As someone who co-incidentally started dabbling in Astrophotography as a hobby in early 2019 before Starlink launched, back then you literally could capture a single 20-second exposure (on a very wide lens, so no obvious star trail/blur at that focal length due to the Earth's rotation), and get images with no satellites.
Now (and even in 2021 it was getting hard to do that) it's impossible to do that, even with 10 second exposures.
What's needed now is multiple exposures, and merging/integrating them in something like Siril (https://siril.org/) to remove the obvious satellite trails.
However, arguably, integrating multiple exposures, while annoying and time-consuming workflow-wise (i.e. can't just look at images directly from camera, and currently need to convert to TIFF first) is often the better way to get slightly-less-noisy images anyway, and integrate effectively longer exposures without star-trails, so it's a tricky one.
I don't doubt that this is a real problem for astronomers and photographers, but I feel like if you had to work that hard, it doesn't really make your case.
It sounds like you know what you're talking about until one realizes the earth is spinning. Wide field photos can be shot up to thirty seconds depending on the back and lens.
Anything more zoomy than 50mm uncropped you're getting streaks in < dozen seconds. There's a rule of thumb but I don't remember it.
Best course of action is to take a video and let a stacking program deal with it, especially if you use a real telescope.
Also the Sony a7r have like "150,000 ISO " and iirc cost like $3500 with a kit lens. That's a bit above consumer, but I may have mixed up models.
Sure, 10s is certainly long enough to capture Starlink trails, though 10s exposure is not especially long for an astro photo and you would typically want to take longer exposures or stack multiple shorter ones.
For example, my Seestar S50 takes many 10-second photos to form one exposure. I would normally expect to take 1500 10-second exposures or more for a good picture, perhaps over mutiple nights (although this is very different to a wide-field image like this). A Starlink trail would be very visible in any individual frame, often brighter than stars, and I would expect to capture many individual frames containing starlink trails.
I'm waiting for the dystopian SciFi novel now where earth's last survivors blast the escape route through that cloud of satellite rubbish for their Starship (TM), by use of an array of those.
There was a Russian start up planning to do this a few years back. They had actually reached a deal with Pepsi’s Russian operations until the public backlash convinced them to find a different public relations strategy.
https://phys.org/news/2019-01-astronomers-russian-billboards...
That’s so true. I can see it too. The technology to make that must be super fun to work on but please I hope this will never happen. Can you imagine turning the whole sky as a giant pixelated screen to constantly show us ads? That’s as dystopian as it gets. Add to that the probable less than secure software to run it and hackers trying to show stuff up there. That’s something out of a Douglas Adams book. xD
I don't think such a thing could hold together very long, unless it was just a string in a line. Maybe in Morse code?
With multiple launches you could probably get several parallel strings, and use it like a dot matrix printer. It would be a heck of a stunt. But I wouldn't expect it to last for more than one orbit, and only part of the planet could see it.
You can change brightness and color of individual satellites as they move, so they would match the "pixel" they are in now. Just imagine swarm of very small emitting light bugs moving chaotically behind your screen and changing colors as they move from one pixel to an other. The only issue is to make sure that at every moment each pixel has enough bugs to get the required brightness.
You absolutely can see them with the naked eye. Very easy to spot on any given clear night if you know what to look for, especially when they’re moving in a cluster. They don’t look like meteors, far too slow.
Can't tell if you're joking or not, but SpaceX has indeed been collaborating with astronomical observatories to reduce the apparent magnitude (brightness) to ground for Starlink satellites. It's not as if the potential issues weren't apparent and reported on pretty early on, ie, [0] in summer 2020 before the network entered beta. It's not perfect and the period during orbit raising before the satellites enter operational orbits is more challenging, but very significant reductions have been achieved per recs, see for example "Starlink Gen 2 Mini Satellites Photometric Characterization" [1] in 2023 and "The Brightness of Starlink Mini Satellites During Orbit-Raising" [2] in 2024:
>When magnitudes are adjusted to a uniform distance of 1000 km the
means are 4.58 and 7.52, respectively. The difference of 2.94 between
distance-adjusted magnitudes above and below threshold implies that mitigation is
93% effective in reducing the brightness of orbit-raising spacecraft.
So there has been progress, though more may be possible particularly as Starship gives them more mass to work with for less money. That may bring new possibilities to spend mass on "cosmetic" purposes to shade and further reduce magnitude even if it contributes nothing to the core functionality. Same as more mass may allow regulators to feasibly require higher levels of redundancy and more margin for deorbiting in case of issues or at EOL.
