4.4 Earth and the Solar System

• Community stories and scientific theories of the origin of the earth (passing star theory and nebula cloud theory)
• Size, shape and position of the Earth in the solar system
• Rotation of the earth and effects on human activities
• Revolution of the earth and effects on human activities
• Internal structure of the earth: crust, mantle and core

• describe the origin of the earth
• explore the size, shape, and position of the Earth in the solar system
• examine the effects of rotation and revolution of the earth on human activities
• illustrate the internal structure of the earth in the solar system
• appreciate the effects of rotation and revolution of the earth on human activities

“Why is it important to understand the solar system?”

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1. Origin of the earth
   40 min · 1 practice tasks · quiz
   Describe community stories of how the earth began, then the passing star theory and the nebula cloud theory.
2. Size, shape and position of Earth
   40 min · 1 practice tasks · quiz
   Earth is the third planet from the Sun, an oblate spheroid about 12 740 km across at the equator, in the habitable zone.
3. Rotation and human activities
   40 min · 1 practice tasks · quiz
   Rotation is the 24-hour spin that gives day and night, local time and a daily temperature swing, which shape work, rest and safety.
4. Revolution and human activities
   40 min · 1 practice tasks · quiz
   Revolution is the yearly orbit (about 365.25 days). With axial tilt it gives seasons, a calendar, leap years and farming cycles.
5. Internal structure of the earth
   40 min · 1 practice tasks · quiz
   Draw crust, mantle and core, then appreciate that rotation and revolution on this layered planet shape human life.