This web page contains an activity to track the position of the sun at different times during the year. Participants create their own sundials and mark the location of the sun’s shadow over a period of time. An...

This simple animation illustrates how we observe the phases of Venus. As the planet revolves around the Sun, there are times of the year when it is observed completely lit up by the star and times when we only get it's...

Authored and curated by David P. Stern, these pages explore orbits and the "Lagrangian points", where objects will orbit the sun with the same period as the earth. This has applications for solar monitoring spacecraft....

This applet shows from three different physical perspectives the orbit of a low-mass test particle around a non-rotating black hole. Below the applet is an instructional guide to the applet and a description of the...

This geometry lesson from Illuminations uses the model of the orbits of Mars and Earth relative to the sun to illustrate parametric equations. As an interdisciplinary learning activity, the material may be used in...

This case study uses the example of Pluto: how do we determine what a planet is? The lesson compares orbital parameters like semi-major axis, orbital period and orbital resonance of different planets. The material would...