My Solar System is an orbital simulator which students use to investigate how mass, position and velocity affect gravitational forces. Students can either select from ten preset scenarios, ranging from simple sun-planet-moon simulations to more complex situations such as Trojan asteroids or Four Star ballet, or they can create their own scenarios by selecting and dragging symbols into position. An additional option is available: users can decide whether or not to have system centered movement. When the simulation is run with this option disabled (unchecked), students will see that all objects are in motion. The creators note a few limitations of their model. First, the simulation lacks force vectors. Next, units of mass are not specified and, finally, objects’ masses should not exceed several thousand units. Note: students can either run the simulation from the webpage or can download the file. Java is required. Additional Teacher Resources are available if users register for a free account. Although this simulator can be used in both middle and high school classrooms, this review reflects middle school Performance Expectations.