APOD: A Picturesque Equinox Sunset (2022 Mar 20)

Comments and questions about the APOD on the main view screen.
Post Reply
User avatar
APOD Robot
Otto Posterman
Posts: 5345
Joined: Fri Dec 04, 2009 3:27 am
Contact:

APOD: A Picturesque Equinox Sunset (2022 Mar 20)

Post by APOD Robot » Sun Mar 20, 2022 4:07 am

Image 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 is one of those days: an equinox. Not only is today 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. Featured here is a picturesque road in northwest Illinois, USA that runs approximately east -west. The image was taken during the March Equinox of 2015, and shows the Sun down the road at sunset. 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.

<< Previous APOD This Day in APOD Next APOD >>

heehaw

Re: APOD: A Picturesque Equinox Sunset (2022 Mar 20)

Post by heehaw » Sun Mar 20, 2022 9:52 am

Sun in your eyes! Driving danger! If only road grids had been laid out NE to SW!

stargeezer2233

Re: APOD: A Picturesque Equinox Sunset (2022 Mar 20)

Post by stargeezer2233 » Sun Mar 20, 2022 1:04 pm

I was not expecting to see Roland Christen of Astro-Physics as the photographer. Who knew he has other interests besides making fine APO telescopes?

Guest

Re: APOD: A Picturesque Equinox Sunset (2022 Mar 20)

Post by Guest » Sun Mar 20, 2022 1:31 pm

Actually the day of the equinox does not result in equal lengths for day and night. In theory is should but because of refraction by the Earth's atmosphere, the Sun is above the horizon for several minutes longer.

User avatar
Chris Peterson
Abominable Snowman
Posts: 18113
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA
Contact:

Re: APOD: A Picturesque Equinox Sunset (2022 Mar 20)

Post by Chris Peterson » Sun Mar 20, 2022 1:53 pm

Guest wrote: Sun Mar 20, 2022 1:31 pm Actually the day of the equinox does not result in equal lengths for day and night. In theory is should but because of refraction by the Earth's atmosphere, the Sun is above the horizon for several minutes longer.
Depends on how you define "day" and "night".

The geometry is easily understood in terms of a point-source sun and a planet with no atmosphere.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
https://www.cloudbait.com

De58te
Commander
Posts: 583
Joined: Mon Sep 30, 2013 6:35 pm

Re: APOD: A Picturesque Equinox Sunset (2022 Mar 20)

Post by De58te » Sun Mar 20, 2022 2:04 pm

Actually I don't really like roads that run exactly east west. I prefer east west roads that are angled some 15 to 20 degrees northwest or southwest. Vice versa the other way for northeast and southeast. That way I don't get the sun in the eyes. It's okay right at sunset as pictured but it is unbearable driving 15 minutes to 30 minutes earlier. I found a solution for driving those due west and east roads though. If you can swing it, drive those roads at high noon, or even wait 15 minutes after sunset or before sunrise to drive. Of course I pity those that can't swing it, like bus drivers, taxi drivers, or pizza deliverers!

User avatar
Chris Peterson
Abominable Snowman
Posts: 18113
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA
Contact:

Re: APOD: A Picturesque Equinox Sunset (2022 Mar 20)

Post by Chris Peterson » Sun Mar 20, 2022 2:05 pm

heehaw wrote: Sun Mar 20, 2022 9:52 am Sun in your eyes! Driving danger! If only road grids had been laid out NE to SW!
That still leaves a good chunk of people living in Earth's temperate zones driving into the Sun. It just shifts the bad dates to near the solstices.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
https://www.cloudbait.com

User avatar
Chris Peterson
Abominable Snowman
Posts: 18113
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA
Contact:

Re: APOD: A Picturesque Equinox Sunset (2022 Mar 20)

Post by Chris Peterson » Sun Mar 20, 2022 2:06 pm

De58te wrote: Sun Mar 20, 2022 2:04 pm Actually I don't really like roads that run exactly east west. I prefer east west roads that are angled some 15 to 20 degrees northwest or southwest. Vice versa the other way for northeast and southeast. That way I don't get the sun in the eyes. It's okay right at sunset as pictured but it is unbearable driving 15 minutes to 30 minutes earlier. I found a solution for driving those due west and east roads though. If you can swing it, drive those roads at high noon, or even wait 15 minutes after sunset or before sunrise to drive. Of course I pity those that can't swing it, like bus drivers, taxi drivers, or pizza deliverers!
All that does is change the dates when you are driving straight into the Sun.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
https://www.cloudbait.com

User avatar
Fred the Cat
Theoretic Apothekitty
Posts: 958
Joined: Mon Feb 22, 2016 4:09 pm
AKA: Ron
Location: Eagle, Idaho

Re: APOD: A Picturesque Equinox Sunset (2022 Mar 20)

Post by Fred the Cat » Sun Mar 20, 2022 2:16 pm

Spring showers bring rainbows too. :ssmile:
IMG_4045 (2).JPG
Flowers soon to follow! :thumb_up:
Freddy's Felicity "Only ascertain as a cat box survivor"

User avatar
johnnydeep
Commodore
Posts: 2781
Joined: Sun Feb 20, 2011 8:57 pm

Re: APOD: A Picturesque Equinox Sunset (2022 Mar 20)

Post by johnnydeep » Sun Mar 20, 2022 4:26 pm

Chris Peterson wrote: Sun Mar 20, 2022 1:53 pm
Guest wrote: Sun Mar 20, 2022 1:31 pm Actually the day of the equinox does not result in equal lengths for day and night. In theory is should but because of refraction by the Earth's atmosphere, the Sun is above the horizon for several minutes longer.
Depends on how you define "day" and "night".

