seegongsik
Grade 6 (age 11-12)

grade 6 Earth's Rotation & Revolution

Earth seems to stay still, but it never stops moving in two ways. Spinning once a day is rotation: the side facing the Sun has day and the other side has night. Rotation is also why the Sun seems to rise in the east and set in the west. Going once around the Sun each year is revolution, and because Earth travels with its axis tilted about 23.5°, the seasons change. In the first picture, change the time and watch one spot move between day and night; in the second, change the month and see where Earth is around the Sun in each season.

Rotation: why day turns into night

12:00
🌍 What is rotation?
①Earth spinning around its own axis is called rotation.
②One turn takes about 24 hours, which is one day.
③The side facing the Sun has day and the far side has night, so rotation makes day and night repeat.
④Earth turns from west to east, so the Sun and Moon seem to rise in the east and set in the west.

Revolution: why the seasons change

6
🔄 What is revolution?
①Earth traveling around the Sun is called revolution. One trip takes about 365 days, which is one year.
②Earth's axis is tilted about 23.5° and always points the same way.
③When the Northern Hemisphere leans toward the Sun (around June), the midday Sun is high and days are long, so it is summer.
④When it leans away from the Sun (around December), the Sun stays low and days are short, so it is winter.
⑤The distance between Earth and the Sun is not the main reason for the seasons.

Summary

Rotation Period
One rotation = about 24 hours (one day)
This is why day and night repeat.
Revolution Period
One revolution = about 365 days (one year)
Together with the tilted axis, this is why the seasons change.
🎯 Key points
①Rotation: Earth spinning by itself, which gives us day and night.
②Revolution: Earth traveling around the Sun.
③Rotation takes about 24 hours; revolution takes about 365 days.
④Because Earth revolves with its axis tilted, the seasons change.
⑤In summer the midday Sun is high and days are long; in winter the Sun is low and days are short. You will look at the Sun's height and day length more closely in the unit on seasonal change.

Examples and Unit Test

Example 1
What is Earth spinning once a day by itself called, and what does it make repeat?
1
Earth spinning by itself is called rotation.
2
The side facing the Sun has day and the far side has night, so day and night repeat.
▸ Rotation / day and night
In the first picture, set the time to 12:00 and the yellow dot sits right in front of the Sun; set it to 0:00 and it is on the opposite side.
Example 2
How long do Earth's rotation and revolution each take, and what does revolution cause?
1
Rotation takes about 24 hours and revolution takes about 365 days.
2
Because Earth revolves with its axis tilted, the seasons change.
▸ Rotation about 24 hours (a day), revolution about 365 days (a year) / the change of seasons
In the second picture, move to June and the arrow tip of the axis (the North Pole) leans toward the Sun; move to December and it leans away.
Unit-test style
Which statement about Earth's rotation and revolution is correct?
①Rotation makes the seasons change.
②Earth rotates once in about a day (24 hours).
③Revolution means Earth spinning by itself.
④The side facing the Sun has night.
⑤Earth revolves around the Sun once in about a day.
▸ ② Earth rotates once in about a day (24 hours).
1
Earth rotates once in about 24 hours, which gives us day and night.
2
The seasons come from revolution with a tilted axis (①), revolution means going around the Sun (③), the side facing the Sun has day (④), and one revolution takes about a year (⑤).
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