What is the earth like? (picture)

Earth Earth is one of the eight planets in the solar system, internationally known as "Gaia" (Gaia, the god of the earth in Greek mythology, is a highly respected and prominent god among the gods. Is the earliest god in Greek mythology, born from the chaos at the beginning of the world. She is Zeus' grandmother. Gaia gave birth to Uranus, the god of the sky, and combined with him gave birth to six men and six women, twelve Titan, three Cyclops and three centimani. This is the beginning of the world, and all the gods are her descendants. Until now, westerners still often refer to the earth as Gaia. ), according to the order from near to far from the sun, is the third. It has a natural satellite-the moon, forming a celestial system-the earth-moon system. The earth rotates from west to east and revolves around the sun at the same time. The combination of the earth's rotation and revolution has produced the alternation of day and night and seasonal changes on the earth (the speed of the earth's rotation and revolution is uneven). At the same time, due to the gravity of the sun, the moon and nearby planets, as well as the influence of many factors such as the earth's atmosphere, ocean and materials inside the earth, the direction of the earth's rotation axis will change in space and the earth itself. The inertial centrifugal force produced by the earth's rotation makes the spherical earth gradually expand from the poles to the equator, becoming a slightly flat ellipsoid of revolution at present, and the polar radius is about 2 1 km shorter than the equatorial radius. Apollo spacecraft saw on the moon that the earth was composed of a series of concentric layers. The earth has a core (core), mantle (mantle) and crust (crust) structure. There are hydrosphere, atmosphere and magnetosphere outside the earth, forming a beautiful coat around the solid earth. As a planet, the earth was born in the primitive solar nebula 5.6 billion years ago. Basic parameters of the earth: oblateness factor: 298.257; average density: 5.52g/ Cm3; equatorial radius: ae = 6378 136.49 m; polar radius: ap = 6356755.00 m; average radius: A = 6371001.00.