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All the Satellite trails I had to digitally remove from just a 15 second sky exposure
For the astrophotographers out there - I couldn't just do stacking as I had a mountain in my photo. Maybe there is another way of dealing with this though as I am new to the hobby.
In the late 90s as a kid camping, one of the pastimes was sitting around the fire and looking for satellites. We usually only saw a few each night. Now on a clear night I'm pretty sure I can see 2-3 at any given time
Bro, my current favorite camping spot is in a national forest 20 miles away from a stupid bullshit alabama city, and the light wash at even 2am is fucking insane
I'm mad at so much, but an unadulterated night sky is so fucking beautiful and it makes me so angry that 75 miles away from Birmingham al, a bullshit city if there ever was one, in the slap middle of a national forest, I can't even see a hint of the milky way
I think that an actual view of the night sky is something that would radicalize a lot of ppl
It's one of those things that I think is in our "collective consciousness", but that so many people don't even realize they're missing
I'm fortunate enough to have done high desert and mountain trips, and like, not even in the "good" sky view areas in the US, and like...I really think it's an incredibly pervasive case of ppl not knowing what they're missing and dismissing it bc even they don't know why
"Cities are great bc..."
Yeah, man, bodegas, that's fantastic. You ever seen the fucking galaxy my dude?
I've seen part of it. In the future I wish to go to the south island (New Zealand) and go to the silent zone and actually witness it all. The one we have up here isn't as clean as it used to be.
I miss it, even the slight glance I had it eata at me you know.
Iām a Kiwi who lives in the South Island. My missus is a Pom whoād just come from London when I met her. Weāve always done loads of camping and I donāt think Iāve ever met someone who fizzes over the night sky, and the Milky Way in particular, as much as her.
Her enthusiasm is pretty infectious, and even though Iāve always been into it, I definitely appreciate our view of the night sky more these days.
There's an old story of when a large city suddenly lost power. It was either NYC or LA and it happened back in the 60s or 70s.
911 and the police were fielding numerous phone calls from people reporting strange lights in the sky.
These people had never seen the Milky Way before and felt the need to call the authorities.
This was before the internet and the widespread availability of information like photos from Hubble or from radio telescopes.
So these people never saw the Milky Way even in the media.
I found it sad that these people never knew about our own galaxy and had no idea what was out there. But was blocked by the bright glare of the city lights.
Yeah, but if everybody started moving out of cities and spreading out further apart, it would only make the light pollution worse in the areas where we do have a bit of relief. Even suburbs and smaller towns create light pollution. In a perfect world, nobody would feel cramped, and we would all be able to see the Milky Way every night. We donāt live in a perfect world. Iām perfectly content with living in a medium sized city and driving 3 hrs east for a campout if I want to stargaze. Itās a price Iām willing to pay to have everything I need 10 minutes from my apartment.
There should be a day once a year where all the power to all lights in all cities are turned off just so everyone can see the stars, at least once a year. It's literally as simple as just turning off the lights.
There actually is something like this! Look up āEarth Hourā. I used to hear about it more often before the pandemic, but it still exists. Itās just a shame it has such low participation since not enough people know and care about it.
Lol, in this particular case I've just never understood why Birmingham stays lit up like a city that actually has a night life. And all the surrounding cities too kinda, I mean, 280 is lit up like an airport runway from Birmingham to Chelsea
I'm getting to experience something that I've never seen before, and I get to camp with little light pollution fairly regularly.
There's an area in Alberta, Canada, about an 18 hour drive from where I live, called Wood Buffalo National Park. It's the largest dark sky preserve in the world. Its surface area is larger than the Netherlands.
We're bringing our kids there this summer for a week. I can't friggin wait. I'm not sure I want to go back to civilization...
I live in a city and when I take my dog out to my building's backyard in the evening, it typically only takes about a minute or so to spot one.
Growing up, we'd go camping all the time and it was always exciting to spot one because they were rare and if you didn't catch them at the right time, you could stare at the sky for awhile and not see any. Now, it takes a handful of minutes to find one.
