On a clear night, look up at the sky. You can see thousands of tiny, twinkling lights. Those are stars! Our Sun is also a star -- the closest star to the Earth. It gives us light and heat.
The Sun, along with the eight planets, moons, and other objects that move around it, form the Solar System. The word "solar" comes from "Sol," which means Sun. Let us explore our solar family!
The Sun is a huge ball of hot, glowing gases. It is the largest object in our solar system. All the planets move around the Sun because of its strong pull (called gravity).
The Sun gives us light and heat, which makes life possible on Earth. Without the Sun, the Earth would be dark and freezing cold.
Think about it: The Sun is so far away that its light takes about 8 minutes to reach the Earth!
There are eight planets in our solar system. They all move around the Sun in fixed paths called orbits. Here is an easy way to remember their order:
My Very Educated Mother Just Served Us Noodles
| Planet | Position | Key Fact |
|---|---|---|
| Mercury | 1st (closest to Sun) | Smallest planet; very hot during the day |
| Venus | 2nd | Hottest planet; called the "morning star" or "evening star" |
| Earth | 3rd | Our home; only planet with life and liquid water |
| Mars | 4th | Called the "Red Planet" because of its reddish soil |
| Jupiter | 5th | Largest planet in the solar system |
| Saturn | 6th | Famous for its beautiful rings |
| Uranus | 7th | Tilts on its side; very cold |
| Neptune | 8th (farthest from Sun) | Very cold and windy; blue in colour |
Think about it: Earth is the only planet where we have found water in liquid form. That is why life exists here!
Rotation: The Earth spins on its own axis (an imaginary line from the North Pole to the South Pole). One complete spin takes about 24 hours (one day). The side facing the Sun has day, and the side away from the Sun has night.
Revolution: The Earth also moves around the Sun in its orbit. One complete trip around the Sun takes about 365 days (one year). This movement causes the change of seasons.
Think about it: When it is daytime in India, it is nighttime in America. This is because the Earth is round and keeps spinning!
The Moon is Earth's natural satellite. It moves around the Earth just as the Earth moves around the Sun. The Moon does not have its own light -- it reflects the light of the Sun.
The Moon takes about 28 days to go around the Earth once. As it moves, we see different shapes of the lit part. These shapes are called phases of the Moon.
After the full moon, the lit part slowly gets smaller again until the next new moon. In India, the full moon night is called Poornima and the new moon night is called Amavasya.
Stars are huge balls of hot gases that give out their own light and heat. They look tiny because they are very, very far away from us. During the day, we cannot see stars because the Sun's light is too bright.
A group of stars that forms a pattern in the sky is called a constellation. The Saptarishi (Ursa Major or Big Dipper) is a well-known constellation that looks like a large ladle.
| Word | Meaning |
|---|---|
| Solar System | The Sun and all the objects (planets, moons) that move around it |
| Star | A huge ball of hot gases that gives its own light and heat |
| Planet | A large body that moves around a star in a fixed path |
| Orbit | The fixed path along which a planet or moon moves |
| Rotation | The spinning of the Earth on its own axis (causes day and night) |
| Revolution | The movement of the Earth around the Sun (causes seasons and a year) |
| Satellite | An object that moves around a planet (the Moon is Earth's satellite) |
| Constellation | A group of stars forming a pattern in the sky |
When the Sun rises in Arunachal Pradesh (the easternmost state), people in Gujarat (the west) still see early morning light. As the Earth rotates, different parts of India face the Sun at slightly different times.
Many Indian festivals follow the Moon's phases. Karva Chauth is celebrated on a specific moon phase. Diwali falls on Amavasya (new moon night), and Holi is celebrated on Poornima (full moon night).
Ananya and her grandfather sit on the terrace in their village in Rajasthan. Away from city lights, they can see many stars. Her grandfather points out the Saptarishi constellation and the Pole Star (Dhruv Tara), which always stays in the north.
A. Fill in the Blanks
B. Multiple Choice Questions
C. Short Answer Questions
Observe the Moon every night for one week. Draw its shape and write the date. Notice how the shape changes!
| Day | Date | Draw the Moon's Shape |
|---|---|---|
| Day 1 | ||
| Day 2 | ||
| Day 3 | ||
| Day 4 | ||
| Day 5 | ||
| Day 6 | ||
| Day 7 |
Did the Moon's shape get bigger or smaller during the week? ____________________________