Astronomers Find Growing Number of Starlink Satellite Tracks (arstechnica.com) 112
A team of astronomers has used archival images from a survey telescope to look for Starlink tracks over the past two years. Over that time, the number of images affected rose by a factor of 35, and the researchers estimate that by the time the planned Starlink constellation is complete, pretty much every image from their hardware will have at least one track in it. Ars Technica reports: SpaceX's Starlink Internet service will require a dense constellation of satellites to provide consistent, low-latency connectivity. The system already has over 1,500 satellites in orbit and has received approval to operate 12,000 of them. And that has astronomers worried. Although SpaceX has taken steps to reduce the impact of its hardware, there's no way to completely eliminate the tracks the satellites leave across ground-based observations. [...] In response to complaints from the astronomy community, SpaceX put visors on later generations of Starlink satellites. The research team was able to compare the visibility of these different generations and found that the visors worked -- satellites with visors dropped in brightness by a factor of roughly 4.6 (the precise number depended upon the wavelength). The visibility, however, was still higher than the target set at a workshop that was meant to address this issue.
Because these tracks are small and software already identifies and handles them, they don't have much of an effect on observations. The researchers estimate that, at present, there's only a 0.04 percent chance that a rare event will be missed because it coincides with a track. But because the problem is most acute in twilight observations, it's more likely to impact searches for objects within the Solar System. This would include comets and asteroids -- including asteroids that originated around other stars. But again, the problem is likely to get worse. SpaceX already has approval to increase the number of Starlink satellites to well over 10,000; the authors estimate that at 10,000, every image at twilight will likely contain a Starlink track. SpaceX has indicated it would eventually like to boost the numbers to over 40,000 satellites, at which point all twilight images are likely to have four tracks.
And SpaceX isn't the only company planning on this sort of satellite service. If all the companies involved follow through on their plans, low Earth orbit could see as many as 100,000 of these satellites. Overall, the picture is mixed. The ZTF's main mission -- to pick out rare events caused by distant, energetic phenomena -- is largely unaffected by the growing number of satellite tracks. And because the percentage of events is currently small, tripling the number of satellites won't have a dramatic impact on observations. But a secondary science mission is already seeing a lot of light contamination, and matters are only going to get worse. The findings have been published in the journal Astrophysical Journal Letters.
Because these tracks are small and software already identifies and handles them, they don't have much of an effect on observations. The researchers estimate that, at present, there's only a 0.04 percent chance that a rare event will be missed because it coincides with a track. But because the problem is most acute in twilight observations, it's more likely to impact searches for objects within the Solar System. This would include comets and asteroids -- including asteroids that originated around other stars. But again, the problem is likely to get worse. SpaceX already has approval to increase the number of Starlink satellites to well over 10,000; the authors estimate that at 10,000, every image at twilight will likely contain a Starlink track. SpaceX has indicated it would eventually like to boost the numbers to over 40,000 satellites, at which point all twilight images are likely to have four tracks.
And SpaceX isn't the only company planning on this sort of satellite service. If all the companies involved follow through on their plans, low Earth orbit could see as many as 100,000 of these satellites. Overall, the picture is mixed. The ZTF's main mission -- to pick out rare events caused by distant, energetic phenomena -- is largely unaffected by the growing number of satellite tracks. And because the percentage of events is currently small, tripling the number of satellites won't have a dramatic impact on observations. But a secondary science mission is already seeing a lot of light contamination, and matters are only going to get worse. The findings have been published in the journal Astrophysical Journal Letters.
does anyone know (Score:2)
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They're estimated to cost between $250k and $500k but SpaceX hasn't released exact numbers. The newer generation, with laser inter-satellite comms, is more expensive. It's hard to pin down given that there will have been large upfront development costs to be amortised over a much larger constellation than has yet been launched.
Space (Score:1)
Telescopes ought to all be in space or on the moon. Astronomers should allow SpaceX to succeed so that it can launch telescopes into space, where they belong. Having telescopes on Earth is stupid given how shitty the atmosphere and all the shit that happens in our atmosphere .. everything from clouds to random atmospheric distortion.
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Telescopes ought to all be in space or on the moon....
Along with nature preserves and national parks...
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Telescopes ought to all be in space or on the moon....
Along with nature preserves and national parks...
Along with Ol Muskie's cult followers.
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Telescopes ought to all be in space or on the moon. Astronomers should allow SpaceX to succeed so that it can launch telescopes into space, where they belong
So you you're just saying a big "fuck you" to every amateur astronomer who isn't an astronaut, and doesn't have a nation state sized space program backing them up?