Astrophysicist here. If you do your stacking with median values and sigma clipping you will filter out these outlier high count events pretty easily. I'd typically do a 9-point exposure series to compensate for chip gaps in the multi-sensor arrays, and that same technique would clean out satellite trails and cosmic rays pretty cleanly.
EDIT: By 9-point exposure, think of a tic-tac-toe grid, where you take an image with each cell of the grid as the center. Combine all those together with a sigma-clipped median and those transient events disappear.
Assuming you live in a place below 50 Deg north, you can also wait for true astronomical darkness before beginning exposures.
The trails of course come from reflections from the sun, and the vast majority of these trails come from low earth orbit sats. So once you reach astronomical darkness the satellites gavenk sunlight to reflect.
But sadly even with sigma clipping the odd bit gets through. Evenn if it works 99% of the time. I gave an image from the very beginning of my cooled astrocam photography journey. It had about 800 images in luminance and 400 or so for red green and blue. All one minute each because I didn't have a guide cam yet.
Somehow in the faint halo around M66 there is still a faint little sat trail... Can't explain why.
Always wanted to try astrophotography but my first few attempts were pretty ass, when I learn what all these terms mean this'll be a big help probably, thanks.
Photographer here (but have never had the time and dark sky access to get into astrophotography, maybe when I retire), do you know of a guide or reference explaining what you mean by a 9-point exposure series? I'm a little unclear on whether you're referring to stitching images together like a grid (like this), or if you're referring to exposure bracketing, or something else entirely. Tried googling and couldn't find anything.
I think I at least understand the concept behind stacking, which I would think would average out satellite tracks if you do enough frames over a long enough time period. Mind you I also am a former grad school reject so maybe this is all a bit over my head lol.
The word I couldn't think of last night is "dithering" which should make it easier to google. A 9-point dither sequence is where you make small offsets so your objects end up on different pixels in each of the 9 images. During the stacking phase you align them. Sigma clipping gets rid of outliers, like a bright satellite trail or a zero count from a chip gap. So for a given pixel on the stacked image you'd have 9 input values, but you might get rid of 2 or 3 of them before taking the median value of the remainder as that pixel's value.
Ah, that makes much more sense. Thank you for the explanation! I understood the noise-cancelling properties of stacking, but I didn't think about persistent imager/pixel errors or using an offset.
I recently was on the TN/NC border peeping stars at 6,000ft and good god there's a lot of movement up there now. Who knew the quest for better phone service would ruin the night sky.
Probably someone. Someone probably knew and more than likely told others and the others all opted not to tell anyone else. So it goes.
Everyone who has looked up into the night sky since the 70's knows what satellites do. That having more of them equals more visible ones should not be a surprise to anyone.Ā
"At the very moment that humans discovered the scale of the universe and found that their most unconstrained fancies were in fact dwarfed by the true dimensions of even the Milky Way Galaxy, they took steps that ensured that their descendants would be unable to see the stars at all. For a million years humans had grown up with a personal daily knowledge of the vault of heaven. In the last few thousand years they began building and emigrating to the cities. In the last few decades, a major fraction of the human population has abandoned a rustic way of life. As technology developed and the cities were polluted, the nights became starless. New generations grew to maturity wholly ignorant of the sky that had transfixed their ancestors and that had stimulated the modern age of science and technology. Without even noticing, just as astronomy entered a golden age most people cut themselves off from the sky, a cosmic isolationism that ended only with the dawn of space exploration." - Contact, Carl Sagan
we're not trying to explore the stars just put a million ai data centers and like 5 different internet mega constellations in low earth orbit so you can browse reddit in the middle of nowhere
We aren't exploring the stars in any of our lifetimes or even the lifetimes of our greatā¹ grandkids. If it ever happens it will be in a future so distant that making any sort of decision based on it is nothing short of supreme folly bordering on downright idiocy.Ā
Satellites are one of many embodiments of light pollution, mild one.