Of course, that does leave older unmitigated working sats contributing to light pollution for the rest of their operational lifetimes, though worth noting that one of many major advantages for low-LEO/VLEO operation is that by design such lifetimes are much shorter, and in turn generation refresh will happen more quickly. Perhaps more importantly long term, there aren't as far as I know any actual international standards and agreements towards responsible brightness mitigation (or other issues like disposing of expended upper stages responsibly, standardized end-of-life deorbiting, etc). SpaceX has, for both PR and simple corporate self-interest reasons, been a pretty good actor so far even if they get a lot of attention for being the leading first mega constellation. But I really hope follow on efforts from other players can hit the ground running with magnitude reductions at least as good, and that SpaceX itself continues to improve (or at a bare minimum not backslide).
High bandwidth fully global comms is simply too valuable a capability to really imagine going back at this point. But that's no reason not to pursue reasonable compromise mitigations, and potentially some sort of funds to ultimately create far more orbital telescopes as well as part of the package taking full advantage of what upcoming cheap megalift will make possible.
It's not just optical pollution, the same satellites visible in the article photo over the Pinnacles are leaking radio spectrum noise into the ostensibly "Radio Quiet Zone" of the nearby Murchison that's home to cosmic microwave sensors and one regional part of the developing global SKA radio telescope platform.
This would be real simple to prove, Starlink Satelites downlink on the same band as Satelite TV so you can use the receiver from a dish that downconverts it to something a cheap dongle can handle and put that all inside a grounded, metal box in the bed of a diesel and just record spectrum.
I was under the impression that actual space business people had ways of not leaking RF when flying over.
In new research accepted for publication in Astronomy and Astrophysics Letters, we discovered Starlink satellites are also “leaking” radio signals that interfere with radio astronomy. Even in a “radio quiet zone” in outback Western Australia, we found the satellite emissions were far brighter than any natural source in the sky.
referencing: Detection of intended and unintended emissions from Starlink satellites in the SKA-Low frequency range, at the SKA-Low site, with an SKA-Low station analog (Sep. 2023)
It's an ongoing issue in that Starlink v1.0 leaked and as I recall promises were made that the next generation of satellites would leak less and turn off when over radio quiet zones .. that second gen group have (IIRC) more noise and continuing transmitting over RQZ's.
Not. Often obvious simple solutions are overlooked. For example, NASA spent huge sums of money trying to design a gas gauge that will work in weightless conditions. Until an engineer suggested just having a "reserve" tank that has enough to bring the spacecraft out of orbit.
Another one was NASA spend a lot of money trying to figure out how to not have the Apollo capsule overheat from the sun. The trivial solution was to make it a rotisserie, i.e. slowly rotate it.
>Not. Often obvious simple solutions are overlooked.
I'm not sure I'd say "often" has something like what you offered up been overlooked by SpaceX. We're long, long past the early eras when everything was first getting figured out, and the timescales and costs are totally different. Talking of "obvious", painting something black in orbit has clear enormous thermal implications, and there are aspects of the system that seem necessarily reflective as well (solar panels, optical links and so on) and in turn mitigation requires cascading design decisions. These aren't platinum plated Apollo era programs either. Like, gut check here: do you see ANY space stations or satellites in space, at all, where they "just painted them black"? I don't think it's actually trivial at all.
Anyway main point is yes, it's recognized and yes, it's getting worked on (successfully!), and I hope that will ultimately help pave the road for any other future megaconstellation efforts by showing what's possible.
It isn't that simple, is it? Even if you place the black surface on a spacer (adding mass, might I add), the black surface itself is going to radiate heat back onto the satellite via blackbody radiation. This is always going to create a worse thermal situation unless you can somehow radiate away as much heat as you could with reflections. To see what I mean, check out JWST's thermal shield.
Consider a shaped charge. It seems wild to me that you can direct an explosion with various shapes of the explosive. Perhaps a similar idea can apply to the blackbody radiation - get it to radiate mostly away from the satellite.
Also, the black part will be pointed at the Earth, not the Sun.
It is so polluted you need professional camera gear and processing of hundreds of photos together in order to show it. Get real. Internet access for poor, remote rural areas across the global is more important than convenient timelapse photography.
You are so far from the mark out is staggering. Starlink is priced differently in different countries, and is wildly popular in developing and undeveloped countries.
There's no concept of airspace in space. You have very few avenues to keep a sat restricted to a geographic region. Orbits like geostationary and molniya exist - but they come with their own limitations for many applications.
The concept of “airspace” is purely a legal one and exits only if your country has an air force able to enforce it (see how Israel has absolute control over Lebanese airspace), any country with anti-sattelite technology could at its disposal could declare that their airspace goes up to the geostationary orbit or even above.
