moon so the phases of the moon that we see depends on how much of the sunlit side of the moon faces Earth - eclipse occurs when the moon’s shadow hits hurts or vice versa - solar eclipse: sunlight is blocked from Earth because the moon passes directly between Earth and the sun Tides tides occur because of the differences in the moon’s gravitational pull on different parts of Earth - spring tide: gravity of sun and moon combine to produce a tide with the greatest difference between consecutive low and high tide - neap tide: tide with least difference between consecutive low and high tide Moon’s Surface maria - dark, flat areas - hardened rock formed from lava - looks like oceans or seas (thought Galileo) craters - large round pits - impact of meteoroids highlands - mountains Characteristics dry and airless, small, large variations in temperature