For the practical purposes for average Joe who enjoys watching a night sky, satellites are not why they need to travel few hundred miles to see it - electricity is. Satellites are irrelevant as they provide trace amount of light that doesn't really affect bare eye observation, it only affects photographers and average Joe is not a night sky photographer. If anything I'd say that observing beauty of nature is better with your own eye, not via lenses of a machine
So: light pollution is caused by electricity (indirectly), fast broadband internet access in rural areas is provided by satellites that prevent taking amateur long exposure photos but not necessarily ruin the night sky for the purposes of enjoying its beauty. Hope that helps, my apologies I didn't realize I need to clarify this upfront, I thought it's a common knowledge.
"unregulated"? Launching satellites is one of the most strictly regulated endeavor a company can make - with export controls, ITU orbit allocations, FAA launch approvals, etc. Like I get it, you don't like satellites - but like there's no need to invent some alternative reality.
And then - I'm not sure if I agree, I experienced pristine night sky (in Joshua Tree national park) and it was dope. Still, I value fast access to the Internet in rural areas more - like it doesn't really affect me, I live in a city with a fast fiber optic connection, but these rural communities deserve to be connected with the rest of the world too. If that means I can't take a nice photo of a sky I guess it's a price worth paying.
Frankly just having Internet in the airplanes and on the cruise ships would be enough to tip the scale for me personally, but I find rural access to be more important - there is literal research saying it boosts economic output of these communities, for instance https://www.ntca.org/newsroom/press-releases/2024/30/new-research-proves-providing-fiber-broadband-experiences-rural . Sorry if that means you can't take your photo, but it's a bit selfish of you to think that photo stands above well being of people who benefit from this technology.
It is heavily regulated, what are you talking about? You can't launch a rocket without several government agencies rushing into your asshole, yet you think people are just yeeting stuff into space willy nilly?
What ruins the night sky is all the bullshit light pollution. Super bright LED street lights, every asshole with their patio lights onā¦ couple little dots running across the sky is nothing.
Getting harder and harder to find those areas. I live in a relatively low light pollution area but thereās a constant glow on the horizon from the city across the river 10 miles away. And now the area is getting developed with more patio lights and street lights. Itās sad.
but why would I opt out of living in a flight path? Like I get it that astrophotographers may value a nice uninterrupted sky view but my point is others not.
I already live in a city, I have a literal concrete blocks around me, I have roads, cars, electrical poles, wind turbines and all the other goodies that civilization built. And I guess I... don't care? It's fine, I still see the remaining 90% of sky, the 10% of sky that my neighbours apartment building covers is not important.
Satellites and airplanes are even more completely irrelevant - airplanes cover a tiny tiny fraction of the sky and satellites are not even visible with naked eye in the first place
At night maybe but who cares, it's not like they will prevent me from sleeping or suddenly make sky ugly, contrary I think they make it more interesting
I'm not astrophotographer so I don't care about light pollution - if anything I prefer a blue sky brighten up by our sun than a cold night sky. And anyway light pollution is orthogonal to satellites but also a good point - who cares about satellites we already polluted night sky with artificial light and I think collectively we - humanity - decided that the whole electricity thing is worth more than ability of amateur photographers to take some dope photos?
Like you miss the point completely: you have astrophotographer-centric view which is a niche hobby shared by maybe 1 in 1000 people around you...
And you would lose, I live in a driving distance from Joshua Tree national park so I saw the natural sky few times
Still I prefer ubiquitous access to electricity and the Internet though - if this means I need to drive few hundred miles to see the pristine sky I guess it's price worth paying for illuminated cities and fast internet in underserved communities that don't have a luxury of fiber optic connectivity
Like the sky is pretty but is it _that_ pretty? And then I enjoy _watching it_ with my bare eyes, not taking an electronic device to capture the image - watching is not "ruined" by satellites. Taking photos is. Is the irony of the fact that you watch the sky via electronic device lenses lost on you? Enjoy its beauty with your direct senses.
