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 think it runs off a .mov or other video file, you add black frames, etc.
I can imagine a constellation of satellites writing ads (live) in space using mirrors and other nifty tech.
Unless regulation stops it.
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.
Or a ground-based megawatt IR laser with steerable optics.
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.
I’m fine with putting dots in the sky as a necessary side effect of providing some sort of useful service. Worldwide connectivity seems worth making astronomical observations a bit harder. But visual pollution for its own sake should be harshly discouraged.
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.
You need to take a lot of exposures in order to get the data necessary to even see anything.
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.
https://www.instagram.com/p/CersLuLBfCz
You don’t need multiples, and you don’t need an overly long exposure.
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.
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 )
(This is a simplification, there are many types of noise including shot noise and thermal noise, but in general this is the rule of thumb you use)
I was going off memory, and with 50mm, it looks like 10 seconds is about when you start to get streaks, assuming no cropping. I have cropped sensors so even with a 10mm lens i can only do 12-15 seconds. I have a barn door tracker, and i know how to use https://www.autostakkert.com/
you need to have black frames for it to work, and ideally a lot of them (iirc at least a half dozen if not more) - because this is how the stacker knows which pixels are noisier than other ones, and also what the thermal noise of the sensor "looks like", at least the smarter stackers use it that way. you take a bunch of pictures with the lens cap on in a dark room at around the temperature you're gunna use it at.
real amateur astrophotography is done with CCD cameras, usually monochrome with filters (or a filter wheel), done in video mode, and the frames are processed after the fact. It takes hours with clear skies to make a decent deep field astrophotograph.
Some random search result:
I believe 30s might be more appropriate for star trails which makes satellite trails oh so much more obvious. But that means a 2-3 hour session of 2 exposures per minute.
I also used to take hundreds of photos in meteor season - and having to diff between meteors and satellites was quite time consuming.
Also, the black surface only needs to be on the Earth facing side.
Also, the black part will be pointed at the Earth, not the Sun.
If it's just an asymmetric shape, with different material surfaces pointed in different directions, than that of course is permitted.
https://en.wikipedia.org/wiki/Kirchhoff%27s_law_of_thermal_r...
PS I haven't done thermo in nearly 50 years!
That's: a cavity that's a thin wedge in between two slightly angled plates, where the interior surface coating is partly emissive, and partly infrared-reflective—it can reflect the thermal radiation it emits. That means specular reflections, following geometric optics, so it works like a horn for light—beams it out the sides in a narrow cone.
(.pdf) https://ttu-ir.tdl.org/server/api/core/bitstreams/71aee1e9-3...
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>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.
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0: "Impact of Satellite Constellations on Optical Astronomy and Recommendations Toward Mitigations" | https://aas.org/sites/default/files/2020-08/SATCON1-Report.p...
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.
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 always look for simpler ways, and often enough find them.
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)
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.
Sounds like the ITU-R messed up, regardless of why. starlink is 28% of the EIRP the ITU specified. And the "newer generation are a factor of 12 fainter".
We're talking micro. watts. of Effective Isotropic Radiating Power. with 0dBi antennas (unity gain).
I don't understand why they're using those oddball frequencies, but i haven't paid attention to band allocations in a long time. 159.4MHz is Land Mobile band plan - "business band 2 meters", and oh, 137.5 is "SPACE OPERATIONS". I almost want to guess that the 159.4 is a spur of something down around 39.9MHz, fourth harmonic or something. I don't see anything that would let starlink radiate there, unless they change frequencies over countries. Furthermore, it doesn't seem like the 159.4MHz signals will be a detriment to the facility in question, but merely possibly impinge on radio-astronomers.
I understand that these arrays are so sensitive that the RF they collect and process in the career of a scientist there is roughly equal to a cricket chirping once. or something. But microwatts are real tiny, too. Should be possible to put a notch filter at 137.5, or request space businesspeople to do intra-satellite on some other frequency.|
in fact, business idea: aim a yagi array where the satellites are as they pass over, can be done programmatically, or reactively - at least 4 sensors however far from the facility monitor the starlink downlink frequencies (not 137.5 and 159.4, but the ku band ones) - and then aim at the satellite.
I'll build it out with crap i have in my shed to prove it works if anyone is interested. If you know a satellite is in your second of sky, and you monitor, specifically, the 137.5 frequency with a separate, real sensitive antenna array, you can just drop the IQ/whatever from the radios for that timeframe.
This isn't rocket science, QRM and QRN will plague us forever. Thanks, Marconi.
<https://www.colorado.edu/faculty/kantha/sites/default/files/...>
(A plot point in Neal Stephenson's Seveneves.)
https://science.nasa.gov/solar-system/meteors-meteorites/fac...
b) In Australia we are rolling out fibre to rural areas and are testing 10Gb plans. Starlink will never come close to those speeds.
