Click to move masses, sliders to change mass Orange is the barycenter The Barycenter is the point where two masses orbit or whatever agh try again, from wikipedia The Barycenter is the point between two objects where they balance each other. For example, it is the center of mass where two or more planets orbit each other. When a moon orbits a planet, or a planet orbits a star, both bodies are actually orbiting around a point that lies outside the center of the larger body.
Me The trick is using weighted averages This is also what they use to make lens flare I think