An **analemma** is a figure-eight pattern that shows the Sun's position in the sky at the same time each day over the course of a year, as seen from a fixed location on Earth. If you photographed the Sun at noon each day for a year from the same spot, these positions would trace out the analemma's shape. This shape results from two main factors: the Earth's axial tilt (23.5°) and the elliptical shape of Earth's orbit around the Sun. ![[Pasted image 20241108141754.png]] ### Why the Analemma Has a Figure-Eight Shape The Earth's axial tilt causes the Sun to appear higher or lower in the sky across the seasons, creating the vertical component of the analemma. Meanwhile, Earth's elliptical orbit means that Earth moves faster when it’s closer to the Sun (perihelion in early January) and slower when it’s farther away (aphelion in early July). This varying orbital speed shifts the Sun’s apparent east-west position slightly, forming the horizontal component of the figure-eight. ### How the Analemma Changes with Latitude The shape, orientation, and appearance of the analemma vary based on where you are on Earth: 1. **At the Equator (0° Latitude)**: - The analemma appears nearly symmetric vertically and horizontally, creating a balanced figure-eight. - The highest point of the analemma will be directly overhead, near zenith at noon during the equinoxes. - The figure-eight may appear tilted to the side, depending on the viewer’s direction. 2. **In Mid-Latitudes (e.g., 30°-60° Latitude)**: - The analemma is tilted, and the figure-eight is asymmetrical. - In the Northern Hemisphere, the upper loop (representing summer) is smaller than the lower loop (representing winter), because the Sun stays closer to the horizon in winter and reaches higher elevations in summer. - In the Southern Hemisphere, this orientation is reversed (the lower loop is smaller). 3. **Near the Poles (e.g., 66.5° and above)**: - The analemma becomes increasingly stretched horizontally because the Sun's altitude changes more slowly throughout the day. - At high latitudes, near the Arctic or Antarctic Circles, the Sun may disappear below the horizon for part of the year. During the polar night, an analemma may not form at all. - If an analemma is visible, it appears very low on the horizon, with one loop either significantly larger or not visible, depending on the season. 4. **At the Poles (90° Latitude)**: - The analemma would appear as a small, compressed line, tracing out a horizontal path. Here, the Sun does not rise and set daily but instead moves in a continuous circle around the horizon during the polar day or remains below the horizon during the polar night. - During the six-month daylight period, the analemma shifts side to side in a small, flat figure-eight as the Sun circles the horizon but stays at a consistent low altitude. ![[Pasted image 20241108142112.png]] In summary, **latitude affects the analemma's orientation, symmetry, and vertical stretch**. Near the equator, it’s symmetric and upright, while at mid-latitudes it becomes tilted and asymmetric. At high latitudes, the analemma is low on the horizon and horizontally stretched, and at the poles, it becomes a flat, side-to-side shift in the Sun's apparent position.