# State Kepler's law of plentary motion.

## Question:

State Kepler's law of plentary motion.

## Kepler's Laws of Planetary Motion:

The Kepler's laws are used to describe the orbit of planets and these laws are used in various missions by the astronomers to find the exoplanets as well as to discover data about the planets.

The Kepler's three laws of planetary motion are used to describe the motion of the planets around the sun and thus helps to explore various exoplanets also. The three Laws of Kepler planetary motion are:-

Kepler's First Law- The path that is followed by all the planets to rotate around the sun is elliptical and the sun is the focus of the ellipse.

Kepler's Second Law- The planet closest to the sun will move faster and this law helps to determine the speed of a planet in the orbit.

Kepler's Third Law-The relationship between the time period and the distance between the planets and the sun is given by the Kepler's third law of planetary motion. The distance of the planet from the sun can describe the time that a planet requires to complete one revolution of the sun and it can be written as,

{eq}T^{2}\ \alpha \ r^{3} {/eq}

• T is the time period of the planets in years
• r is the semimajor axis in astronomical units. 