Earth information 50 words

Earth is one of the eight planets in the solar system, ranking third in the order from near to far from the sun. It has a natural satellite-the moon, forming a celestial system-the earth-moon system. As a planet, the earth originated from the primitive solar nebula 4.6 billion years ago. The earth will interact with other celestial bodies in outer space, including the sun and the moon. The earth is the home of millions of creatures, including human beings, and the only celestial body in the universe where life is known. The equatorial radius of the earth is 6378. 137㎞, the average equatorial radius is about 637 1㎞, the polar radius is 6356.752㎞, and the equatorial circumference is 40075.7㎞. On the earth, it is 7/kloc-0. The earth is the only planet found so far where human beings live.