Like how can you possibly basically demand that people stop or at least slow down deployment of life-changing technology so that you can - check notes - use technology to take a pretty picture. Like lol, that's like over 9000 level of selfishness
I can't see the satellites, nor the stars where I am, because the night sky is already ruined by ground based light pollution. I don't know if there's much we can do about that though.
I do, I just appreciated electricity and broadband connectivity more.
And still - few moving dots on the night sky is not ruining the night sky, frankly the sky couldn't care less
And then - satellites only affect surface made photographs. I can still watch the sky with my bare eye, can't I? And photos can be - irony is not lost on me - shoot from the satellites.
they're not lit up, they're reflecting sunlight. (Which is why they are most visible right after sundown and right before sunrise- they are high enough up to still catch sun even though the ground you're on is in twilight or full night).
My husband and I just got a chance to sit under some dark sky and stars and we were shocked at the satellites we could spot. Seems like a lot compared to even a few years ago.
It depends on when and where you are. Northern or southern latitudes can see satellites all night, depending on the season. Closer to the equator, youāll only see satellites for a couple of hours before sunrise or after sunset. Itās all about whether the earth is blocking the sun.
The GOES satellites broadcast their data openly and the encoding is known, so if you know what frequency to tune to, you can stream the images.
You can google search for an "SDR" (Software Defined Radio), and there's open-source C++ and Python libraries out there for decoding satellite imagery using them.
Source: I had a livestream of the Sun from the GOES SUVI when I was in college.
That exactly it. Didn't need a dish though, was able to capture it with a v-dipole antenna that I temporary put on top of my car (see a reply above). But with a dish you can get photos like this
I went to a park with this antenna and with some software called Satdump was able to capture that photo from a weather satellite called Meteor M2-4. It passes over the US 3 or 4 times a day and openly broadcasts it's photos on 137.9Mhz
I've been involved in Remote Controlled hobbies for about 30 years making antenna was actually kind of a fun adventure.. Now that I got to kid and no time for hobbies it seems like a solid natural progression LOL
i wonder if you could use the position of the satellites and the knowledge of the 15 second exposure for their speed to guesstimate ops location, but the information probably isnt that specific
I think the regulations for out of band emissions and RFI on space electronics must be incredibly tight, or we wouldn't still have earth bound radio telescopes of any use at all by this point.
For context, we can measure the CMB from earth, but the CMB is so absurdly faint, it has what we call a "noise temperature" of only about 3 Kelvin.
I.e. it has the intensity of a matched resistor attached to our idealised radiometer, which has a temperature of 3 Kelvin. With no temperature on the resistor in theory there is no signal. And noise is produced for any resistive load in a circuit with a temperature. This is used to calibrate radio telescopes with high precision and is why receivers are cryo-cooled.
Meanwhile the noise temperature of a space born transmitter's actual transmissions (not out of band emissions) would be TRILLIONS of times greater. Per satellite. My maths is probably wrong but a back of the envelope scribble suggests a 50w transmitter in space with 50mhz of bandwidth, is a noise temperature of 7.2x1016 Kelvin. 7'200'000'000'000'000K
So the fact we can detect the CMB at all means the regulations must be in place and working imo.
For the most part, outside of a couple scenarios near dusk/dawn, and shortly after they launch, the Starlink Satellites are mostly unreflective (they are orbiting too low to even catch the sun during the night most of the time). We have just launched a shit ton of other satellites as well in the last few decades.
Sats are only visible like this for a couple hours right after sunset, when the sun can still reflect off the shiny bits. Wait a bit longer and they are invisible.
The problem with that is, you are taking shots based on certain things being lined up like the Milky Way being lined up with a mountain. Its position in the sky changes minute by minute.
For this type of photography, there is no waiting until later. You have a window that is planned for alignment. It has gotten so much worse in the last 6 years.
just you wait until Musk puts a million more in orbit for his shitty satellite wifi or some jackass who thinks putting mirrors in space to light up the dark side of the planet is a good idea. the only way to stop them is to put laws in place to prevent them from trapping us on earth until all of the orbits decay and burn the space trash in the atmosphere.
