what is earth

Earth is the third planet from the Sun and the only known planet to support life. It is a rocky, terrestrial planet with a solid and active surface that includes mountains, valleys, canyons, and plains. About 70% of Earth's surface is covered by water, primarily oceans. Earth's atmosphere is mostly nitrogen with a significant amount of oxygen, which is essential for life. The planet has a dynamic climate system and geological processes due to its tectonic plates, and it is protected by a magnetosphere that shields it from harmful solar winds. Earth has one moon and is located in the Orion-Cygnus arm of the Milky Way galaxy. The planet formed about 4.5 billion years ago and continues to change through processes such as earthquakes, volcanic eruptions, and continental drift.