Satellites are only visible shortly after sunset and before sunrise, known as astronomical twilight.
It’s just as easy to capture incredible images of the night sky, even during astronomical twilight, with image processing. Here’s photos I’ve captured in my driveway in the SF Bay Area: https://bradgessler.github.io/observatory-blog/observations/
I captured said images with an Elixir software stack I installed on a Pi and hooked up to my telescope. It’s open-source at https://github.com/bradgessler/observatory for those who are interested. I hook Claude up to it and it runs observations for the night, processes images with deterministic tools, and publishes them as the night progresses.
The hard part came next. Larsen spent about 45 hours layering the individual photos – each of which contained about 25 satellites – over one another, using Adobe Photoshop. Much of the time was spent painstakingly erasing stars, to reveal the satellites.
This is less an "image of our satellite-choked night skies" and more "a completely mendacious image produced using Photoshop".
You are being uncharitable. There is nothing misleading about this, or any other, nightsky timeseries image. It claims to show the paths of satellites over 2 hours, and that's what it does. You have to edit things like this to reveal the signal and keep relatively constant elements from overwhelming the result. Astronomers do this exact same thing (erasing things that obscure the subject over time).
Even if I were to be as charitable as possible to your interpretation, "mendacious" is way too strong a word, and implies an unreasonable bitterness.
I have no problem with the image and it illustrates a real phenomena. There is something slightly misleading about it though: if you point a camera in the same direction for 2 hours, take many images and then layer the images you wouldn't have a static star background like is shown here. You'd only get that star background if you used a star tracker and kept pointing at the same place in the night sky but then the foreground would be changing.
The purpose of stacking hundreds of photos is to get rid of noise and unwanted trails like this.
The effort involved here is to go out of your way to do the exact opposite, specifically make sure things that are in a single exposure show up in the stack.
The guy who actually made the image seems to just think it's cool: "I knew if I carried on it would look even better and more impressive in terms of satellite numbers."
But the framing from others is terrible. "Who gave anyone permission do this?" Um, every single satellite ever launched has gone through government approvals. Sorry if you didn't start paying attention to the world of space flight until it ruined your attempt at photography, but that's on you.
lol what. Regular citizens don’t get a say on satellites and many would prefer we didn’t put so many up. “National Security” will trump any citizen concerns every time.
If you do the exact opposite then? You take a very long exposure and you mask away the satellite trails and post the image as "image of how the satellites don't pollute the sky".. that's the exact same thing in reverse.
I don't understand. Are you laboring under the impression that the artist is trying to convince people that this is what the night sky looks like at any given moment? What even are you upset about?
Almost any astronomy processing software does this for free, because when you stack a whole load of images it rejects outlier pixels (e.g. a trail present on only one image out of hundreds).
It then usually gives you an image of both the combined success, and an image of just those pixels that were rejected. So, this.
Actually, this is pretty common for non-scientific astrophotography! Erase Stars -> Edit background and stars colour, contrast etc separately -> Recombine!
The misleading part is that readers don’t see that it’s provocative art until you carefully read the details. It’s presented like documentary evidence of what the problem looks like.
The photographer might not have intended it this way, but the writers of this post took advantage of that.
There's nothing misleading about removing light sources to reveal other light sources. You're speaking as though they erased all the sky's stars. The image is full of stars. This is petty.
The photographer was completely transparent about how the image was produced and what it means.. how you manage to color this as dishonest is beyond me.
A lot of people are going to look at that manually edited image, think it's a traditional long-exposure photo, and conclude that satellites are much more of a problem for astronomy than they really are.
The photographer made a really neat picture, but Kottke is presenting it with a headline that suggests its something else, and generally not giving enough context (mostly just blockquotes).
Ironically, the same technique used to remove the stars and isolate the satellites could have been used to remove the satellites and isolate the stars.
It would take 100X less effort to remove the satellites.
> Much of the time was spent painstakingly erasing stars, to reveal the satellites.