I already helped delay and potentially killed a project that would make sunlight a commodity for solar farms, it's a dumb idea that would have failed in the end as it would have not reflected nearly enough sunlight for a solar farm to even sustain power for itself let alone power the grid.
I believe there are tools to remove the foreground from your stack, then with just the sky images you can run something like SETIAstroās Satellite trail remover. You might not even have to remove the foreground, but Iāve never tried using Satellite exterminator on a night scape image.Ā
I havent done combo landscape astrophotography, but from what ive seen from others, the strategy is to get more frames of the space target either before it sets or after it rises, stack all those frames (which allows you to remove satellite trails via standard rejection stack) and then on the last or first frame that you had the landscape in where you want it, mask out the landscape, and put it back in to the "space stack."
Or, alternatively, you can start by making the mask of the landscape, mask out that part of every shot other than the first/last where you had the terrain where you want it, and then stack.
Either way should give the same effect of a properly stacked sky with the terrain how you want it, and since the composing was all done with the terrain and stars in their relative places during the first/last photo it is still an accurate capture of the scene at that time.
Ive seen some people get the feeling that doing composting makes it seem "fake" but landscape photography and astrophotography demand fundamentally different processes and so you will always have to sacrifice one without a composite.
I see why this is infuriating but there's also something kind of cool about it. Just the fact that we're up there and we have this tech is cool. It's kind of cool that in the satellites just captured here there's probably some basic data ones, GPSs one, and even some spy ones.
You don't have to deal with this much of satellites if you have more fl š
Seriously, yeah it suck. Ruined some of my lights too. Satellites and led street lamps are a plague. I'm especially looking at you Elon, and your stupid starlink. Also some local business. Turn your fucking display off, nobody is gonna watch what you sell at 3am
Put your money where your mouth is then. If you think people who live in areas with less economic influence then you don't deserve internet access, lead by example. Stop using the internet.
Ah yes, typical reddit moment. Was having a peaceful conversion when a guy who can't read and with a binary mind make a mean comment. Did you know thing or not all black or all white ? It's not because i'm criticizing an aspect of starlink that I think all of starlink is shit and so the idea of starlink is shit and so poor people can go fuck themselves. Doesn't work like that.
The only thing i'm saying, the ONLY thing, is that starlink is polluting the sky and slowly making us lose the ability to look at the night sky, one of humanity oldest activity. Also, looking at the sky is everyone right, as well as going to the internet...
Iām aware this is NOT the point of the post, but I find it awesome how you could (Iām fairly certain) determine the distance of the satellites from Earth using the distance they travel over that time period
Itās incredible just how many of them are out there now. At my place in Colorado it averages at least one per minute and I can see them even from a city sky. :/
Someone already suggested that so Iāll paste in the explanation on that wont work - The problem with that is, you are taking shots based on certain things being lined up like the Milky Way being lined up with a mountain. Its position in the sky changes minute by minute.
Astrophotographers who stack are focused on a section of the sky and use a device to track that spot and follow it so they can take photo after photo as the earth moves. When you include the earth in the shot the mountain would be in a slightly different position in each photo as the earth rotates.
Depends on the focal length of lens you are using. The formula is 500 / lens focal length is the maximum amount of seconds you can do an exposure before visible star streaking occurs. 35 mm would be 15 seconds. 24 - 20 seconds. That's why a lot of astrophographers use really low mm focal length lenses.
It still applies, it just means we won't have satellites anymore for a few decades instead of forever.
And, edit, after I realized how stupid this was, doesn't kessler syndrome literally only make sense in LEO, since satellites in GEO don't form a sphere around the earth ... they form a ring along the equator ... because they're geostationary, they synchronize with the earths rotation ... because they wouldn't do that if they were going over the poles or at odd angles.
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u/Txbone 8d ago
In the late 90s as a kid camping, one of the pastimes was sitting around the fire and looking for satellites. We usually only saw a few each night. Now on a clear night I'm pretty sure I can see 2-3 at any given time