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APOD: Perseid Meteors over Stonehenge (2024 Aug 12)
Posted: Mon Aug 12, 2024 4:07 am
by APOD Robot
Perseid Meteors over Stonehenge
Explanation: What's happening in the sky above Stonehenge? A meteor shower: specifically, the
Perseid meteor shower. A few nights ago, after the
sky darkened, many images of meteors from this year's
Perseids were captured separately and merged into a single frame. Although the
meteors all traveled on straight paths, these paths appear slightly curved by the wide-angle lens of the capturing camera. The
meteor streaks can all be traced back to a single point on the sky called the
radiant, here just off the top of the frame in the
constellation of Perseus. The same camera took a deep image of the background sky that brought up the
central band of our
Milky Way galaxy running nearly vertical through the image center. The
featured image was taken from
Wiltshire,
England, being careful to include, at the bottom, the famous astronomical monument of
Stonehenge. Although the
Perseids peaked last night, some Perseid meteors should
still be visible for a few more nights.
Re: APOD: Perseid Meteors over Stonehenge (2024 Aug 12)
Posted: Mon Aug 12, 2024 4:33 am
by Ann
A beautiful Milky Way Perseid shower over Stonehenge with a blue UFO! Really people, don't you see it?
What is that blue thingy? Oh, it's Vega, of course. If you see one blue object hovering over the northern Milky Way, you can bet your boots it's Vega. So why does Vega come equipped by a pair of airplane wings? Beats me, although I think that there are smart people here who can explain.
Very nice image, but I'll leave it to the rest of you to add more comments!
Ann
Re: APOD: Perseid Meteors over Stonehenge (2024 Aug 12)
Posted: Mon Aug 12, 2024 11:50 am
by Roy
As previous posts would have it, those meteors are coming in at 60 miles per second. Care to speculate why some streaks show TWO bright finish burnout flares?
Re: APOD: Perseid Meteors over Stonehenge (2024 Aug 12)
Posted: Mon Aug 12, 2024 12:48 pm
by johnnydeep
Roy wrote: ↑Mon Aug 12, 2024 11:50 am
As previous posts would have it, those meteors are coming in at 60 miles per second. Care to speculate why some streaks show TWO bright finish burnout flares?
I think it's merely because meteors are not uniformly composed and disintegrate - and explode - in phases according to their particular composition.
Re: APOD: Perseid Meteors over Stonehenge (2024 Aug 12)
Posted: Mon Aug 12, 2024 1:11 pm
by Chris Peterson
Roy wrote: ↑Mon Aug 12, 2024 11:50 am
As previous posts would have it, those meteors are coming in at 60 miles per second. Care to speculate why some streaks show TWO bright finish burnout flares?
60 km/s. Meteors can't be as fast as 60 miles per second.
Meteoroids are very non-uniform, especially when they are cometary dust, which is often described as "fluffy". One thing they commonly do when they experience the massive forces on them as they encounter air resistance is to partially fragment, which instantly exposes more surface area to ablation and creates a sudden increase in brightness. It is common for larger particles (greater than a few millimeters) to experience one or more such disruptions. When they occur at the end of the trail, they are called terminal explosions.
Re: APOD: Perseid Meteors over Stonehenge (2024 Aug 12)
Posted: Mon Aug 12, 2024 3:26 pm
by AVAO
Ann wrote: ↑Mon Aug 12, 2024 4:33 am
A beautiful Milky Way Perseid shower over Stonehenge with a blue UFO! Really people, don't you see it?
APOD 12 August 2024 detail annotated .png
What is that blue thingy? Oh, it's Vega, of course. If you see one blue object hovering over the northern Milky Way, you can bet your boots it's Vega. So why does Vega come equipped by a pair of airplane wings? Beats me, although I think that there are smart people here who can explain.
Very nice image, but I'll leave it to the rest of you to add more comments!
Ann
https://www.salisburyjournal.co.uk/news ... tonehenge/
..I like the picture from Nick Bull a little bit more, because the individual meteors still appear as straight lines and the stars remain as point sources and not as UFOs...
