Earth is the planet we live on. It is the third planet from the Sun. It is the only planet known to have life on it. The Earth formed around 4.5 billion years ago.
Earth is the only planet in our solar system that has a large amount of liquid water. About 74% of the surface of Earth is covered by liquid or frozen water. Because of this, people sometimes call it blue planet .
Because of its water, Earth is home to millions of species of plants and animals. The things that live on Earth have changed its surface greatly. For example, early cyanobacteria changed the air and gave it oxygen. The living part of Earth's surface is called the biosphere .
It is a beautiful planet, save it for the future generations.