Presentation on theme: "Astronomy The study of the moon, stars, and other objects in space Study the movements of the sun, and moon as they appear to travel across the sky Will."— Presentation transcript:
Astronomy The study of the moon, stars, and other objects in space Study the movements of the sun, and moon as they appear to travel across the sky Will look at seasons and phases of the moon
Questions to Ponder 1. What causes day and night? 2. What causes the seasons?
Day and Night Demo with globe and light bulb Day and Night occur because the Earth rotates on its axis Axis- the imaginary line that passes through earth's center and north and south poles Rotation- Earth spinning on it's axis (one rotation takes 24 hours)
Earth's Movement In addition to the Earth rotating on its axis, the Earth is also traveling around the sun Revolution- Earth traveling around the sun One Revolution around the sun takes 365 ¼ days (On our calendar, this equals one year)
Earth's Orbit As the Earth revolves around the sun, can it go wherever it wants to go? NO!!!! Stays in one path (called the Earth's orbit) The Earth's orbit is almost circular
Why do We Have Seasons??? Has to do with the Earth's revolution around the sun and the tilt of the Earth's axis 1 st Question: Why is the equator warmer than the poles?
Why do we have seasons??? 2 nd Question: What would the tilt of Earth's axis have to do with seasons? As Earth revolves around the sun, its axis is titled away from the sun for part of the year and toward the sun for part of the year
Seasons... Northern Hemisphere tilted toward the sun= Summer in Northern Hemisphere and Winter in Southern Hemisphere Northern Hemisphere tilted away from the sun= Winter in Northern Hemisphere and Summer in Southern Hemisphere Common Misconception: The seasons are caused by how far away the Earth is from the sun (NOT TRUE!!!!)
Seasons... There are 4 important dates that mark summer, fall, winter, and spring. What are they??? June 21 st and December 21 st (beginning of summer and beginning of winter) Documents the longest day of the year and the shortest day of the year Solstice: when the sun is directly overhead at noon time ( No shadow!!!)
Seasons... Half way between the solstices, neither hemisphere is tilted toward or away from the sun Noon sun is directly overhead at the equator There are equal amounts of daylight and darkness Equinox: means “equal night” Vernal equinox (spring) March 21 st Autumnal equinox (autumn) September 23