As a child we learned "the Sun rises in the east and sets in the west," right? Not always. In fact that's true only two days a year -- the equinoxes (March and September).
The Motions of the Sun Simulator was used to show the apparent motion of the Sun across the sky on the June Solstice. Notice the Sun rises along the northeastern horizon and sets along the northwestern horizon. At Washington, D.C. (38.89° North latitude and 77.03° degrees West longitude) the Sun reaches a maximum altitude of 74.7° above the horizon, the highest maximum altitude all year.
 |
| "Motions of the Sun Simulator" set for 21 JUN at 38.8 N latitude. |
The following animation shows the Sun's apparent path across the sky on the June Solstice, repeated several times.
Firsthand observations
I used my iPad mini 6 running the "Theodolite" iOS app to take a time series of images during the evening on 21 June 2026, beginning at 8:00 PM and ending at 8:36 PM (sunset) with an interval of five minutes between shots. The camera was mounted on a tripod facing exactly west. Notice how far north of west the Sun sets.
 |
| 21 JUN 2026 | 8:00 PM | Facing west. |
 |
| 21 JUN 2026 | 8:05 PM | Facing west. |
 |
| 21 JUN 2026 | 8:10 PM Facing west. |
 |
| 21 JUN 2026| 8:15 PM | Facing west. |
 |
| 21 JUN 2026 | 8:20 PM | Facing west. |
 |
| 21 JUN 2026 | 8:25 PM | Facing west. |
 |
| 21 JUN 2026 | 8:30 PM | Facing west. |
 |
| 21 JUN 2026 | 8:36 PM | Facing west. |
The exact position of sunset was obscured by both clouds and the tree line to the west of my vantage point, but it's clear enough the Sun set near the trunk of the tallest tree along the horizon.
By the way, I have no idea what the white orb is that appears in the lower-right corner of most of the sunset images. I assume it's a feature of the "Theodolite" app, but I'm not sure.
Related Resource: Theodolite - a blog post by Walter Sanford
Copyright © 2026 by Walter Sanford. All rights reserved.
No comments:
Post a Comment
Comments are invited and wlecome.