Of course it would complicate the use of satellites a lot, but given their military importance it's likely that this will happen at some point when the tech is ready (by tech I mean a way to stop foreign satellites from operating without causing Kessler syndrome)
As someone who co-incidentally started dabbling in Astrophotography as a hobby in early 2019 before Starlink launched, back then you literally could capture a single 20-second exposure (on a very wide lens, so no obvious star trail/blur at that focal length due to the Earth's rotation), and get images with no satellites.
Now (and even in 2021 it was getting hard to do that) it's impossible to do that, even with 10 second exposures.
What's needed now is multiple exposures, and merging/integrating them in something like Siril (https://siril.org/) to remove the obvious satellite trails.
However, arguably, integrating multiple exposures, while annoying and time-consuming workflow-wise (i.e. can't just look at images directly from camera, and currently need to convert to TIFF first) is often the better way to get slightly-less-noisy images anyway, and integrate effectively longer exposures without star-trails, so it's a tricky one.
Auto stakkert
I think it runs off a .mov or other video file, you add black frames, etc.
"Stitching together 343 distinct photos,"
I don't doubt that this is a real problem for astronomers and photographers, but I feel like if you had to work that hard, it doesn't really make your case.
These photos are taken in pitch-black darkness.
You need to take a lot of exposures in order to get the data necessary to even see anything.
This is a single 10sec exposure in the Aussie outback on old consumer gear ( Sony a7iii )
https://www.instagram.com/p/CersLuLBfCz
You don’t need multiples, and you don’t need an overly long exposure.
It sounds like you know what you're talking about until one realizes the earth is spinning. Wide field photos can be shot up to thirty seconds depending on the back and lens.
Anything more zoomy than 50mm uncropped you're getting streaks in < dozen seconds. There's a rule of thumb but I don't remember it.
Best course of action is to take a video and let a stacking program deal with it, especially if you use a real telescope.
Also the Sony a7r have like "150,000 ISO " and iirc cost like $3500 with a kit lens. That's a bit above consumer, but I may have mixed up models.
My camera is not an a7r. I paid $1200 for it used.
The exposure was 10 seconds, so by your own explanation, the spinning of the earth is not a problem ( as you can clearly see in the photo I linked )
An astronomy photo can commonly require hours or even tens of hours of exposure time.
Tens of seconds is about right. It's something like 500/f(mm) in seconds, but you get a feel for what will blur and what won't. Here's an example I shot with a Nikkor 50mm f/1.4 @ 20s: https://www.instagram.com/p/C-mU6iIp0re/?igsh=cm16bWx1cGp3OG...
No, you need to take a long exposure. Multiple exposures may improve the quality but isn’t necessary at all.
If the camera is stationary you must stack multiple short exposures to avoid star trails. You can only take long exposures with an equatorial mount.
Not if your “long” exposure is just 10s long, which is enough to get those annoying starlink trails.
Sure, 10s is certainly long enough to capture Starlink trails, though 10s exposure is not especially long for an astro photo and you would typically want to take longer exposures or stack multiple shorter ones.
For example, my Seestar S50 takes many 10-second photos to form one exposure. I would normally expect to take 1500 10-second exposures or more for a good picture, perhaps over mutiple nights (although this is very different to a wide-field image like this). A Starlink trail would be very visible in any individual frame, often brighter than stars, and I would expect to capture many individual frames containing starlink trails.
You know those airplanes with a banner at the beach?
I can imagine a constellation of satellites writing ads (live) in space using mirrors and other nifty tech.
Unless regulation stops it.
> Unless regulation stops it.
Or a ground-based megawatt IR laser with steerable optics.
Somehow, this sounds quite appealing.
I'm waiting for the dystopian SciFi novel now where earth's last survivors blast the escape route through that cloud of satellite rubbish for their Starship (TM), by use of an array of those.
One can always dream.
There was a Russian start up planning to do this a few years back. They had actually reached a deal with Pepsi’s Russian operations until the public backlash convinced them to find a different public relations strategy. https://phys.org/news/2019-01-astronomers-russian-billboards...
That’s so true. I can see it too. The technology to make that must be super fun to work on but please I hope this will never happen. Can you imagine turning the whole sky as a giant pixelated screen to constantly show us ads? That’s as dystopian as it gets. Add to that the probable less than secure software to run it and hackers trying to show stuff up there. That’s something out of a Douglas Adams book. xD
earliest sci-fi antecedent i know off: https://en.wikipedia.org/wiki/The_Man_Who_Sold_the_Moon
I don't think such a thing could hold together very long, unless it was just a string in a line. Maybe in Morse code?