Many more stars than satellites in every frame. Erasing a couple satellites at most is quick. Erasing every star in the sky and keeping a couple satellites is not.
Its parameters are very well described and the result is beautiful (visually), interesting, and provocative. Yes, people will misinterpret all sorts of things like this, but I don't know what else the author could have done besides not create it at all, for fear of... these accusations?
Technically it is a limited resource, since there is only a finite volume. But we're nowhere near close to any notion of it being "full." Efficient rent would be approximately zero.
To whom would they pay 'rent'? What would be done with the money?
Don't go there, it leads to nothing but more waste, abuse and corruption. If it becomes necessary there can be some form of arbitrage in how LEO is used, we're not there yet though. Maybe something like the auctions for bandwidth for mobile operators but again, where does the money go? If institutionalised it will just turn into another slush fund for whatever interests, many of them corrupt or nonsensical, to drain.
It is a bit ridiculous these days and it's only going to get worse with basically every major country needing to do a version of this for defence purposes.
Go out tonight and just look at the sky for 5 mins and I'll guarantee you'll see a couple of satellites flying past.
As with a lot of other technologies, the genie is out of the bottle and I don't think we're putting him back there again, this is the future.
What makes it "ridiculous"? I can go outside and look at the sky for five minutes and see airplanes flying past, does that mean our air traffic is also ridiculous?
Of all the things to be outraged over... satellites provide extremely valuable services and are pretty near harmless. There's the pollution from the launches, some uncertain concern over putting materials into the upper atmosphere when they reenter, and that's about it. The thing people complain about most is that they get in the way of photographs of the starts. Which is annoying, but also seems to be easily worked around, and is pretty small potatoes compared to planet-wide communications. Your neighbor operating a leaf blower with a dirty two-stroke engine is harming you more than these satellites are.
Most satellites in low orbit are Starlink, and most Starlink satellites are at either 43° or 53° inclinations, so it's probably those. These inclinations cover most of the population in the most efficient manner. Low inclinations don't cover people at higher latitudes. (Inclination is equal to the highest latitude that the satellite will reach, and then coverage extends a little further since they have some slant range.) Higher inclinations waste more time over unpopulated regions.
I guess given we have the location, time and what looks like venus to the bottom right it should be possible to figure out the direction the picture was taken in to figure out the exact inclinations of the orbits but yeah, makes sense it'd be starlink
54 comments:
A few things:
Satellites are only visible shortly after sunset and before sunrise, known as astronomical twilight.
It’s just as easy to capture incredible images of the night sky, even during astronomical twilight, with image processing. Here’s photos I’ve captured in my driveway in the SF Bay Area: https://bradgessler.github.io/observatory-blog/observations/
I captured said images with an Elixir software stack I installed on a Pi and hooked up to my telescope. It’s open-source at https://github.com/bradgessler/observatory for those who are interested. I hook Claude up to it and it runs observations for the night, processes images with deterministic tools, and publishes them as the night progresses.
The hard part came next. Larsen spent about 45 hours layering the individual photos – each of which contained about 25 satellites – over one another, using Adobe Photoshop. Much of the time was spent painstakingly erasing stars, to reveal the satellites.
This is less an "image of our satellite-choked night skies" and more "a completely mendacious image produced using Photoshop".
These are actual images from a telescope with no photoshop: https://noirlab.edu/public/images/iau-ann19035a/ https://noirlab.edu/public/images/iotw1946a/
The image in the original post is not too far from what you get with an actual telescope.
You are being uncharitable. There is nothing misleading about this, or any other, nightsky timeseries image. It claims to show the paths of satellites over 2 hours, and that's what it does. You have to edit things like this to reveal the signal and keep relatively constant elements from overwhelming the result. Astronomers do this exact same thing (erasing things that obscure the subject over time).
Even if I were to be as charitable as possible to your interpretation, "mendacious" is way too strong a word, and implies an unreasonable bitterness.
