Chapter 1: Charting the Heavens Animation Archive

Click on the thumbnail or headline shown to open or to download the animation to your computer.

Earth's Seasons Movie

This 259K Quicktime animated clip is a simulation showing the annual variation of the angle of incidence of sunlight on Earth. The point of view for this clip is just above the terminator at 6:00 in the morning (Universal Time), just above Africa. Notice the variation in the angle of shadow along the surface of Earth. The Sun is at a right angle to this line. It is the variation in incidence angle of sunlight that causes the climate variations we perceive as seasons, and not the much smaller variation due to changes in the distance between Earth and the Sun throughout the year.

Planetary Motion Movies

These have been recorded to show the planets as viewed from a location in the central United States at the same local time every day. The time track for the moment shows standard (not daylight) local time. The reference time and orientation of the field of view is adjusted each month to show the morning and evening objects that you might observe. Notice the different time of morning brightening (or sunset fading) each day as the seasons progress. More on these topics in general can be found in Chapter 1 of the textbook.

• Movement of the ecliptic plane
  • Why is it tilted?
  • Where do the planets appear to rise (or set)?
• Apparent motion of the near-horizon planets
  • Which are visible on each horizon, and where?
  • Do you understand why?
  • Is there any retrograde motion?
• Apparent motion of the background stars
  • Why do the planets appear to move with respect to these stars?
  • Why, and in what direction, do the stars seem to move from night to night?

Movies just before sunrise and just after sunset for all months throughout the year have been included for completeness. To better understand the apparent motion of the ecliptic plane, check out the selections for a few months before and after the present month.

Solar Eclipse!

Solar Eclipse in Indiana

On May 10, 1994, the central United States was treated to a spectacular view of an annular solar eclipse. Although Bloomington was about 40 miles south of the path of annularity, the view was still impressive. This 0.3-MB MPEG clip was made by Indiana University from a set of images taken one minute apart using a solar telescope at their Kirkwood Observatory.

Source: Indiana University, Astronomy Animations, Image ID: Solar Eclipse

Solar eclipse viewed from space, in X rays

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