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Lesson Plan Title: The Seasons Joe Trigone Colonial Middle School Problem to be studied: Identification of the mechanism behind the changing seasons. Content Standard: 3.4.10D(6) Content Objective(s): The objective of this lesson is for the students to understand the change of the seasons by way of modeling the Earth-Sun system. It is the first lesson of the year in which I incorporate quintessential earth science. The lesson is taught September ~21st (the Autumnal Equinox), interrupting my unit on the atom and chemical formulas. Teaching this particular lesson at this time serves several purposes, the most important of which I consider to be taking advantage of a "teachable moment." It also helps to prepare the students for more elaborate things to come throughout the school year by introducing such terms and topics as Newton's Laws, Copernicus, Kepler (and his Laws of Planetary Motion), and the constellations, including the role of astrology and the zodiac in the beginning study of the universe. This is a lesson that I will repeat in an increasingly elaborate fashion two more times throughout the year, on December 21st, and on March 21st, during the Winter Solstice and Vernal Equinox events, respectively. Process Standards: 3.1.10B(3) 3.1.10C(1&3) 3.1.10E(1) Process Objectives: In building student knowledge about natural phenomena, specifically in this case the change of seasons, the students are used as the model for the orbit of the earth around the sun. They will learn how and why the patterns of winter and summer occur. Assessment Strategies: (Evaluation) Formative Evaluation: While going through the lesson, make sure that students are building on concepts by questioning what season the globe is passing through and what lines on the globe the Sun is directly over during the pinnacle of each season. Students will also provide definitions for terms that are listed on board following the initial activity. The followDescribe concepts of models as a way to predict and understand science and technology. Apply patterns as repeated processes or recurring elements in science and technology. Describe patterns of change in nature, physical and man made systems. Explain essential ideas about the composition and structure of the universe. Suggested Grade Level: Recommended for 8th and 9th grade. However, this lesson could easily be modified for use in the lower grades. Younger students could very easily understand the core objective of the lesson; to understand the cause of the change of seasons in the northern and southern hemispheres. Time: One to two 45 minute class periods, depending on modifications. Materials: · Index cards (5x8in) · Globe (indicating latitude and longitude lines, as well as the Tropics of Cancer and Capricorn, the equator, Prime Meridian, Arctic and Antarctic Circles). · Flashlight (and a laser pointer light if lesson is modified, as indicated in the lesson write-up). · Notebooks · Masking tape · Clear cellophane tape. · Imagination

Lesson Plan up activity on the stars can be formatively assessed by observing where the students place their constellation cards (their zodiac) relative to Earth's orbit, by way of celestial/seasonal events indicated on the floor. Formative evaluations are discussed in more detail throughout the procedures. Summative Evaluation: After the second lesson on this subject (December 21st) students would complete a diagram indicating Earth at four locations along its orbit around the Sun. Each would indicate the axis/inclination, the Tropics of Cancer and Capricorn, and the Arctic and Antarctic Circles. They would also show where their particular Zodiac would be relative to the orbit, needing to show only the one to prove that they understand the concept. Procedures: Engage: Ask the students, what is so special about today? The answer sought is: the first day of fall. Most students who know that it occurs on this day have learned of the event on the radio or television, and they will most likely also know that the event occurred at a specific time. Query the students as to why it may have occurred at this specific time. Why did it happen [for example] at 5:32 EST? If a student does actually know the answer, ask the student to explain as best as he/she can. Then explain that we will build on this. Most, however, have no idea why the Autumnal Equinox event occurs at a given time. Explain to the students that many of their parents probably do not know either and that tonight you can go home and explain it to them. This is real stuff!!! Have the students stand and form a circle. While in the circle, I begin by sharing that it took many observers hundreds of years to somewhat figure out what was going on with the Earth-Sun system. Ask if anyone knows who Galileo was. Accept all answers. Also ask if anyone knows who Copernicus, Sir Isaac Newton, and Johannes Kepler were. Once again, accept all answers, and very briefly elaborate the importance of each of these historical figures in the study of astronomy and Earth's place in the solar system, i.e., Copernicus (a heliocentric universe), Galileo and Newton (providing proof, the latter also providing a means to measure longitude), and Kepler (Laws of Planetary Motion). Explore: Pick a volunteer to be the sun and give that person the flashlight and direct them to the center of the circle. At one point in the circle hand one student a globe. Ask the students to now model Earth's orbit around the Sun. Question which way they think it should go, left (clockwise as if viewed from above) or right (counterclockwise). Some students may know (or guess) that counterclockwise is the correct answer. As the students begin to move the globe in the correct direction around the Sun, explain that the technical name for this motion is called retrograde motion (write it on the board). Now query the students as to how many times the earth rotates on its axis while making one revolution around the sun. Most will know it is 365 days, but also ask which way it spins. Most will know this also, but question them on how they could prove it, comparing their model to the natural world. Guide them toward the answer of the Sun rising in the east, and to demonstrate this with the model shows clearly that the planet spins in a counterclockwise rotation, or retrograde rotation (write it on the board). As a side note, explain to them that Venus actually rotates on its axis in the other direction and that this is clockwise motion called prograde motion (write it on the board). Next, query the students as to which direction the globe's axis should be pointing during its trek around the model sun. Build on answers or guide students to the understanding that the axis stays in a fixed position relative to the walls of the classroom, not the model sun. Demonstrate this by taking the globe in hand, walking around the circle, and spinning the globe on its axis while keeping the axis fixed. This tilt is called the inclination (write it on the board). Make one revolution around the model sun. Once again, ask how many times it should spin by the time you return to the starting point. The correct answer should be 365. Now ask the students what some of the lines are on the globe. Initial answers should include the equator, latitude, and longitude (list on board). More in-depth answers should include the Arctic and Antarctic Circles, The Tropic