I have no problem with the image and it illustrates a real phenomena. There is something slightly misleading about it though: if you point a camera in the same direction for 2 hours, take many images and then layer the images you wouldn't have a static star background like is shown here. You'd only get that star background if you used a star tracker and kept pointing at the same place in the night sky but then the foreground would be changing.
No it is correct. I dabble in astrophotography.
The purpose of stacking hundreds of photos is to get rid of noise and unwanted trails like this.
The effort involved here is to go out of your way to do the exact opposite, specifically make sure things that are in a single exposure show up in the stack.
The image itself is interesting, but the context in which it’s presented in this article is dishonest.
The headline is the worst offender, saying that the skies are “choked” with satellites.
The headline is misleading. The photo alone is interesting with the right context.
The guy who actually made the image seems to just think it's cool: "I knew if I carried on it would look even better and more impressive in terms of satellite numbers."
But the framing from others is terrible. "Who gave anyone permission do this?" Um, every single satellite ever launched has gone through government approvals. Sorry if you didn't start paying attention to the world of space flight until it ruined your attempt at photography, but that's on you.
lol what. Regular citizens don’t get a say on satellites and many would prefer we didn’t put so many up. “National Security” will trump any citizen concerns every time.
To be fair, the majority of satellites now seems to exist because "money" will trump any citizen concerns every time.
Agreed, I should’ve added that as the other overriding case
Not sure how you saw "government" and read it as "regular citizens," but do go back and read it again.
Exactly. The regular citizens don’t get to participate in the decision.
If you do the exact opposite then? You take a very long exposure and you mask away the satellite trails and post the image as "image of how the satellites don't pollute the sky".. that's the exact same thing in reverse.
Both can't be non-misleading right?
I don't understand. Are you laboring under the impression that the artist is trying to convince people that this is what the night sky looks like at any given moment? What even are you upset about?
It did say he was a photographer, not an astronomer.
Surely an astronomer would have software for this that would produce a more accurate picture.
Almost any astronomy processing software does this for free, because when you stack a whole load of images it rejects outlier pixels (e.g. a trail present on only one image out of hundreds).
It then usually gives you an image of both the combined success, and an image of just those pixels that were rejected. So, this.
An astronomer would presumably not erase the stars.
Why not? Stars are boring, the cool things are galaxies.
Actually, this is pretty common for non-scientific astrophotography! Erase Stars -> Edit background and stars colour, contrast etc separately -> Recombine!
The point of the image is to make a point. Art is provocative. Our skies are choked as anyone who makes Astro images will tell you.
> Art is provocative
The misleading part is that readers don’t see that it’s provocative art until you carefully read the details. It’s presented like documentary evidence of what the problem looks like.
The photographer might not have intended it this way, but the writers of this post took advantage of that.
The first sentence literally says it’s a multi image composite so…
That’s not the misleading part. You don’t need an explanation to see that it’s a composite.
The misleading part is where he edited out the stars by hand.
> Much of the time was spent painstakingly erasing stars, to reveal the satellites.
The photographer wasn’t misleading. He made a cool photo. The headline is misleading.
There's nothing misleading about removing light sources to reveal other light sources. You're speaking as though they erased all the sky's stars. The image is full of stars. This is petty.
I really like the photo and what it represents. We're growing as a civilization and I think that's beautiful.
Meanwhile I’d like to be able to enjoy the stars without Elon’s shit in my face. Can’t wait for the Coca Cola advertisements some day.
The rest of us enjoy having high speed internet globally.
"Rest of us" is not a reasonable phrase here. You do not speak for the global population. It's not everybody vs bix6.
The photographer was completely transparent about how the image was produced and what it means.. how you manage to color this as dishonest is beyond me.
It’s called art.
Has he not heard of AI?
A lot of people are going to look at that manually edited image, think it's a traditional long-exposure photo, and conclude that satellites are much more of a problem for astronomy than they really are.
The photographer made a really neat picture, but Kottke is presenting it with a headline that suggests its something else, and generally not giving enough context (mostly just blockquotes).
