green flashes after sunset

[ozfactor]

Please excuse the colloquial vernacular, I am not an astronomer but a night sky enthusiast and have for many years pondered this question. Has anyone else observed, much after sunset on clear night skies dim greenish yellow brief flashes that occur at random intervals sometimes as frequently up to every 15-20 min on clear night skies? I have pulled weather radar, no storm systems for hundreds of miles. I have seen these both in remote high desert areas of North America and also areas with decent amounts of light pollution. I know it’s not my eyes playing tricks on me because these have been seen with several other individuals who have confirmed my observations. Could this be space junk or meteorites? When I say they illuminate the entire night sky I do mean everything from horizon all the way up. A bit dim and quite brief maybe 50 milliseconds or so. Wish I could film the phenomenon but I don’t have the equipment. Thanks for your comments.

[Knighty2112]

 

https://www.space.com/green-flash-earth-sunrise-sunset

[ollypenrice]

As Gus says, the Green Flash Effect comes to mind. This link discusses four forms that it can take.

https://www.aaas.org/catching-elusive-green-flash#:~:text=The green flash is a,earth's atmosphere like a prism.

Olly

[Bugdozer]

4 hours ago, Knighty2112 said:

 

https://www.space.com/green-flash-earth-sunrise-sunset

This obviously isn't what the OP is describing though, is it? 

[dweller25]

@ozfactor

There are quite a few reports of this.

It’s possible that you are seeing the green/yellow flash of a distant small meteorite burning up.

Edited February 4 by dweller25

[ollypenrice]

52 minutes ago, Bugdozer said:

This obviously isn't what the OP is describing though, is it? 

I was wondering if, in flat desert areas, there might be successive green flash effects from sunsets at a greater distance from the observer. I've no idea if this is possible but mirages are also necessary.

David's explanation above seems more plausible, though.

Olly

[ozfactor]

Most logical explanation to me was the “exploding meteorite” theory except the flash duration and color are seemingly consistent. However from my research into this topic, I understand it is quite rare to observe exploding meteorites. I have observed the flashes hours into the night, much after sunset, so I ruled out sunset “green flash”. So consistent are the flash color and duration that they seem manmade to me. Which got me wondering, (background is aerospace and mechanical engineering) if this could be related to some sort of classified military tech. Theorize that if there is a sufficiently bright light source high enough above the atmosphere to scatter, it could be a form of radar used to periodically scan for incoming enemy missiles, stealth aircraft… potential detection by looking upwards for an object’s shadow. Sounds crazy I know…

Other than that I cannot rule out atmospheric electrical discharges absent of any cloud cover. Not sure if such a meteorological phenomenon exists or not. But they do look a LOT like when distant flashes of lightning illuminate the sky.

Edited February 6 by ozfactor

[Leo S]

I think you are right to discard meteors as a potential cause.

While it's not uncommon for meteors of fireball magnitude/brightness to produce very bright green flashes that can briefly illuminate the entire sky, a frequency of minutes suggests something else. I ran multiple cameras night after night for a couple of years and they caught a few (example #1, #2), but only on major shower peak nights is it usual to catch more than one or two in a night.

It is also possible for there to be multiple fireballs over the course of minutes (it happened in November 1998, which is what got me interested in the subject in the first place) but can also happen during the peaks of stronger annual showers like the Geminids, but I think if that were the case, you'd probably also see the fireballs themselves, assuming you had reasonable views of the skies.

I think the chances are that others would have observed, and reported the fireballs too is that were the cause, since fireballs can be observed from many hundreds of miles away - a display like your description suggests would likely not go unnoticed.

Given the above, my guess is that the flashes are much more localized and probably human related (military/pyrotechnics perhaps as you suggested), but perhaps there is still a chance it might be some unusual natural phenomenon.

"Earth Lights" perhaps? Have you checked seismological data for the area?

Lightning related phenomena can also be observed from hundreds of miles away potentially, and since we are at solar max perhaps that's worth checking too even though auroras may be unlikely at your latitude.

I'm guessing you have some very dark skies there where you are, and if that is the case you might be observing subtle flashes that might be missed elsewhere, although I'd have a hard time believing it's something unusual that everyone else is missing... but you never know. At the end of the day, there could be multiple possibilities that we are not thinking of - reminds me of this story from last year.

Please consider setting up a camera or two. They are game changers. They don't have to be expensive, as this thread shows, and they can often help in solving puzzles like this one.