The aim of this app is to model the orbital relationship between the Earth and the Sun that results in what we see as relative solar motion. You can use the buttons located in the top-left to switch between geo-centric (where the Earth is the view focus) and helio-centric (where the Sun is the view focus), as well as selecting various useful dates and times. The button group in the bottom-left corner allow you to toggle the overlay of information useful for understanding the various characteristics of the relationship.
