Advancing Terminator or ?


Active Member
Last night I flew from Denver to Burbank and observed the following:
My phone is a relatively poor iPhone 8 SE which contains the iPhone 6 camera, so my apologies for the quality.

Details in a minute, but I think I’m seeing the earth’s shadow in the dark zone near the ground, with sunlit atmosphere above. Am I right? Or is something else going on here?

This was at 8:58 pm, mountain time, June 23, 2022. I was on NW2369 (Southwest). As I recall we were roughly south of Las Vegas at the time, but my phone was still on mountain time.

Thanks in advance for your thoughts.


Senior Member.
This was at 8:58 pm, mountain time, June 23, 2022.
That's June 24, 2:58 UTC.
The latitude of Las Vegas, NV, USA is 36.114647, and the longitude is -115.172813.
With a radar track of your flight, your position and altitude could be pinned down more exactly.
12 km ≈ 39000 ft.

I don't know if the site does atmospheric refraction to extend the horizon properly, and I advanced the clock 15 minutes. Play around with the settings yourself.
Screenshot_20220625-091401_Samsung Internet.jpg


Active Member
Thanks, @Mendel, that’s a great site. I wondered why you advanced the time by 15 minutes until I tied different times myself. It looks like the lights were not visible when I took the photo, but 15 minutes later, Las Vegas was well lit in comparison.

Z.W. Wolf

Senior Member.
And above the shadow is a faint Belt of Venus.

belt-of-venus-diagram png.png
As the Sun rises in the east or sets in the west, sunlight reflects off the dense atmosphere in an effect called backscattering, which creates a pink band of light on the opposite horizon to the Sun, above the antisolar point. This pink band is the Belt of Venus.

When the Sun is below the observer’s line of sight, incoming sunlight passes through more atmosphere near the horizon, which causes the observer to see pink wavelengths of light backscattered from the atmosphere.

The resulting pink band, the Belt of Venus, appears above Earth’s shadow.


Backscatter (or backscattering) is the reflection of waves, particles, or signals back to the direction from which they came.

In my experience the desert is the place to be to see a vivid Belt of Venus


We're also seeing some anti-crepuscular rays.
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Z.W. Wolf

Senior Member.
No, not mine. I have Kodachrome slides that look much like this. Someday I'll get around to scanning.