...but that's an aesthetic question and a question of the technical equipment used. Both pictures are great.
Re: APOD: Perseid Meteors over Stonehenge (2024 Aug 12)
Posted: Tue Aug 13, 2024 4:01 am
by D.C.Ceva
Ann wrote: ↑Mon Aug 12, 2024 4:33 am
A beautiful Milky Way Perseid shower over Stonehenge with a blue UFO! Really people, don't you see it?
APOD 12 August 2024 detail annotated .png
What is that blue thingy? Oh, it's Vega, of course. If you see one blue object hovering over the northern Milky Way, you can bet your boots it's Vega. So why does Vega come equipped by a pair of airplane wings? Beats me, although I think that there are smart people here who can explain.
Very nice image, but I'll leave it to the rest of you to add more comments!
Ann
Hello.
I was caught by it, too, first thinking perhaps a comet with its tails more opposed than usual and head-on. But Vega it is
Perhaps a long-exposure light effect?
Or perhaps someone's asking for Ellie...
Re: APOD: Perseid Meteors over Stonehenge (2024 Aug 12)
Posted: Tue Aug 13, 2024 5:43 pm
by RJN
FYI I have been informed that this image and APOD were covered in an online BBC article
here:
https://www.bbc.com/news/articles/cz07l3glkdmo
Re: APOD: Perseid Meteors over Stonehenge (2024 Aug 12)
Posted: Sat Aug 17, 2024 5:13 pm
by gwrede
Like most of us, I was perplexed by the
blue wings of the star halfway up the picture, to the right of the Milky Way.
After some deliberation, my theory is that this photo was taken with a very wide angle lens. Such lenses tend to have quite a large lens at the front. Their absolute aperture is very small, because the F-stop value is proportional to the focal length. All this means, that a smudge on the lens impacts only a little part of the picture in wide angle lenses, while a smudge on a telephoto lens affects the entire picture.
So, it looks like there was a finger smudge at that particular spot. That smudge has to be done with a moving finger, because then it creates parallel grease ridges, which gives that kind of wings to bright objects. This is often seen in phone pictures with dirty lenses. (And because the phone camera is so little, the finger smudges tend to cover a good part of the entire lens.)
If Mr. Dury has used the very equipment he has in the photo in the BBC article (
https://www.bbc.com/news/articles/cz07l3glkdmo ), then this would be a plausible explanation.
Re: APOD: Perseid Meteors over Stonehenge (2024 Aug 12)
Posted: Sat Aug 17, 2024 5:32 pm
by Chris Peterson
gwrede wrote: ↑Sat Aug 17, 2024 5:13 pm
Like most of us, I was perplexed by the
blue wings of the star halfway up the picture, to the right of the Milky Way.
After some deliberation, my theory is that this photo was taken with a very wide angle lens. Such lenses tend to have quite a large lens at the front. Their absolute aperture is very small, because the F-stop value is proportional to the focal length. All this means, that a smudge on the lens impacts only a little part of the picture in wide angle lenses, while a smudge on a telephoto lens affects the entire picture.
So, it looks like there was a finger smudge at that particular spot. That smudge has to be done with a moving finger, because then it creates parallel grease ridges, which gives that kind of wings to bright objects. This is often seen in phone pictures with dirty lenses. (And because the phone camera is so little, the finger smudges tend to cover a good part of the entire lens.)
If Mr. Dury has used the very equipment he has in the photo in the BBC article (
https://www.bbc.com/news/articles/cz07l3glkdmo ), then this would be a plausible explanation.
A smudge anywhere on the surface of the objective will impact all parts of the image equally, regardless of the focal length of that objective.
Re: APOD: Perseid Meteors over Stonehenge (2024 Aug 12)
Posted: Sun Aug 18, 2024 6:51 pm
by RJN
... and here the image / APOD is discussed on Reddit and space.com:
https://www.reddit.com/r/space/s/64i05OMdCT .
