Why Are Planetary Orbits Elliptical?

Thread starter SandeshPhy
Start date Jan 19, 2011
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Orbits Planets Shape

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Planetary orbits are elliptical due to the gravitational forces acting between the planets and the sun, as described by Newton's law of universal gravitation. Kepler's first law states that planets move in ellipses with the sun at one focus, which can be derived mathematically from Newton's laws of motion. The elliptical shape arises because the gravitational force provides a centripetal acceleration that varies with distance, leading to non-circular paths. The discussion emphasizes the mathematical relationship between these laws, illustrating how they explain the observed orbital shapes. Understanding these principles is crucial for comprehending planetary motion and celestial mechanics.

Jan 19, 2011

SandeshPhy

Why are the orbits of planets revolving around a body(say the sun) elliptical rather than circular or any other shape?
Please show the answer mathematically.

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Jan 19, 2011

phyzguy

Science Advisor

This page shows how Kepler's laws(including Kepler's first law that planetary orbits are ellipses) follow from Newton's laws of motion and Newton's law of universal gravitation.

http://en.wikipedia.org/wiki/Keplers_laws

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