Overview - Introduction

This site is committed to providing as much information regrding the ellipse as possible - From definitions and properties to practical uses.

Many years ago I became interested in astronomy and in particular, the motion of the planets. I wanted to be able to predict the position of the planets at some future point in time. To do this, I had to become familiar with Kepler's Laws of planetary motion which is all based on the fact that planetary orbits are elliptical and not circular. More specifically, Kepler's second law states that a given planet's motion will "sweep out an area" relative to the sun (one of the elliptical focus points) that will be equal, for any given equal period of time. To solve this, I need to calculate the Area 'A', for any angle θ - See Figure 1 below. In solving for this area, it is given that other factors are "known" such as the distance to the sun from both the perihelion, and aphelion.

Figure 1