APOD: A Picturesque Equinox Sunset (2024 Mar 19)

[APOD Robot]

A Picturesque Equinox Sunset

Explanation: What's that at the end of the road? The Sun. Many towns have roads that run east-west, and on two days each year, the Sun rises and sets right down the middle. Today, in some parts of the world (tomorrow in others), is one of those days: an equinox. Not only is this a day of equal night ("aequus"-"nox") and day time, but also a day when the sun rises precisely to the east and sets due west. Displayed here is a picturesque rural road in Alberta, Canada that runs approximately east-west. The featured image was taken during the September Equinox of 2021, but the geometry remains the same every year. In many cultures, this March equinox is taken to be the first day of a season, typically spring in Earth's northern hemisphere, and autumn in the south. Does your favorite street run east-west? Tonight, at sunset, you can find out with a quick glance.

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[Roy]

Lovely picture, lots of livestock out in the field of the nearer farmstead. Alberta foodstuffs sustain a great deal of Canada and the USA.

[Avalon]

The March and September equinoxes posed special hazards for me on local east/west running roads. Some evenings I could not see ahead of me as the sun was so very bright and seemingly setting right on the roadway as I was making my way home from work. In one instance I recall having to pull over and wait a few minutes because I could not see over the slight hill ahead of me and could have collided with any oncoming traffic. Thankfully, this condition does not last forever!

[Peter87]

Very impressive photograph, both aesthetically and conceptually. My question is, the sun is observable and approximately the same shade of orange is observable both on the horizon and on the cloud above, but the moment the sun is below the horizon, most likely the horizon will remain orange color for some time while the cloud will likely change to purple. What accounts for the dual (and more) colors of the sky at that point?