The Ecliptic

[Play/Download Movie (5 MB)]

This movie shows the Sun moving around the celestial sphere over the course of the year. It traces that motion out as the ecliptic, and zooms in to show where the Sun would appear on the solstices and the equinoxes. This movie shows the "full" celestial sphere model, where the Sun is just one more object on the surface of the celestial sphere.

This movie is probably best used in conjunction with The Sun's Position on the Celestial Sphere. It's important for students to realize that the celestial sphere model is a useful fiction we create to help us easily predict where we will see things in the sky. The last thing we want is for students to take this model and come away thinking that their astronomy professor said that the Sun is really going around the Earth!

As with many of my movies, there is no narration or sound. It's designed to be used by a lecturer, who will pause it at opportune places to discuss it or ask questions of students.

This work is licensed under a Creative Commons License.

Earth texture by Rick Kohrs.

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