The geometry is easily understood in terms of a point-source sun and a planet with no atmosphere.
Apparently, there is also the "equilux". But is 'equilux' an officially recognized term? I didn't know it existed until a few days ago. See https://ourplnt.com/equilux-equinox/, which has a helpful video explaining both terms:

Click to play embedded YouTube video.
--
"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."{ʲₒʰₙNYᵈₑᵉₚ}

User avatar
Cousin Ricky
Science Officer
Posts: 445
Joined: Mon Aug 26, 2013 4:08 pm
Location: St. Thomas, U.S. Virgin Islands (+18.3, -64.9)

Re: APOD: A Picturesque Equinox Sunset (2022 Mar 20)

Post by Cousin Ricky » Sun Mar 20, 2022 5:01 pm

I was in northeastern Illinois during last September’s equinox. While I was riding the El near sunset, it occurred to me that it was the day after the equinox, and Chicago’s streets are laid out NS and EW, and sure enough, I got to see Chicagohenge.

The only place I’ve ever lived with a NS-EW grid is Gainesville, Florida, but at the time I had an inaccurate understanding of how the Sun moves from our frame of reference, so checking the Sun on the equinox wasn’t a concept to me.

I also lived in Boston, Massachusetts for a time, which does have one neighborhood laid out EW, but I had been advised to stay out of that neighborhood due to the color of my skin. (“Sundown towns” aren’t just in the USA South.) I did not learn about the nearby MIT Infinite Corridor until I moved away, but MIThenge isn’t equinox-aligned anyway.

User avatar
Cousin Ricky
Science Officer
Posts: 445
Joined: Mon Aug 26, 2013 4:08 pm
Location: St. Thomas, U.S. Virgin Islands (+18.3, -64.9)

Re: APOD: A Picturesque Equinox Sunset (2022 Mar 20)

Post by Cousin Ricky » Sun Mar 20, 2022 5:15 pm

Chris Peterson wrote: Sun Mar 20, 2022 2:06 pm
De58te wrote: Sun Mar 20, 2022 2:04 pm Actually I don't really like roads that run exactly east west. I prefer east west roads that are angled some 15 to 20 degrees northwest or southwest. Vice versa the other way for northeast and southeast. That way I don't get the sun in the eyes. It's okay right at sunset as pictured but it is unbearable driving 15 minutes to 30 minutes earlier. I found a solution for driving those due west and east roads though. If you can swing it, drive those roads at high noon, or even wait 15 minutes after sunset or before sunrise to drive. Of course I pity those that can't swing it, like bus drivers, taxi drivers, or pizza deliverers!
All that does is change the dates when you are driving straight into the Sun.
Very true. For example, on Memorial Drive in Cambridge, Massachusetts, the sunset dates are more or less November 11 and January 30. (I don’t know the sunrise dates.)

In Manhattan the sunrise dates are December 5 and January 8, and the sunset dates are May 28 and July 13.

User avatar
orin stepanek
Plutopian
Posts: 8200
Joined: Wed Jul 27, 2005 3:41 pm
Location: Nebraska

Re: APOD: A Picturesque Equinox Sunset (2022 Mar 20)

Post by orin stepanek » Sun Mar 20, 2022 6:05 pm

EquinoxSunset_Christen_960.jpg
A pretty picture' yes indeed'
but nasty to drive against!
Equinox; you're a pretty sight;
but you blind me, early morning;
and early night!
Orin

Smile today; tomorrow's another day!

User avatar
orin stepanek
Plutopian
Posts: 8200
Joined: Wed Jul 27, 2005 3:41 pm
Location: Nebraska

Re: APOD: A Picturesque Equinox Sunset (2022 Mar 20)

Post by orin stepanek » Sun Mar 20, 2022 6:07 pm

heehaw wrote: Sun Mar 20, 2022 9:52 am Sun in your eyes! Driving danger! If only road grids had been laid out NE to SW!
there would be a time of year that that would have a bad day also! :roll:
Orin

Smile today; tomorrow's another day!

Wolf
Ensign
Posts: 21
Joined: Thu Mar 24, 2016 8:43 pm

Re: APOD: A Picturesque Equinox Sunset (2022 Mar 20)

Post by Wolf » Sun Mar 20, 2022 9:56 pm

Ah yes, Roscoe Road, Rockton, IL. Have Six Vernal Equinox past so quickly?

Post Reply