4. Revolution
• Revolution = movement of an object in
space around another object.
Natural Sciences and Technology - Grade 6
5. Earth’s Rotation
• Turning of Earth on its
own axis.
• The Earth’s axis is
tilted.
• Causes day and night.
• Takes the Earth 24
hours to rotate.
Natural Sciences and Technology - Grade 6
6. Day and Night
• The Sun gives off light and heat.
Natural Sciences and Technology - Grade 6
• The Sun sets in the west and rises in the
east.
7. Earth’s Revolution
• Earth orbits the Sun.
• Earth takes 365 ¼ days to go
around the Sun.
• The revolution of the Earth around
the Sun causes the seasons
(summer, winter, autumn and
spring).
• As the Earth completes one orbit
of the Sun, different parts tilt
towards and away from the Sun.
• Orbit is oval shape.
Natural Sciences and Technology - Grade 6
9. Movement of Earth, Moon and Sun
Natural Sciences and Technology - Grade 6
Editor's Notes
Image: www.windows2universe.org
Image: www.windows2universe.org
The rotation is like a wheel on a bicycle. It takes 24 hours for Earth to move around once (make a full circle). You could ask a learner to stand in front and in the same position slowly turn around starting and ending in the same position and explain it takes Earth 25 hours to do the same thing.
Do the activity where they colour in where it is day or where there is night.
Explain that the side of Earth facing the sun is lit up and the side of Earth away from the Sun is dark (shadow) so it is night time. The next slides shows this. In other words only one side of the Earth gets light at a time.
Remind the learners that all the planets move around the Sun. Remind them from the first work they did that the planets all have different times to make one lap around the Sun. It takes one year (365 ¼ days). The year is divided into 12 months and the twelve months are divided into four seasons = summer, autumn, winter, spring. The next slide shows a position on the globe and how with the Earth revolving the seasons change.
Seasons occur because Earth receives different amounts of heat and light, because the track is oval NOT round so the orbit path is elliptical. At times Earth is closer to the Sun and others further away. So it is cooler when further away and warmer when closer to the Sun.
Seasons occur because the pathway is elliptical and because Earth is tilted, the side that faces the Sun has summer and the side away from the Sun has winter. Seasons change around the 21st of June, September, December & March.
Using the Globe and light source now not only turn Earth on its axis but move it around the light source (here a lamp with no shade will work better).
The Figure shows how the Earth orbits the Sun, the Earth rotates, the Moon orbits the Earth.
Now would be the best time to either do some revision questions or the activities as set out in the guide.