Lesson Plan of Cancer, The Tropic of Capricorn, and the Prime Meridian (also list these on the board). At this point, inform the students that all of these lines actually mean something and are important in the study of the seasons. They are also important in the study of science in many aspects; i.e., the charting of the stars and the invention of nonpendulum clocks for use in navigation (Newton, Harrison, and clocks. See websites). Explain: Have students once again pass the globe around the circle, this time making sure that the axis is always pointing in the same direction throughout its revolution. With the flashlight turned on to represent the sun and pointing toward the globe, ask the students to make predictions as to which season the globe is passing through along its orbit. Most student will see very clearly that as the northern hemisphere points away from the sun, this would represent winter, and summer in the southern hemisphere. On the other side of its orbit, representing six months later, the northern hemisphere would now be pointing toward the sun and thus experiencing summer and the southern hemisphere would be experiencing winter. As the globe is moving from summer toward winter in the northern hemisphere, it passes through the fall season. While it is in the middle of this passage, ask the students: at what part of the earth is the sun directly overhead in the fall? If necessary, lead them toward the answer that it is over the equator. Explain that the exact moment that the sun passes over the equator as it the earth is revolving in its orbit, that this is the Autumnal Equinox, or the first moment of fall. At this point you can demonstrate the remaining three benchmarks regarding the seasons: · The moment that the Winter Solstice occurs, ~December 21; this is when the sun is directly over the Tropic of Capricorn in the southern hemisphere. o At this time, the Sun's rays are illuminating the entire Antarctic Circle. This region will experience 24 hours of daylight on this day. On the opposite end of the Earth, the Arctic Circle will experience 24 hours of darkness on this date. The moment that the Vernal Equinox (Spring) occurs, ~March 21; the Sun is directly again over the equator. o At this time the North and South Poles are experiencing 12 hours of daylight and 12 hour of darkness. And the moment of the Summer Solstice occurs, ~June 21; the Sun is directly over the Tropic of Cancer in the northern hemisphere. o At this time, the Sun's rays are also illuminating the entire Arctic Circle. This region will experience 24 hours of daylight on this day. On the opposite end of the Earth, the Antarctic Circle will experience 24 hours of darkness on this date.



Once it seems apparent the most of the students understand the concepts, mark on the floor with masking tape and label the solstices and equinoxes, including dates. Prewritten index cards containing this information may also be used at this time. Have the students return to their seats. Now begin to define the terms on the board, asking students to offer definitions. Draw out the motion of the earth around the sun on the board--four representations of earth are sufficient. Be sure to point out the fixed axis on each representation, and once again question which season each pictorial is currently in. Ask for volunteers to come up to the board and label where they think the following: · Inclination · Tropics of Capricorn and Cancer · The Equator · Arctic and Antarctic Circles · Retrograde and Prograde Motion Elaborate: After completing the previous exercises, pass out an index card to each of the students. Ask them to list their date of birth along with their astrological sign on the card. If they want they can be creative and draw a picture of their particular zodiac sign. When all are finished, ask them to once again move back to the circle momentarily to

Lesson Plan refresh their memory of the Earth/Sun system. Then instruct them to place their individual index card sign on the wall behind the time of year they think it belongs, using the cellophane or masking tape. Students will undoubtedly place the labels in the incorrect location. For example, a student who happens to be an Aries (March 21st ­ April 20th) may place his/her index card behind the Vernal Equinox, corresponding with this label originally placed on the floor as indicated above. This is incorrect. The Aries index card should be placed behind the floor marking corresponding to six months later, behind the Autumnal Equinox. This is because the zodiac signs represent the constellations that the Sun passes in front of throughout the year. As such, these particular constellations cannot be seen from Earth during this time. In other words, during the time frame of March 21st, the Sun is between Earth and Aires, thus Aires will not be seen in the night sky. Have students place all of their signs in the correct location relative to the time of year based on this. At this point, reassemble the students in the circle and have them demonstrate the motion of earth's orbit once again. As it goes through its orbit, point out how the visible stars change position in the night sky throughout the year (by way of the constellations of the zodiac on the surrounding wall). Students will quickly get this concept. Modifications and Comments: 1. A laser pointer may be used in place of the flashlight (sun). This will help with identifying the angle at which the sun is overhead at the Tropics of Cancer/Capricorn and the equator during the pinnacle of each season, but it is recommended that the teacher then play the role of the Sun. Students may not responsibly use the laser pointer, and this can damage the eyes if used improperly. The lesson above can be taught in one class period. (Yes, I have done it with time to spare.) You may, however, modify it to either run over the course of two days, or you may exclude the section covering the Zodiac if necessary. Facilitating this lesson to the younger grades can also be useful by excluding the material on the Tropics of Cancer and Capricorn, and the Arctic and Antarctic Circles. However, these students may enjoy working with the Zodiac. The lesson can also be expanded to include the importance of the Sun's altitude regarding weather changes at different latitudes (see website, Seasons #4 below). It may also preface lessons on Kepler's Laws. Exact dates of the four seasonal dates are different during leap years, and are listed on most calendars.


3. 4.

Informational Web Sites: Seasons: 1. 2. 3. 4. Kepler: 1. 2. 3. Galileo & Copernicus: 1. 2. Newton: 1. 2. Clocks and longitude: 1. 2.


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