In order to understand the orbits of planets, comets, and other celestial bodies, it is necessary to examine the principles of how gravity and the velocity of an object interact to produce an orbit. It is a common misconception among students that planetary orbits are circular.

This practical activity gives a space setting to speed-time graphs. It shows how the speed of objects in elliptical orbits change as they orbit the Sun. An extension activity which looks at the geometry of ellipses and their relation to physical parameters in the Solar System is included.

  • Marble-ous ellipses - classroom demonstration video, VP02
  • Released 30/07/2014
  • Length 00:04:06
  • Language English
  • Footage Type Documentary
  • Copyright ESA


If you'd like to find out more about engaging workshops and demonstrations at the National Space Centre or your School, see our Student Masterclasses.