Why does earth not collide with sun

Kepler's law and Newtons laws explains this very well. So after the debris coagulated to form the earth, this initial orbital energy was retained. Hence the earth is moving on a stable orbit of fixed radius. Look up Kepler's laws, the period of revolution of a body squared is proportional to the distance between the sun and the body cubed. How does Earth keep its orbit around the Sun and not come closer to the Sun? Answer 1: The Earth is always being pulled towards the Sun by gravity.

Answer 2: Well, that's a good question, and Newton worried about the same thing! Answer 3: The Earth is "falling" around the Sun. Answer 4: Kepler's law and Newtons laws explains this very well. Click Here to return to the search form. Fortunately for us, the earth has a lot of sideways momentum.

Because of this sideways momentum, the earth is continually falling towards the sun and missing it. Scientists use fancy phrases for this effect such as "stable orbit" or "closed trajectory", but fundamentally what they mean is "falling and missing". All gravitational orbits are actually cases of falling and missing. Astronauts on the International Space Station are not in a no-gravity environment. They are surrounded by the earth's and the sun's immense gravity. More correctly, the astronauts are in a state of free fall.

Astronauts in orbit are constantly falling towards the earth and missing it. Newton had a clever way of explaining the nature of orbits. Consider a cannon on the surface of the earth that shoots a cannonball straight forward. As the ball speeds forward, earth's gravity pulls on it and it falls to the earth until it hits the ground. But the cannonball does not strike the earth at the exact spot it was fired because its forward momentum carries it forward a ways before striking the earth.

Now shoot the cannonball again, this time with a higher forward speed. The ball still falls and eventually strikes the earth, but because it has a higher forward speed sideways, relative to the earth the ball can cover more distance before striking the earth. If you shoot the ball fast enough, as shown in the picture on the right, it will still fall but will never manage to strike the earth. The earth will curve away faster than the ball can fall towards it.

Active 3 years, 2 months ago. Viewed 2k times. Improve this question. Mike G Mark ellon Mark ellon 2 2 bronze badges. In the roulette analogy the ball loses a lot of velocity due to friction and falls into the actual wheel, but in the case of the Earth, there's almost no friction and the mass is billions upon billions upon billions of times greater.

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