Ironically, the same technique used to remove the stars and isolate the satellites could have been used to remove the satellites and isolate the stars.
It would take 100X less effort to remove the satellites.
Why is that ironic?
You're just pointing out that there are tools to automate this.
Why any less effort? Masking the stars out and masking them in should take the same amount of time and effort.
From the article:
> Much of the time was spent painstakingly erasing stars, to reveal the satellites.
Many more stars than satellites in every frame. Erasing a couple satellites at most is quick. Erasing every star in the sky and keeping a couple satellites is not.
Its parameters are very well described and the result is beautiful (visually), interesting, and provocative. Yes, people will misinterpret all sorts of things like this, but I don't know what else the author could have done besides not create it at all, for fear of... these accusations?
Photographer made a cool photo.
Headline writer, a different person, used it to create misleading headlines.
"Photographer made a cool image"
There I fixed it for you. This isn't a photo in any traditional sense.
I remember when this was more of a theoretical problem :( https://news.ycombinator.com/item?id=24128726 compare when i made that comment in 2020 https://satellitemap.space/s/8Tu9xcHa
with now https://satellitemap.space/s/R4YUwDQn
I want to thank those little guys up there for google maps, internet, tv, weather, rescues, whatever else they do. Put up some more.
It looks like low earth orbit is a limited resource. Is it?
If so, do Starlink and others pay rent? Should they (to ensure efficient use of the resource)?
LEO will be worthless soon enough.
https://outerspaceinstitute.ca/crashclock/
Technically it is a limited resource, since there is only a finite volume. But we're nowhere near close to any notion of it being "full." Efficient rent would be approximately zero.
To whom would they pay 'rent'? What would be done with the money?
Don't go there, it leads to nothing but more waste, abuse and corruption. If it becomes necessary there can be some form of arbitrage in how LEO is used, we're not there yet though. Maybe something like the auctions for bandwidth for mobile operators but again, where does the money go? If institutionalised it will just turn into another slush fund for whatever interests, many of them corrupt or nonsensical, to drain.
It is a bit ridiculous these days and it's only going to get worse with basically every major country needing to do a version of this for defence purposes.
Go out tonight and just look at the sky for 5 mins and I'll guarantee you'll see a couple of satellites flying past.
As with a lot of other technologies, the genie is out of the bottle and I don't think we're putting him back there again, this is the future.
What makes it "ridiculous"? I can go outside and look at the sky for five minutes and see airplanes flying past, does that mean our air traffic is also ridiculous?
Of all the things to be outraged over... satellites provide extremely valuable services and are pretty near harmless. There's the pollution from the launches, some uncertain concern over putting materials into the upper atmosphere when they reenter, and that's about it. The thing people complain about most is that they get in the way of photographs of the starts. Which is annoying, but also seems to be easily worked around, and is pretty small potatoes compared to planet-wide communications. Your neighbor operating a leaf blower with a dirty two-stroke engine is harming you more than these satellites are.
ouch more dishes than a tapas bar
it seems fairly evenly distributed besides the aggregation in the middle, what orbit would that be? why are there so many satellites there?
Most satellites in low orbit are Starlink, and most Starlink satellites are at either 43° or 53° inclinations, so it's probably those. These inclinations cover most of the population in the most efficient manner. Low inclinations don't cover people at higher latitudes. (Inclination is equal to the highest latitude that the satellite will reach, and then coverage extends a little further since they have some slant range.) Higher inclinations waste more time over unpopulated regions.
I guess given we have the location, time and what looks like venus to the bottom right it should be possible to figure out the direction the picture was taken in to figure out the exact inclinations of the orbits but yeah, makes sense it'd be starlink
Looks like some of the first 8-bit Moiré pattern demos.
Makes perfect sense.
https://en.wikipedia.org/wiki/Moir%C3%A9_pattern
* https://www.instagram.com/p/Dei4FQ0HSt-
* https://satellitemap.space
* https://platform.leolabs.space/visualization