Earth

Earth is a planet inhabited by Humans and multiple alien races. It is the third planet from the Sun and it is one of the few planets known to harbor intelligent life. According to various studies, the Earth was formed over 4.5 billion years ago. The Earth holds 1 natural satellite.

Earth's axis of rotation is tilted with respect to its orbital plane, producing seasons on Earth. The gravitational interaction between Earth and the Moon causes tides, stabilizes Earth's orientation on its axis, and gradually slows its rotation. Earth is the densest planet in the Solar System and the largest and most massive of the four rocky planets.

Earth's outer layer (lithosphere) is divided into several rigid tectonic plates that migrate across the surface over many millions of years. About 29% of Earth's surface is land consisting of continents and islands. The remaining 71% is covered with water, mostly by oceans but also lakes, rivers and other fresh water, which all together constitute the hydrosphere. The majority of Earth's polar regions are covered in ice, including the Antarctic ice sheet and the sea ice of the Arctic ice pack. Earth's interior remains active with a solid iron inner core, a liquid outer core that generates Earth's magnetic field, and a convecting mantle that drives plate tectonics.

Politically, Earth is divided into dozens of political states called sovereign states. Compared to other planets like Beto-XG and Proteus, Earth is an extremely divided planet. Historically, the planet has been undergoing a conflict called the Great Cold War for centuries.

Etymology
The modern English word Earth developed from a wide variety of Middle English forms, which derived from an Old English noun most often spelled eorðe.

Originally, earth was written in lowercase, and from early Middle English, its definite sense as "the globe" was expressed as the earth. By Early Modern English, many nouns were capitalized, and the earth became (and often remained) the Earth, particularly when referenced along with other heavenly bodies.