With multiple launches you could probably get several parallel strings, and use it like a dot matrix printer. It would be a heck of a stunt. But I wouldn't expect it to last for more than one orbit, and only part of the planet could see it.
You can change brightness and color of individual satellites as they move, so they would match the "pixel" they are in now. Just imagine swarm of very small emitting light bugs moving chaotically behind your screen and changing colors as they move from one pixel to an other. The only issue is to make sure that at every moment each pixel has enough bugs to get the required brightness.
I wonder what uncontacted tribes think about starlink
well, if you could observe these things with the naked eye, they might imagine it's similar to a passing meteor.
You absolutely can see them with the naked eye. Very easy to spot on any given clear night if you know what to look for, especially when they’re moving in a cluster. They don’t look like meteors, far too slow.
I saw them myself with my naked eyes! They look like the iss
I’d be more concerned about the light pollution from the city (Perth?) on the horizon.
I'd be more concerned about both. One evil doesn't cancel the other.
Would that be from Perth? Perth is around 180km away. Cervantes and Jurien Bay are nearby towns that could account for that light pollution.
Whataboutism.
Just paint the satellites black?
Yes https://physicsworld.com/a/dark-coated-starlink-satellites-a...
Even better, paint it vantablack
https://en.wikipedia.org/wiki/Vantablack
Can't tell if you're joking or not, but SpaceX has indeed been collaborating with astronomical observatories to reduce the apparent magnitude (brightness) to ground for Starlink satellites. It's not as if the potential issues weren't apparent and reported on pretty early on, ie, [0] in summer 2020 before the network entered beta. It's not perfect and the period during orbit raising before the satellites enter operational orbits is more challenging, but very significant reductions have been achieved per recs, see for example "Starlink Gen 2 Mini Satellites Photometric Characterization" [1] in 2023 and "The Brightness of Starlink Mini Satellites During Orbit-Raising" [2] in 2024:
>When magnitudes are adjusted to a uniform distance of 1000 km the means are 4.58 and 7.52, respectively. The difference of 2.94 between distance-adjusted magnitudes above and below threshold implies that mitigation is 93% effective in reducing the brightness of orbit-raising spacecraft.
So there has been progress, though more may be possible particularly as Starship gives them more mass to work with for less money. That may bring new possibilities to spend mass on "cosmetic" purposes to shade and further reduce magnitude even if it contributes nothing to the core functionality. Same as more mass may allow regulators to feasibly require higher levels of redundancy and more margin for deorbiting in case of issues or at EOL.
Of course, that does leave older unmitigated working sats contributing to light pollution for the rest of their operational lifetimes, though worth noting that one of many major advantages for low-LEO/VLEO operation is that by design such lifetimes are much shorter, and in turn generation refresh will happen more quickly. Perhaps more importantly long term, there aren't as far as I know any actual international standards and agreements towards responsible brightness mitigation (or other issues like disposing of expended upper stages responsibly, standardized end-of-life deorbiting, etc). SpaceX has, for both PR and simple corporate self-interest reasons, been a pretty good actor so far even if they get a lot of attention for being the leading first mega constellation. But I really hope follow on efforts from other players can hit the ground running with magnitude reductions at least as good, and that SpaceX itself continues to improve (or at a bare minimum not backslide).
High bandwidth fully global comms is simply too valuable a capability to really imagine going back at this point. But that's no reason not to pursue reasonable compromise mitigations, and potentially some sort of funds to ultimately create far more orbital telescopes as well as part of the package taking full advantage of what upcoming cheap megalift will make possible.
----
0: "Impact of Satellite Constellations on Optical Astronomy and Recommendations Toward Mitigations" | https://aas.org/sites/default/files/2020-08/SATCON1-Report.p...
1: https://arxiv.org/pdf/2306.06657
2: https://arxiv.org/pdf/2405.12007
It's not just optical pollution, the same satellites visible in the article photo over the Pinnacles are leaking radio spectrum noise into the ostensibly "Radio Quiet Zone" of the nearby Murchison that's home to cosmic microwave sensors and one regional part of the developing global SKA radio telescope platform.
This would be real simple to prove, Starlink Satelites downlink on the same band as Satelite TV so you can use the receiver from a dish that downconverts it to something a cheap dongle can handle and put that all inside a grounded, metal box in the bed of a diesel and just record spectrum.
I was under the impression that actual space business people had ways of not leaking RF when flying over.
It's been proven by several teams already, eg:
from: https://theconversation.com/starlink-satellites-are-leaking-...referencing: Detection of intended and unintended emissions from Starlink satellites in the SKA-Low frequency range, at the SKA-Low site, with an SKA-Low station analog (Sep. 2023)
https://arxiv.org/abs/2309.15672
It's an ongoing issue in that Starlink v1.0 leaked and as I recall promises were made that the next generation of satellites would leak less and turn off when over radio quiet zones .. that second gen group have (IIRC) more noise and continuing transmitting over RQZ's.
