Image source [1]: Remnant of Kepler's Supernova SN 1604
Hello friends, this time I will talk a little about Kepler's laws in a simple and easy to understand way.
The laws of Kepler describe the movement of the planets in their orbit around the Sun, are three laws formulated by Johannes Kepler (German astronomer) in the early seventeenth century on the movement of the planets. These laws are based on data obtained by the Danish astronomer Tycho Brahe.
In astronomy, Kepler's laws of planetary motion are three scientific laws describing the motion of planets around the Sun. To better understand the previous description we will review some concepts related to the ellipse, with which we can understand what it means that the orbit of a planet is elliptical.
Parameters of an ellipsee: To describe an ellipse several parameters are used that give us information about how elongated the ellipse is and also whether it is elongated vertically or horizontally.
Major axis and minor axis: An ellipse has two axes, the major axis and the minor axis but, in mathematics it is more common to use the semiaxes, which correspond to half of the axes. The semimajor axis is a very important term.
Spotlights of an ellipse: An ellipse has two points called foci, which are on the major axis. Using the foci we will outline in a simple way the mathematical definition of an ellipse.
Eccentricity: To get an idea of how elongated an ellipse is, the term eccentricity is used. One of the ways to express eccentricity is:
Image source [2]: Kepler's first law placing the Sun at the focus of an elliptical orbit.
Kepler's Second Law: Kepler's second Law can be expressed as follows: The line that unites the Sun with a planet sweeps equal areas in equal times.
Image source [3]: The same (blue) area is swept out in a fixed time period. The green arrow is velocity. The purple arrow directed towards the Sun is the acceleration. The other two purple arrows are acceleration components parallel and perpendicular to the velocity.
Kepler's Third Law: This law expresses, by means of an equation, the relation that exists between the period of a planet around the Sun and the semimajor axis of its orbit.