Analemma explanations and simulations
- https://mtirado.com/resources/analemma-calc/index.html
- https://mtirado.com/blog/demystifying-the-analemma/
- https://www.geogebra.org/m/jv4knafm (Geogebra)
- https://alokm.com/astro/analemmagenerator.html# (all planets)
- http://andrewmarsh.com/apps/staging/sunpath3d.html (3d path of the sun across celestial sphere)