2objects is a simple HTML page that uses javascript to calculate the force of attraction, surface gravity, and density of two planetary objects. It also displays a scaled image of the two objects to help visuallize their distance from eachother. Inputs for mass of each object, diameter of each object, and the distance they are away from eachother. You can also zoom in and out.
This was created as an extra credit assignment for an astronomy class.
You can view the page here: 2objects