Newton 2D for Windows

This freeware program presents a moving graphical simulation of a system of up to ten bodies that obey Newton's laws in a two-dimensional universe.  You can get a feel for orbital mechanics, watch Jupiter perturb the orbit of an asteroid, design your own planetary systems, and spend many hours watching the evolution of multi-body systems.

Screen Shot of Application
One Hypothetical System

The mass, velocity and position of up to ten objects can be specified individually.  A rudimentary circular orbit calculator aids in the preliminary setup of a universe.

Screen Shot of Application
The Object Editor

The observer's point of view can be moved, rotated, zoomed and locked to any object.  Simulations may be saved and recalled.

This application is free for non-commercial use and distribution.  See the "Obtaining and Distributing" section of the help file.  The current distribution package is here.