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Posted: **Tue Jun 18, 2024 4:07 am**

Gigantic Jets over Himalayan Mountains

Explanation: Yes, but can your thunderstorm do this? Pictured here are gigantic jets shooting up from a thunderstorm last week toward the Himalayan Mountains in China and Bhutan. The composite image captured four long jets that occurred only minutes apart. Gigantic jets, documented only in this century, are a type of lightning discharge that occurs between some thunderstorms and the Earth's ionosphere high above them. They are an unusual type of lightning that is much different from regular cloud-to-cloud and cloud-to-ground lightning. The bottoms of gigantic jets appear similar to a cloud-to-above strike called blue jets, while the tops appear similar to upper-atmosphere red sprites. Although the mechanism and trigger that cause gigantic jets remains a topic of research, it is clear that the jets reduce charge imbalance between different parts of Earth's atmosphere. A good way to look for gigantic jets is to watch a powerful but distant thunderstorm from a clear location.

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Posted: **Tue Jun 18, 2024 5:55 am**

more details:
Jets and Sprites over Kuragangri Snow Mountain on 10 June 2024
From: Lurila Observatory, China, Stack of five photos

Is this 5 or 4 exposures?
What is the water body at foreground (is it Yamdrok Lake, so Lhasa is 100 km (62 mi) to the northeast)?

Posted: **Tue Jun 18, 2024 8:34 am**

VictorBorun wrote: ↑Tue Jun 18, 2024 5:55 am more details:
Jets and Sprites over Kuragangri Snow Mountain on 10 June 2024
From: Lurila Observatory, China, Stack of five photos

Is this 5 or 4 exposures?
What is the water body at foreground (is it Yamdrok Lake, so Lhasa is 100 km (62 mi) to the northeast)?

And in the explanation, it's mentioned that there are 4 jets captured in this picture. But I see 5?

Posted: **Tue Jun 18, 2024 2:18 pm**

the stars are fixed in this APOD. I guess they are from one short exposure, not a series of exposures 10 minutes apart.
But I wonder if it's possible to see a sprite and the star field in one exposure.
If a sprite lasts for 3-100 ms (and in a shorter exposure resolves to a ball, moving up at the speed of 30,000 km/s and covering 70 km in 2 ms), then you need a 3-100 ms exposure to make sprite look as bright as possible against the sky.
But then the stars would look pretty dim?

Posted: **Tue Jun 18, 2024 2:44 pm**

The image is striking (pun intended). The number of Jets is a good question. It appears that there are 5 with 2 converging and one (on the right) diverging. But, I am wondering what is the bright object in the middle of the frame?

Posted: **Tue Jun 18, 2024 7:17 pm**

Fast Eddie wrote: ↑Tue Jun 18, 2024 2:44 pm The image is striking (pun intended). The number of Jets is a good question. It appears that there are 5 with 2 converging and one (on the right) diverging. But, I am wondering what is the bright object in the middle of the frame?

to answer that we need to recognize the star field. Is there a star field recognition software?

Posted: **Tue Jun 18, 2024 11:22 pm**

VictorBorun wrote: ↑Tue Jun 18, 2024 7:17 pm
Fast Eddie wrote: ↑Tue Jun 18, 2024 2:44 pm The image is striking (pun intended). The number of Jets is a good question. It appears that there are 5 with 2 converging and one (on the right) diverging. But, I am wondering what is the bright object in the middle of the frame?
to answer that we need to recognize the star field. Is there a star field recognition software?

Ah well, given the scale of the frame, near the horizon, northern hemisphere summer, there's only one globular cluster it could possibly be, that is the greatest cluster of them all, Omega Centauri. This is confirmed by the three bright blue stars that form a triangle above and to the left, they are the characteristic finder stars for Omega Centauri, I had to look these up, they are Mu, Nu, and Phi Centauri.

And now that I'm zooming into the pixels and comparing with Stellarium around the region, I think the photographer has at least doubled the star field, just about an hour apart, probably they stacked all exposures for the jets. Look closely and you'll see that central triangle of blue stars above Omega Centauri has an identical double of itself, just where we would expect it to be an hour later. So that means what appears to be a second dimmer globular cluster to the bottom right is actually just Omega Centauri again on another exposure an hour later, dimmed by haze near the horizon.

Edit: wait, maybe this is a partial answer to your question about exposure time, the photographer included the second omega centauri because it is partially behind one of the jets, so the amount that it's dimmer must be representative of how much brighter the jets are than the globular cluster. So these jets are actually not that bright, at least from this distance, since they can't completely outshine a globular cluster that usually requires binoculars.

Very beautiful picture and great effort by the photographer, thanks to them and APOD for sharing!

Posted: **Wed Jun 19, 2024 4:09 am**

florid_snow wrote: ↑Tue Jun 18, 2024 11:22 pm
VictorBorun wrote: ↑Tue Jun 18, 2024 7:17 pm
Fast Eddie wrote: ↑Tue Jun 18, 2024 2:44 pm The image is striking (pun intended). The number of Jets is a good question. It appears that there are 5 with 2 converging and one (on the right) diverging. But, I am wondering what is the bright object in the middle of the frame?
to answer that we need to recognize the star field. Is there a star field recognition software?
Ah well, given the scale of the frame, near the horizon, northern hemisphere summer, there's only one globular cluster it could possibly be, that is the greatest cluster of them all, Omega Centauri. This is confirmed by the three bright blue stars that form a triangle above and to the left, they are the characteristic finder stars for Omega Centauri, I had to look these up, they are Mu, Nu, and Phi Centauri.

And now that I'm zooming into the pixels and comparing with Stellarium around the region, I think the photographer has at least doubled the star field, just about an hour apart, probably they stacked all exposures for the jets. Look closely and you'll see that central triangle of blue stars above Omega Centauri has an identical double of itself, just where we would expect it to be an hour later. So that means what appears to be a second dimmer globular cluster to the bottom right is actually just Omega Centauri again on another exposure an hour later, dimmed by haze near the horizon.

Edit: wait, maybe this is a partial answer to your question about exposure time, the photographer included the second omega centauri because it is partially behind one of the jets, so the amount that it's dimmer must be representative of how much brighter the jets are than the globular cluster. So these jets are actually not that bright, at least from this distance, since they can't completely outshine a globular cluster that usually requires binoculars.

Very beautiful picture and great effort by the photographer, thanks to them and APOD for sharing!

Thanks a bunch, Florid Snow!

I thought it couldn't be Omega Centauri because it would be too far south from Bhutan... but I was wrong there, as you can see if you read this.

Ann

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APOD: Gigantic Jets over Himalayan Mountains (2024 Jun 18)

APOD: Gigantic Jets over Himalayan Mountains (2024 Jun 18)

Re: APOD: Gigantic Jets over Himalayan Mountains (2024 Jun 18)

Re: APOD: Gigantic Jets over Himalayan Mountains (2024 Jun 18)

Re: APOD: Gigantic Jets over Himalayan Mountains (2024 Jun 18)

Re: APOD: Gigantic Jets over Himalayan Mountains (2024 Jun 18)

Re: APOD: Gigantic Jets over Himalayan Mountains (2024 Jun 18)

Re: APOD: Gigantic Jets over Himalayan Mountains (2024 Jun 18)

Re: APOD: Gigantic Jets over Himalayan Mountains (2024 Jun 18)