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How the earth and other planets are circling around the sun, and why they are not going away from it?
Question Date: 2013-05-20
Answer 1:

Thanks for your interesting question! All of the planets in our solar system (the Earth included) orbit the sun in an elliptical path - an ellipse is a stretched circle, see the following page for more information:


The planets stay along this path - instead of getting either closer to or further from the sun - because each of the planets are predominantly acted on by two forces that exactly oppose and balance one another:

• The gravitational attraction between the sun and each of the planets pulls the planets towards the sun

• The rotational motion of the planets around the sun leads to a force that pushes the planet away from the sun

A good analogy for this motion is a tennis ball that is attached to a string and swung in a circle around you. When the ball first starts swinging, the motion drives the tennis ball away from you until the string gets tight. Once the string gets tight, the tennis ball is "pulled" into a circular path, which is similar to the way the sun's gravitational force keeps the planets moving in an elliptical path. You may also wish to check out the following webpage for a diagram of these forces and directions:

what causes an orbit

I hope that this helps!

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