Reasons for Seasons Worksheet Answer Key

REASONS FOR SEASONS Name: Keep for 3rd Qtr. Kotates day revolve Sun 365 year 24 Northern Winter Tilt southem hemisphere summer Polaris circle coldier 23.5 warmer Winter summer solstice equinox axis elliptical Planet Earth rotates. time a day year for the Earth to once around its axis every 24 There are 365 days in a revolve once around the years old [enter your own age], then I have made my life. sun 12/13 hours. We call this period of year If I am It takes one 12/13 trips around the sun during Earth's orbit around the sun traces out an almost perfect Circle Thus the distance between the sun and Earth does not change very much over the course of a year. So the reason that temperatures are Warmer in the summer and colder in the winter is the tilt of Eas rotation axis. Earth's seasons are NOT caused by being closer or farther from the sun. Earth's rotational axis is tilted 23.5 degrees toward a distant star called Polaris (The North Star). As Earth moves around the sun, Earth's North Pole stays pointed toward this star, which is 500 light-years from our solar system. Earth's axis remains tilted toward Polaris, but how Earth is leaning relative to the Sun changes as Earth moves in its orbit around the Sun. When Earth is located on one side of the Sun, the tilt causes the northern hemisphere to be leaning toward the sun. When earth is on the opposite side of the sun, this same tilt towards Polaris causes the Northern Hemisphere to be leaning away from the sun. When the northem hemisphere is leaning towards the sun, the season is Summer in the Northern hemisphere and winter in the southern hemisphere. When the northern hemisphere is leaning away from the sun, the season is and summer in the Winter Southern in the northern hemisphere hemisphere. When we are leaning away from the sun, as in the season of winter the sun appears lower less [higher/lower] in the sky. This means the sun will spend [less/more] time above the horizons (rising later and setting earlier), and thus there will be fewer daylight hours and less time to warm the Earth. The day of the year with the least [least/most] daylight hours is December 21, the first day of winter (in the Northern Hemisphere). This day is also called the winter solstice. When we are leaning toward the sun, as in the season of higher more Summer the sun appears [higher/lower] in the sky. This means the sun will spend [less/more] time above the horizons (rising earlier and setting later), and thus there will be more daylight hours and more time to warm the Earth. It is also true, that when the sun is higher in the sky, the sun's rays impact earth at a steeper angle and are more [less/more] intense than when the sun is lower in the sky. This also helps to explain why it is warmer in summer and colder in winter. The day of the year with the Most [least/most] daylight hours is June 21st, the first day of summer (in the northern hemisphere). This day is also called the summer Soltice When earth is neither leaning towards nor away from the sun, we have the fall and spring eqiunox when daylight and nighttime hours are about equal. For Earth, the following phrase is a way to remember the reason for colder and warmer seasons: "Length of days; angle of ray; nothing to do with how far away". But, what about the seasons on Mars? Mars' rotational axis of mars around the sun is more is tilted about the same amount as the Earth's, but the orbit elliptical (like an oval). Thus Mars' distance from the sun varies a lot more than Earth's distance from the sun. This means that both the tilt of the Mars, Rotation axis and its closer and farther distances from the sun are important to consider in determining the more extreme natures of Martian seasons.