> Can't tell if you're joking or not
Not. Often obvious simple solutions are overlooked. For example, NASA spent huge sums of money trying to design a gas gauge that will work in weightless conditions. Until an engineer suggested just having a "reserve" tank that has enough to bring the spacecraft out of orbit.
Another one was NASA spend a lot of money trying to figure out how to not have the Apollo capsule overheat from the sun. The trivial solution was to make it a rotisserie, i.e. slowly rotate it.
>Not. Often obvious simple solutions are overlooked.
I'm not sure I'd say "often" has something like what you offered up been overlooked by SpaceX. We're long, long past the early eras when everything was first getting figured out, and the timescales and costs are totally different. Talking of "obvious", painting something black in orbit has clear enormous thermal implications, and there are aspects of the system that seem necessarily reflective as well (solar panels, optical links and so on) and in turn mitigation requires cascading design decisions. These aren't platinum plated Apollo era programs either. Like, gut check here: do you see ANY space stations or satellites in space, at all, where they "just painted them black"? I don't think it's actually trivial at all.
Anyway main point is yes, it's recognized and yes, it's getting worked on (successfully!), and I hope that will ultimately help pave the road for any other future megaconstellation efforts by showing what's possible.
I've been designing things my entire professional life, and yes, engineers overlook the obvious all the time (me too!).
I always look for simpler ways, and often enough find them.
It should also be possible to de-orbit obsolete satellites faster if they can at end-of-life deploy a "sail" that will cause more drag.
Eddy-current-generating tethers seem a more practical option:
<https://www.colorado.edu/faculty/kantha/sites/default/files/...>
(A plot point in Neal Stephenson's Seveneves.)
And then we have to consider what’s the effect of all those vapourised metals on the atmosphere
Might then have a lot of overheating satellites :)
Put the black surface an inch away from the satellite, supported by standoffs. That'll keep the heat away from the satellite.
Also, the black surface only needs to be on the Earth facing side.
It isn't that simple, is it? Even if you place the black surface on a spacer (adding mass, might I add), the black surface itself is going to radiate heat back onto the satellite via blackbody radiation. This is always going to create a worse thermal situation unless you can somehow radiate away as much heat as you could with reflections. To see what I mean, check out JWST's thermal shield.
Consider a shaped charge. It seems wild to me that you can direct an explosion with various shapes of the explosive. Perhaps a similar idea can apply to the blackbody radiation - get it to radiate mostly away from the satellite.
Also, the black part will be pointed at the Earth, not the Sun.
To complicate it further I thought that some of the military sats had rotating black panels to shield them from ground visibility?
You have to crack a few eggs to make an omelette. The benefits of satellites seem worth the cost, at least in the foreseeable future.
It is so polluted you need professional camera gear and processing of hundreds of photos together in order to show it. Get real. Internet access for poor, remote rural areas across the global is more important than convenient timelapse photography.
a) You can take these photos with a smart phone.
b) In Australia we are rolling out fibre to rural areas and are testing 10Gb plans. Starlink will never come close to those speeds.
Poor, remote rural people need influencers to tell them which lambo to buy too.
Starling et al are about profit, ignoring their impact to humanity
And they profit because people need the valuable service they provide.
I doubt astronomy is as important as providing good internet access to millions of people in low-service areas around the globe.
The poor can't afford it. Military use is the only way Starlink will stay afloat.
You are so far from the mark out is staggering. Starlink is priced differently in different countries, and is wildly popular in developing and undeveloped countries.
A startup idea: launch satellites to capture clean night sky photos, with tiered subscription model of course.
Startup idea: launch anti-satellite satellites to de-orbit other satellites littering your airspace.
There's no concept of airspace in space. You have very few avenues to keep a sat restricted to a geographic region. Orbits like geostationary and molniya exist - but they come with their own limitations for many applications.
The concept of “airspace” is purely a legal one and exits only if your country has an air force able to enforce it (see how Israel has absolute control over Lebanese airspace), any country with anti-sattelite technology could at its disposal could declare that their airspace goes up to the geostationary orbit or even above.
Of course it would complicate the use of satellites a lot, but given their military importance it's likely that this will happen at some point when the tech is ready (by tech I mean a way to stop foreign satellites from operating without causing Kessler syndrome)
The Kessler syndrome will take care of it
HN Startup idea: train a gen. AI on NASA photos and sell custom photos /s