Why earth is called blue planet?

Earth is called the "blue planet" because of the blue color of the water that covers a significant portion of its surface. The blue color is due to the way that water absorbs and reflects different colors of light. Water absorbs colors at the red end of the spectrum, such as red and orange, while it reflects and scatters colors at the blue end of the spectrum. This is why the ocean appears blue when viewed from above. Additionally, the atmosphere of the earth also scatters blue light, which is why the sky appears blue as well. This combination of blue water and blue sky gives the Earth a distinct blue appearance when viewed from space.

Another reason Earth is referred to as the "blue planet" is because of the vast amount of water present on the planet. About 71% of the Earth's surface is covered by water, with the majority of it being in the form of oceans and seas. This vast expanse of water plays a critical role in regulating the planet's climate, as well as supporting a vast array of life forms.

Also, Earth's oceans are not just a source of water, but they also play a crucial role in the global climate system by absorbing and storing heat, moderating temperature, and transporting heat and moisture around the world. Oceans also help to regulate the amount of carbon dioxide in the atmosphere, which is important for controlling the Earth's temperature.

In addition, the ocean also plays a critical role in the water cycle, evaporating water from the surface and then releasing it as precipitation, which is important for maintaining life on land. The ocean also plays a crucial role in the nutrient cycle by absorbing and recycling nutrients, which are essential for the growth of plants and animals.

All these aspects mentioned above, makes Earth a unique blue planet.

In summary, Earth is called the "blue planet" because of the blue color of the water that covers a significant portion of its surface, the vast amount of water present on the planet, and the critical role it plays in regulating the planet's climate, supporting a vast array of life forms, and the nutrient and water cycle.