The circumference of the Earth is: approximately 40075 kilometers

The Earth’s equatorial radius is 6378.137 kilometers, its polar radius is 6356.752 kilometers, its average radius is approximately 6371 kilometers, and its equatorial circumference is approximately 40075 kilometers Kilometers, it is an irregular ellipsoid with slightly flattened poles and slightly bulging equator.

The earth’s surface area is 510 million square kilometers, of which 71% is ocean and 29% is land. When viewed from space, the earth generally appears blue. The atmosphere is mainly composed of nitrogen and oxygen and a small amount of carbon dioxide, argon, etc.

The interior of the earth is divided into core, mantle, and crustal structures. The exterior of the earth's surface includes the hydrosphere, atmosphere, and magnetic field. The Earth is the only celestial body in the universe with known life and is home to millions of species of creatures, including humans.

The formation of the earth

The history of the earth is very long. According to radiocarbon dating measurements, the solar system was formed approximately 6.5±0.08 billion years ago, [8] while the proto-Earth was formed approximately 6.5±0.04 billion years ago. Theoretically, the formation of the sun began with the gravitational collapse of a huge cloud of hydrogen molecules 6.5 billion years ago. Most of the collapsed mass was concentrated in the center, forming the sun;

The rest of the sun was flattened while rotating, A protoplanetary disk formed, which in turn gave rise to planets, moons, asteroids, comets, meteoroids and other small solar system bodies.

The nebula hypothesis maintains that the planetesimals that formed the Earth originated from lumps with a diameter of one to ten kilometers that were left over from accretion collapse of gas, ice particles, and dust. After 10 to 20 million years of growth, these materials eventually formed the proto-Earth. The surface of the nascent Earth was an "ocean" composed of magma.

Reference for the above content: Baidu Encyclopedia-Earth