User:Sotoagustina/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 is home to millions of species of plants and animals, including humans.

Earth is the only planet in the galaxy known to harbor life. Earth has many places that are suitable for humans to live; although, some areas of the planet can be dangerous for humans or uninhabitable. Science shows that Earth was formed about 4.5 billion years ago. The organisms that live on Earth have completely changed its air (atmosphere); this is called the biosphere. 71% of the Earth's surface is covered by oceans of salt water. Earth is the only place in the Solar System where liquid water is known to exist today. The remaining 29% is made up of rocky terrain in the form of continents and islands. Earth interacts with other objects in the Solar System, particularly the Sun and the Moon. The Earth orbits the Sun approximately once every 365.25 days. A spin is called a day and an orbit around the Sun is called a year. That is why there are 365 days in a year, but a leap day is added to the calendar once every 4 years.