Celestial Motions, Ep. 5: Solar Analemma

⚠️ Flash/Strobe warning ⚠️

Here’s another one you can do yourself, in real life! Take a picture of the sun every day at the exact same time from the same place. You’ll see its position in the sky at that time will change slowly throughout the year. This is due to the Earth’s tilt, it’s rotational speed, and the slightly elliptical nature of the Earth’s orbit around the sun.

If you superimpose all those images, like the simulation shown here, you will have what’s known as a solar analemma. Depending on what time of day, the shape will be rotated in the sky. In the morning, it lies on its side, whereas at noon, it will be straight up and down.

There are easier ways too, besides taking a picture every day. If you have a large window that faces the sun, just put a piece of tape on the glass where the sun is. Over the year, you will see this same infinity symbol shape emerge. (And it’s ok if you miss a few days due to weather - once a week is enough to see the shape.

Simulation Rendered with ‪@OpenSpaceProj‬
NYC Building Models provided by ‪@nycgov‬  DoITT

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