🌍 Our Planet Earth
🔹 Introduction
Earth is the third planet from the Sun in our solar system. It is the only known planet that supports life. The air we breathe, the water we drink, and the land we live on — all are part of Earth. It is our home, and understanding how it works helps us take better care of it.
🔹 Basic Facts About Earth
- Shape: Earth is not a perfect sphere. It is slightly flattened at the poles and bulging at the equator. This shape is called an oblate spheroid.
- Size: Earth’s diameter is about 12,742 kilometers.
- Surface: Around 71% of Earth’s surface is covered with water, and the remaining 29% is land.
- Age: Earth is about 4.5 billion years old.
- Moon: Earth has one natural satellite — the Moon, which affects tides and stabilizes the planet’s rotation.
🔹 Layers of the Earth
Earth is made up of four main layers:
- Crust: The outermost layer where we live. It includes land and ocean floors.
- Mantle: Below the crust, this thick layer is made of semi-solid rock that moves slowly.
- Outer Core: A liquid layer made of iron and nickel. It helps create Earth’s magnetic field.
- Inner Core: The center of the Earth — a solid sphere of iron and nickel with very high temperatures.
🔹 Continents and Oceans
🌍 Continents (7 Total):
- Asia
- Africa
- North America
- South America
- Antarctica
- Europe
- Australia
🌊 Oceans (5 Total):
- Pacific Ocean
- Atlantic Ocean
- Indian Ocean
- Southern Ocean
- Arctic Ocean
🔹 Earth’s Atmosphere
Earth is surrounded by a layer of gases called the atmosphere, which protects us and allows life to exist.
Main Layers of Atmosphere:
- Troposphere: Closest to Earth, where weather happens.
- Stratosphere: Contains the ozone layer.
- Mesosphere: Where meteors burn up.
- Thermosphere: Has auroras and space shuttles orbit here.
- Exosphere: The outermost layer, merging into space.
Major Gases in Atmosphere:
- Nitrogen: 78%
- Oxygen: 21%
- Other gases: 1% (like carbon dioxide, argon, etc.)
🔹 Movements of the Earth
1. Rotation
- Earth spins on its axis.
- Takes 24 hours.
- Causes day and night.
2. Revolution
- Earth moves around the Sun.
- Takes 365.25 days (1 year).
- Causes seasons.
🔹 Natural Resources on Earth
Earth provides us with many resources we use every day.
Types:
- Renewable: Can be replaced (e.g., sunlight, wind, water).
- Non-renewable: Limited in quantity (e.g., coal, oil, minerals).
We must use resources wisely to protect the environment.
🔹 Life on Earth
Earth is the only known planet with liquid water, oxygen, and the right temperature for life.
Supports:
- Plants: Make oxygen through photosynthesis.
- Animals: Depend on plants and other animals for food.
- Humans: Use natural resources for shelter, food, and technology.
🔹 Environmental Issues
Human activities are affecting Earth in harmful ways.
Major Problems:
- Pollution: Air, water, and land pollution harm health and nature.
- Deforestation: Cutting down trees leads to habitat loss and climate change.
- Global Warming: Earth’s temperature is rising due to extra carbon dioxide.
- Plastic Waste: Plastics pollute oceans and harm animals.
What Can We Do?
- Save water and electricity
- Plant trees
- Recycle and reuse
- Avoid plastic bags
- Spread awareness
🔹 Fun Facts About Earth
- Earth is the only planet not named after a god.
- The Pacific Ocean is the largest ocean.
- Mount Everest is the highest point on land.
- The Mariana Trench is the deepest point in the ocean.
- Earth’s rotation is gradually slowing down — by about 1.7 milliseconds per century!
🧠 Conclusion
Our Earth is beautiful, complex, and full of life. From the tiniest insect to the tallest mountain, everything is connected. As students and future leaders, it’s our job to learn about Earth, respect nature, and protect our planet for future generations.
🖼️ Diagram: Layers of the Earth