1. The earth is the third planet in the solar system from within and outside, as well as the planets with the largest diameter, mass and density in the solar system, and is the sole home of humankind. Humans living on the planet often call it the world。
2. The earth is also a “terraform”. The third planet in the solar system, near the sun, is slightly flat in shape, and the equator is a three-axis elliptical sphere. The atmosphere is surrounded by land and sea on the surface, with humans, flora and fauna and micro-organisms。
Resources such as the earth's minerals and organisms sustain the global population. Humankind on earth is divided into some 200 independent sovereign countries and territories that are interlinked through diplomacy, tourism, trade and war. Human civilization has had many views on this planet, including the creation of man by god, the circle, the earth as the center of the universe。
4. The term "mother of the earth" means "geia," as is often the case in the west。
The earth is home to millions of organisms. Including human beings. The earth is the only living object in the universe known to mankind today. Since the birth of the earth 4. 5 billion years ago and after the birth of life, the earth's biosphere has changed the atmosphere and other environments, allowing oxygen-intensive organisms to be born and the atmosphere to be formed. Together with the earth's magnetic field, the atmosphere blocks harmful rays from the universe and protects life on land. The physical properties of the earth and its geological history and orbits perpetuate life on earth cyclically. The earth is expected to continue to live for 1. 5 billion years until the increasing brightness of the sun destroys the biosphere on earth。
6. The earth interacts with other celestial bodies in outer space, including the sun and the moon. Currently, one week around the sun takes 366, 26 times more time than the rotation, which is called a star year, equivalent to 365, 26 sun days. The earth's axis is tilted 23, 4° (orbital plane leaning 23, 4°) resulting in seasonal changes on the surface of the planet with a periodicity of 1 star year. The moon is the only natural satellite born 4. 5, 300 million years ago, creating a tidal phenomenon on earth, stabilizing the tip of the axis and slowing the rotation of the earth。
Some 3. 8 to 4. 1 billion years ago, the impact of asteroids in the late bombing period significantly changed the surface environment。
8. The earth's surface is divided into hard parts, or called plates, which move on the earth's surface in a geological age cycle. About 71 per cent of the earth's surface is ocean, with the remainder divided into continents and islands. Liquid water is necessary for all known life, but does not exist on the surface of all other planets. The earth's interior remains very active, with a thick mantle, a liquid outer core and a solid iron inner core。