I doubt astronomy is as important as providing good internet access to millions of people in low-service areas around the globe.
In some way this reminds me of living in SF back in 2015, and all the arguments over the towers going up in soma. “No one wants the Manhattanization of the city” was accepted fact on both sides. Yet that wasn’t an obvious fact to me at all, and I could never find an argument in support of this ‘fact’.
Can someone enlighten me here?
"....Rozells’ composite visually echoes pleas from astronomers, who warn that although satellites collect essential data, the staggering amount filling our skies will only worsen light pollution and our ability to study what lies beyond. Because this industry has little regulation, the problem could go unchecked....."
What is light pollution \* Glare is the bright and uncomfortable light shining directly to the observer that interferes with your vision.
\* Light trespass is the unintended spill of artificial light into other people’s property or space and often becomes a source of conflict.
\* Skyglow is the brightening of the night sky from human-caused light scattered in the atmosphere.
Reflected sunlight from a human object spilling light into an environment that would otherwise not have that reflected sunlight is very much in the spirit of light pollution.
It's certainly seen as such by astronomers.
Starlink satellites pollute the night sky with both reflected sunlight and intended and unintended radio spectrum noise.
Manmade objects that inject light into an otherwise dark sky fit the category of skyglow, reflected sunlight tends to be sharper and less diffuse than atmospherically scattered ground lighting .. it's all extraneous human caused pollution from the PoV of telescopes.
Now imagine the probability of the debris hitting other satellites and causing even more debris.
Finally, compare how many satellites have been launched in the past 5 years versus the rest of history.
I feel like when <something> is the sky, potential counterpoints can't be that far. For a direct response to your question: the sky and the stars beyond have been present and visible to every human, throughout all of history- how might different people feel about it becoming obstructed? Philosophically? Emotionally? Pragmatically?
The following types of people might feel strongly about this for some reason or another- I feel like steelmaning hypothetical opinions they might have is a really enriching thing to do.
- Photographers / enthusiasts
- Astronomers / enthusiasts
- Those who enjoy nature
I personally have a mixed opinion, probably leaning towards alignment with the above groups, but I can also steelman the thought processes of those who'd think this is cool or fascinating (because of course, it is!)
I'm not trying to convince you of something about the post subject here; The rhetorical questions above are not intended to be read as "how don't you understand this and agree with me", but instead "how/why did these potential viewpoints not find you?" The lack of mention of any other viewpoint comes off as almost poor-faith or naivete.
In the SWE community, people place a lot of emphasis on attempting to find solutions to a problem yourself first, before asking a question (and detailing what you've tried/explored already) to a community. With that mentality, it irks me when I see comments that don't seem to apply the same rigor to rhetorical discussions.
At the risk of being overtly snarky, could you really not conjure anyone that might have an opposing viewpoint?
But a negative viewpoint can't be that hard to see, right?
Sorry, but the ship has sailed. Fix your problems in software maybe.
> - Astronomers / enthusiasts
Every Starship launch should offer ride-share for a space based observatory. Astronomy will only improve with space based telescopes. Yes, spacecraft are expensive but so are Earth based observatories, but how does it look with launch cost removed from the equation?
> - Those who enjoy nature
Generally can't see the satellites with the naked eye. Should probably concentrate on not walking into a hole / body of water / off a steep precipice.
This complaint about the aesthetics of the night sky is the wimpy enemy of progress. Imagine bronze / iron age people up in arms because suddenly the sea is full of fishing boats and merchant vessels. Or people up in arms because farmland has spoiled the view of forests.
Yes, I think this stuff looks nice without man-made things. I enjoy the night sky. I also enjoy being able to eat and utilize modern technology. There will come a day when spacecraft coming and going will be as routine as we see airplanes now, so our descendants will have that to complain about next, until it becomes as pointless to complain about as the asphalt roads that have lead to and from or houses.
Space based technology will make life better for all of humanity just like every technology that has come before it. The genie is out of the bottle and isn't going back in.
The Webb Space Telescope cost $10 billion, and has a 6.5 meter mirror. With the launch cost removed, it cost $9.5 billion.
The Extremely Large Telescope is located on Earth, costs a little over $1 billion, and has a 39 meter mirror.
The idea of completely replacing ground observatories with orbital ones is so infeasible it's not really worth discussing. If satellite pollution grows so extreme they can no longer function, those capabilities will simply be lost.
We have the technology to put observatories in orbit, where satellite "pollution", light pollution, atmospheric effects, etc. all become significantly less problematic. Maybe that should be our focus, rather than on shaming satellite constellations for doing essential work?
Image is stacked from multiple images during sunset/sunrise when satellites are most visible because of sun position to observer. Photographer is in dark while satellites are lighted by direct sunlight.
During night, its barely visible.
kofianon•2w ago
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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)
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