The Analemma. By Bill Busler. Memphis Astronomical Society

The Analemma is usually seen as a "figure 8" on a globe of the Earth (somewhere in the Pacific Ocean), but what is its full astronomical significance?

In this talk, Bill Busler discusses how the analemma incorporates and reflects nearly every motion of the Earth: rotation, revolution, and precession, as well as the tilt of its axis and the eccentricity of its orbit. He shows how the analemma illustrates the 'Equation of Time', the difference between clock time and sundial time.

Bill concludes with a few brain teasers: What would the analemma look like if the Earth's orbit were circular? What if the Earth's axis were NOT tilted 23.5 degrees? How do the positions of perihelion and aphelion relative to the equinoxes and solstices affect the analemma? He takes us to the remote past and the distant future to find out. Finally, we see photographs of the analemma taken from various locations around the world.

From the September 8, 2017 Meeting of the Memphis Astronomical Society.

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