Earth means:
In astronomy mythology, her Greek name was Gaea. Earth was the mother of the mountains, valleys, streams and all other land formations. She was married to Uranus

How Big is the Earth?
The Earth is the biggest of all the terrestrial planets. A terrestrial planet is a dense planet found in the inner Solar System. The diameter of Earth is 7,926 miles. The circumference measured around the equator is 24,901 miles. There are currently almost 7 billion people living on the Earth. About 30% of the Earth’s surface is covered with land, while about 70% is covered by oceans.

The Planet
Our planet is  an oasis of life in an otherwise desolate universe.  The Earth’s temperature, weather, atmosphere and many other factors are just right to keep us alive.

To learn more about Earth, read these articles.

Moons:
The Earth has one moon.  Its name is Luna.