Physical Sciences 112 Earth-Moon-Sun Geometry Page

Want to know when the moon will be in the sky today?

The RED line is the local meridian of the observer (the Zenith-due South line you are familiar with from THExp#1).  On the right, your local meridian doesn't move, but on the left, you can see it sweeping past the sun and moon.

Click anywhere in the box to pause the animation, and then click in the box to restart.  You can advance the animation by 15 minute intervals, or by 24 hour intervals.  As in THExp #3, we've got a "polar" view here on the left, where the observer (you) is high above the north pole of the earth, the sun is far away to the right of the drawing, and provides the large, parallel rays of light that illuminate both the earth and the moon.  An earthbound observer is shown, with the extended horizon line, marked East and West.  As the earth rotates, the part of the sky the observer can see changes.  On the right is shown what the earthbound observer sees in the sky.  Feel free to use this program to help you understand what is required in THExp #3, and in the text Chapter 5, Section B.2.

The gray line is the local meridian of the observer (the Zenith-due South line you are familiar with from THExp#1).  On the right, your local meridian doesn't move, but on the left, you can see it sweeping past the sun and moon.

added link to test of WWWassign