User:Oxana Smacheluk/TWA/Earth





=Earth= The Earth is the third planet from the Sun. It is one of the four terrestrial planets in our Solar System. This means most of its mass is solid. The other three are Mercury, Mars, and Venus. The Earth is also called the Blue Planet, Planet Earth, and Terra.

The Earth formed around 4.5 billion years ago. It is home to millions of species of plants and animals, including humans.

Earth is the only planet known to have life on it. It has both cold and hot areas but most of them can be used for living. The organisms that live on Earth have completely changed its air (atmosphere); this is called a biosphere. 71% of Earth's surface is covered in salt water oceans. Earth is the only place in the Solar System where liquid water is known to exist at present. The other 29% of the Earth's surface is made of rocky land in the shape of continents and islands.


 * Earth interacts with other objects in the Solar System, particularly the Sun and the Moon. The Earth orbits or goes around the Sun once every 365.25 days. One spin is called a day and one orbit around the Sun is called a year. This explains why there are 365 days in a year, but a leap day is added once every 4 years.