This is something I developed as part of my A-Level COMP4 Computing Project. It was developed in C# using the XNA game engine. It is an interactive implementation of Newton's Universal Law of Gravitation, allowing the user to simulate a solar system including planets and comets. It also simulates the two tails formed by comets during their orbit around a star.
I also built my own user interface as shown below. It wasn't the neatest thing in the world but it was my first experience with object oriented software design.
