🌍 Earth, Moon and the Sun – Chapter Summary with NCERT Solution PDF
 |
| Earth, Moon and The Sun (AI Generated) |
The chapter “Earth, Moon and the Sun” explains how the Earth moves, why we experience day and night, seasons, changing night sky, and how solar and lunar eclipses happen. This summary covers all important concepts in simple, easy words and is perfect for revision.
🌅 Rotation of the Earth – Why Day and Night Happen
The Earth spins on its own axis. This movement is called rotation.
It takes 24 hours to complete one full rotation.
- The Earth rotates from West to East, so the Sun appears to rise in the East and set in the West.
- Only the half of the Earth facing the Sun has daytime.
- The other half, which faces away from the Sun, has night.
Just like a merry-go-round, when the Earth spins, things seem to move in the sky. The rising and setting of the Sun, Moon, and stars are only apparent movements caused by Earth’s rotation.
🌌 The Changing Night Sky
At night we see stars. But have you noticed that different stars appear in different months?
This happens because the Earth is constantly rotating AND revolving.
Some stars like the Pole Star (Dhruva Tara) appear fixed because Earth’s axis points toward it. Other stars, such as those in the Big Dipper (Saptarishi), seem to move around the Pole Star due to Earth’s rotation.
Long-exposure photography even captures these movements as star trails.
🌏 Revolution of the Earth – Why Seasons Change
Apart from rotation, the Earth also moves around the Sun in a nearly circular path. This movement is called revolution.
The Earth takes 365 days and 6 hours to complete one revolution.
Two important factors create different seasons:
1. Tilt of the Earth’s Axis
The Earth’s axis is tilted at an angle of 23.5°.
This tilt stays the same as the Earth revolves around the Sun.
2. Spherical Shape of the Earth
Because of the curved shape:
- Sunlight falls more directly on some areas
- Sunlight spreads over a larger area in others
This causes different heating, leading to seasons.
🌞 What Happens in June?
- The Northern Hemisphere is tilted towards the Sun.
- Days are longer, sunlight is more direct, and it is summer.
❄️ What Happens in December?
- The Northern Hemisphere is tilted away from the Sun.
- Days are shorter, sunlight is less direct, and it is winter.
Seasons are opposite in the Southern Hemisphere.
☀️ Solstices and Equinoxes
21 June – Summer Solstice: Longest day in Northern Hemisphere
22 December – Winter Solstice: Shortest day in Northern Hemisphere
21 March & 23 September – Equinoxes: Equal day and night everywhere
🌙 Understanding Eclipses
🌑 Solar Eclipse
A solar eclipse occurs when the Moon comes between the Sun and the Earth.
Because the Moon, though much smaller, is close to the Earth, it can completely cover the Sun.
Types of Solar Eclipse:
- Total solar eclipse: Moon fully blocks the Sun
- Partial solar eclipse: Moon blocks only part of the Sun
⚠️ Never look at a solar eclipse with the naked eye—it can damage eyesight.
🌕 Lunar Eclipse
A lunar eclipse happens when the Earth comes between the Sun and the Moon and the Earth’s shadow falls on the Moon.
Types:
- Total lunar eclipse: Moon completely in Earth’s shadow
- Partial lunar eclipse: Only part of the Moon is covered
Lunar eclipses are safe to watch with the naked eye.
🌍 Why Earth’s Movement Is Important
Rotation → Day and Night
Revolution + Tilt → Seasons
Earth’s movement changes the night sky slowly over months
Eclipses occur due to the positions of the Sun, Earth, and Moon
This chapter beautifully connects our everyday observations—shadows, sunrise, sunset, seasons, eclipses—to the scientific movements of Earth and its moon.
~~~The End~~~
Chapter 12 Earth, Moon and the Sun
Download/Read PDF of NCERT Solution here:
*****
Watch the Chapter Explanation here:
*****
Watch the NCERT Solution Discussion here:
*For any kind of correction/removal please provide valid detail with link in comment section or contact us*
🔴Beware of Cyber-crime and cyber-fraudulent🔴
For any kind of query related to topics please comment.
.png)
0 Comments