Chapter 3 – Motions of the Earth

These NCERT Class 6 Geography Chapter 3 notes explain the movements of the Earth. The chapter focuses on rotation, revolution, seasons, leap year, solstice, and equinox in a simple way.

1. Meaning of motions of the Earth

•  The Earth is not stationary.
•  It keeps moving continuously in space.
•  The Earth has two main motions.
•  These motions are called rotation and revolution.
•  Both motions are essential for life on Earth.
•  Like a spinning top, the Earth moves while rotating and revolving.

2. Rotation of the Earth

•  Rotation means the Earth spins on its own axis.
•  The axis is an imaginary line passing through the North Pole and South Pole.
•  The Earth rotates from west to east.
•  One complete rotation takes 24 hours.
•  This rotation causes day and night.
•  One rotation makes one day.

3. Effects of rotation

•  When a part of the Earth faces the Sun, it experiences day.
•  When it faces away from the Sun, it experiences night.
•  Rotation explains the regular cycle of day and night.
•  Due to rotation, the Sun appears to rise in the east.
•  The Sun appears to set in the west.
•  This apparent movement is due to Earth’s rotation.

4. Revolution of the Earth

•  Revolution means the Earth moves around the Sun.
•  The path followed by the Earth is called an orbit.
•  One complete revolution takes 365¼ days.
•  This duration makes one year.
•  Revolution is responsible for the change in seasons.
•  The Earth maintains a fixed path while revolving.

5. Leap year

•  The extra ¼ day is added every year.
•  These extra hours are added once in four years.
•  That year has 366 days.
•  Such a year is called a leap year.
•  In a leap year, February has 29 days.
•  Leap years help maintain calendar accuracy.

6. Axis and tilt of the Earth

•  The Earth’s axis is tilted at 23½°.
•  This tilt remains constant during revolution.
•  Tilt affects the amount of sunlight received.
•  The tilt works together with revolution.
•  It causes changes in seasons.
•  Without tilt, seasons would not occur.

7. Seasons

•  Seasons occur due to the tilt of the Earth’s axis.
•  They are also caused by the revolution of the Earth around the Sun.
•  Different parts of the Earth receive different amounts of sunlight.
•  Seasons change regularly every year.
•  Seasons affect climate and daily life.
•  The cycle of seasons is predictable.

8. Summer solstice

•  The Summer Solstice occurs on 21st June.
•  It marks the longest day in the Northern Hemisphere.
•  The night is the shortest on this day.
•  The Sun’s rays fall directly on the Tropic of Cancer.
•  Northern Hemisphere receives maximum sunlight.
•  Summer season begins in many regions.

9. Winter solstice

•  The Winter Solstice occurs on 22nd December.
•  It marks the shortest day in the Northern Hemisphere.
•  The night is the longest on this day.
•  The Sun’s rays fall directly on the Tropic of Capricorn.
•  Northern Hemisphere receives less sunlight.
•  Winter season begins in many regions.

10. Equinoxes

•  During an equinox, day and night are equal everywhere.
•  The Spring Equinox occurs on 21st March.
•  The Autumn Equinox occurs on 23rd September.
•  The Sun shines directly on the Equator on these days.
•  Both hemispheres receive equal sunlight.
•  Equinoxes mark seasonal transitions.

11. Important dates

•  One rotation of the Earth takes 24 hours.
•  One revolution of the Earth takes 365¼ days.
•  Summer Solstice occurs on 21st June.
•  Winter Solstice occurs on 22nd December.
•  Equinoxes occur on 21st March and 23rd September.

12. Important keywords

•  Rotation is the spinning of the Earth on its axis.
•  Revolution is the movement of the Earth around the Sun.
•  Axis is an imaginary line joining the poles.
•  Orbit is the path of revolution.
•  Leap year has 366 days.
•  Solstice and equinox are important seasonal events.

13. Why this chapter is important

•  This chapter explains day and night.
•  It helps understand the change of seasons.
•  It explains the concept of a leap year.
•  It forms the base for understanding climate.
•  It helps in time calculation.
•  It is frequently asked in school exams and BPSC / State PCS foundation.

This chapter explains the scientific reasons behind day and night and seasonal changes, which are essential for climate studies.

Continue reading Class 6 Geography Chapter 4 – Maps to learn map reading skills.

FAQs

Q1. What causes day and night?
Rotation of the Earth on its axis.

Q2. Why do seasons occur?
Due to Earth’s tilt and revolution around the Sun.