#### Kepler’s 3rd law equation

## What is Kepler’s 3rd law?

Kepler’s 3rd Law. (3) The square of the orbital period of a planet is proportional. to the cube of the mean distance from the Sun. (also stated as– of the “semi-major axis” of the orbital ellipse, half the sum of smallest and greatest distances from the Sun)

## What is the formula for Kepler’s 3rd law of planetary motion?

Kepler’s Third Law T=2π√r3GME. For an ellipse, recall that the semi-major axis is one-half the sum of the perihelion and the aphelion. For a circular orbit, the semi-major axis (a) is the same as the radius for the orbit.

## What is Newton version of Kepler 3rd law?

Newton’s generalized form of Kepler’s 3rd law gives us a way to measure masses from orbital motions! For exampl, we can derive the mass of the Sun by using the period and size of the Earth’s orbit: P_{earth} = 1 year = 3.156 x 10^{7} seconds. a_{earth} = 1 AU = 1.496 x 10^{11} meters.

## What is an example of Kepler’s third law?

Use these examples to determine if you are using Kepler’s Third Law correctly: – An asteroid orbits the sun at a distance of 2.7 AU. – A dwarf planet discovered out beyond the orbit of Pluto is known to have an orbital period of 619.36 years.

## Why are Kepler’s three laws important?

Kepler’s laws describe how planets (and asteroids and comets) orbit the sun. They can also be used to describe how moons orbit around a planet. But, they do not just apply to our solar system — they can be used to describe the orbits of any exoplanet around any star.