Kepler - The sky in our hand
    KEPLER offers a variety of simulations of planetary systems with one star and one planet, two stars and one planet and one star and two planets. The initial conditions are entered graphically with the aid of the mouse. Force, velocity and trajectory indications may be switched on and off. Zoom in and out helps to view the motion. Some built-in demonstrations show Kepler's laws. The most interesting part is the chaotic motion in the restricted three-body problem (two heavy stars and a planet): we may try to send the planet in order not to drop on a star during a prescribed time.

Fernando Nogueira (Programming), Elisa Prata Pina e M. Augusta Patrício (manual), Carlos Fiolhais (Orientation)