User:5mv2/TWA/Earth





=Earth= The Earth is the third planet from the Sun, with a semimajor axis of about 1 AU. It is one of the four terrestrial planets in our Solar System. This means they have a "solid planetary surface" (Terrestrial planet, check your sources, TWA!). 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 observable universe which is known to support life. Earth has many places that are suitable for humans inhabitation; although, some areas of the planet can be dangerous for humans or uninhabitable.

Science shows that Earth formed around 4.5 billion years ago. 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. Until a few months ago, Earth was believed to be the only place in the Solar System where liquid water existed. The other 29% of its 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 (due to its high mass) and the Moon (due to its proximity). The Earth orbits the Sun roughly once every 365.25 days, while rotating around its own axis. One spin around that is called a day and one orbit around the Sun is called a year. This is why there are 365 days in a year, but a leap day added to the calendar once every 4 years.