Dark Matter and Orbital Motion

Students make connections to the existence of dark matter with hands-on activities that illustrate how the orbits of objects are affected by the mass providing the centripetal force. The worksheets provide problems and activities for investigating orbital motion and the behaviour of dark matter candidate particles.



  • Lesson plans: Dark Matter and Orbital Motion
  • Videos: The Mystery of Dark Matter (approx. 30 min)
  • Activities: Key Concepts; Gravity and Orbital Motion (worksheets and solutions)
  • Supplementary Materials: Dark Matter in a Nutshell and more
  • Teacher-provided Materials: Stretchy fabric, ball, marbles

(Note: all lesson plans and worksheets provided as PDFs and modifiable MS Word documents)