Science: 4-3.4 Explain how the tilt of Earth’s axis and the revolution around the Sun results in the seasons of the year.
Earth has distinct seasons as a result of the tilt of its axis and its revolution, or orbit, around the Sun.
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Seasons of the Year
Essential Question:
How does the tilt of Earth’s axis and the revolution around the Sun result in the seasons of the year?
Causes of Four Seasons
Changes in season and temperature happen because of Earth’s movement and tilt. You know that Earth rotates, or spins on its axis. Earth also revolves around the sun. To revolve means to move in a path around another object. Earth takes one year to go all the way around the sun one time. One year is about 365 days.
Notice in the diagram that Earth’s axis is tilted. As Earth revolves, different parts of the Earth tilt toward the sun.
Notice Earth’s tilt when it is summer in the northern half of Earth. This part of Earth, where we live, is called the Northern Hemisphere. The Northern Hemisphere is tilted toward the sun. Now notice Earth’s tilt when it is winter in the northern half of Earth. The Northern Hemisphere is tilted away from the sun.
Earth’s tilt has the same effect on the southern half of Earth which is called the Southern Hemisphere. The two hemispheres have opposite seasons.
During spring and fall, neither hemisphere is tilted toward the sun. Temperatures in both hemispheres tend to be mild.
Earth’s distance from the sun does not affect the seasons. Instead the part of Earth tilted toward the sun gets more direct sunlight. In summer, the sun’s rays travel directly to Earth’s surface. In winter, the rays are more slanted. They travel farther through Earth’s atmosphere. They lose some energy along the way.
Number of Daylight Hours
Earth’s tilt also causes the number of daylight hours to change during the year. This change affects temperature. In summer, there are more hours of daylight. The sun heats Earth’s surface longer each day in summer. In winter, there are fewer hours of daylight. The sun heats Earth’s surface for a shorter time each day in winter.
Essential Question:
How does the tilt of Earth’s axis and the revolution around the Sun result in the seasons of the year?
Causes of Four Seasons
Changes in season and temperature happen because of Earth’s movement and tilt. You know that Earth rotates, or spins on its axis. Earth also revolves around the sun. To revolve means to move in a path around another object. Earth takes one year to go all the way around the sun one time. One year is about 365 days.
Notice in the diagram that Earth’s axis is tilted. As Earth revolves, different parts of the Earth tilt toward the sun.
Notice Earth’s tilt when it is summer in the northern half of Earth. This part of Earth, where we live, is called the Northern Hemisphere. The Northern Hemisphere is tilted toward the sun. Now notice Earth’s tilt when it is winter in the northern half of Earth. The Northern Hemisphere is tilted away from the sun.
Earth’s tilt has the same effect on the southern half of Earth which is called the Southern Hemisphere. The two hemispheres have opposite seasons.
During spring and fall, neither hemisphere is tilted toward the sun. Temperatures in both hemispheres tend to be mild.
Earth’s distance from the sun does not affect the seasons. Instead the part of Earth tilted toward the sun gets more direct sunlight. In summer, the sun’s rays travel directly to Earth’s surface. In winter, the rays are more slanted. They travel farther through Earth’s atmosphere. They lose some energy along the way.
Number of Daylight Hours
Earth’s tilt also causes the number of daylight hours to change during the year. This change affects temperature. In summer, there are more hours of daylight. The sun heats Earth’s surface longer each day in summer. In winter, there are fewer hours of daylight. The sun heats Earth’s surface for a shorter time each day in winter.
Learning Tasks & Assessments:
Read Reading A-Z Text, Sun, Earth, and Moon. Reading A-Z (Pg. 5-7) or another text) and illustrate a season based on the description or drawing of the tilt of the axis. (DOK 1) Notebook Entry: Construct a cause-and-effect model of the ways that Earth’s seasons are affected by the tilt of Earth’s axis and the revolution around the Sun. (DOK2) (SEP 2) Notebook Entry: Construct a model of the Earth and Sun during each of the four seasons. (DOK 3) Formative Assessment: Write Like a Scientist: Explain how the tilt of the Earth’s axis and the revolution around the Sun results in the seasons of the year. (DOK 2) Using the app “Shadow Puppet Edu” students sequence the seasons, explain the cause and effect of seasons, and recall information about the Earth’s axis. Students add in music, recordings of voices, photos, and videos to support claims. Assessment Guidelines: The objective of this indicator is to explain how the tilt of Earth’s axis and the revolution around the Sun results in the seasons of the year; therefore, the primary focus of assessment should be to construct a cause-and-effect model of the ways that Earth’s seasons are affected by these two factors. However, appropriate assessments should also require students to recall information about Earth’s axis or revolution; classify by sequencing the seasons; or infer or illustrate a season based on the description or drawing of the tilt of the axis. |
Resources:
Reading A-Z: “Sun, Earth, and Moon” (Pg. 5-7) Discovery Education Videos: Nature’s Power: Seasons of the Year The Movement of the Earth Cycles and Seasons The Reasons for the Seasons Elements of Earth Science: The Universe and the Solar System: The Earth’s Orbit Write Like a Scientist: - Why are There Different Seasons? The effects on Earth due to the change in the amount of sunlight caused by the tilt of Earth’s axis.
o Summer occurs when part of Earth is tilted most toward the Sun o Autumn and spring occur when neither part of Earth is pointed directly toward or away from the Sun. o Winter occurs when part of Earth is tilted away from the Sun. o The sequence of the seasons during the year is summer, autumn/fall, winter, and then spring. |