Question

why earth rotates around itself and how

Answer 1

rotation is the word of earth rotating around itself about an orbit imagined by us

Answer 2

Earth's Rotation. The earth rotates about an imaginary line that passes through the North and South Poles of the planet. This line is called the axis of rotation. Earth rotates about this axis once each day . in any gravitationally bound system, BOTH objects are orbiting EACH OTHER. The difference in masses drives everything; the more massive body moves less, while the less massive body moves more. The Earth and Moon orbit each other, but the difference in mass - the Moon is about 1/6th the Earth's mass - means that the Moon orbits the Earth much more than the reverse. 

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