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So you you're just saying a big "fuck you" to every amateur astronomer who isn't an astronaut, and doesn't have a nation state sized space program backing them up?
High school science clubs have put satellites in orbit. The cost is dropping rapidly.
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You could launch your own cubesat space telescope. Have fun packing everything into a 10x10x10cm size (4x4x4 inches) and 1.3 kg (3 pounds). Fortunately, 100mm sized optics (lenses or mirrors) are inexpensive. Unfortunately, the launch cost goes into the $50,000.
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Telescopes ought to all be in space or on the moon. Astronomers should allow SpaceX to succeed so that it can launch telescopes into space, where they belong
So you you're just saying a big "fuck you" to every amateur astronomer who isn't an astronaut, and doesn't have a nation state sized space program backing them up?
Or we could just stop whining and apply a damn software filter to your camera to cut out any signal coming from sources moving faster than $WHATEVER across the field of vision. But guess that would be too easy a solution.
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Which would still suck for identifying any natural fast moving nearby objects
I think bird watchers and planespotters are somehow going to cope.
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Those objects are close enough to the ground that they aren't going to reflect the sun's light to you at twilight or before dawn and as such are not going to produce light trails.
I realize the importance of Starlink, but let's not pretend that as it is increasingly deployed, it will fuck up ground-based astronomy for a shit ton of people.
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Is waiting an extra hour before observations a big deal? Or even seeing the satellites across the view once in a while.
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Thankfully, the Starlink satellites are close enough to the ground that they can be easily obscured by earth's shadow, and only the hours near sunrise and sunset are really affected by this , but to answer your question, it can be, depending on the area of the sky you may have been photographing.
If it was really only every once in a while, it might not be that a big deal.
But as the numb
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Thankfully, the Starlink satellites are close enough to the ground that they can be easily obscured by earth's shadow, and only the hours near sunrise and sunset are really affected by this , but to answer your question, it can be, depending on the area of the sky you may have been photographing.
If it was really only every once in a while, it might not be that a big deal.
But as the number of Starlink satellites increases, it will eventually get to a point where it has become all but impossible to take photos of the twilight sky without getting a dozen (or more!) skylink satellites in view.
I wish I could propose a solution for this, but I don't have one. Preprocessing the photos to remove objects that are moving fast enough might help if you are only interested in the star trails, for example, but if you were, say, wanting to catch shooting star trails as well, those could end up undesirably getting filtered out.
Yes, that does involve some of a bit more complicated logic like "if it's moving at above Earth's escape velocity it's a meteor, if not, it's satellite", "if it changes brightness its a meteor, otherwise it's a satellite", and most importantly "if it matches one of the (publicly known) orbits of satellites, it's a satellite". Still, firmly within the technical capabilities of humankind.
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Objects can be moving much faster than escape velocity and still appear to be moving at the same speed across the sky if they are simply correspondingly further away from the observer.
L An object (not a falling star, obviously, but perhaps a small asteroid passing close to the earth) might be say twice as high as Starlink for example, but moving at approximately twice the velocity and thus have an almost indiscernible speed difference to the satellite as seen from the ground.. Any automated filtering s
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Objects can be moving much faster than escape velocity and still appear to be moving at the same speed across the sky if they are simply correspondingly further away from the observer.
L An object (not a falling star, obviously, but perhaps a small asteroid passing close to the earth) might be say twice as high as Starlink for example, but moving at approximately twice the velocity and thus have an almost indiscernible speed difference to the satellite as seen from the ground.. Any automated filtering system would not be able to discern the difference.
However, my point remains.
As Starlink is increasingly deployed, it is going to at the very least greatly complicate if not actually fuck up ground-based astronomy near the hours of sunset and sunrise.
Yes, my rule number one is not completely foolproof, hence rules number 2 and particularly 3 that easily deal with this scenario.
Re: Space (Score:2)
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IT ONLY HAPPENS AT TWILIGHT! Amateur astronomers can wait an hour or two past sunset and do their observation.
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So you you're just saying a big "fuck you" to every amateur astronomer who isn't an astronaut, and doesn't have a nation state sized space program backing them up?
Uhm. Yes? The days of amateur astronomers being the first to find previously unrecognized comets and asteroids are fading extremely rapidly, and it's not because of Starlink. Nation-state space programs have built full sky survey telescopes that amateurs can't hope to compete with. As such, amateur astronomers are strictly hobbyists, doing it for fun. They can handle a few streaks in their images. Hell, futzing around with software is half of what even an amateur does these days. Streak removal is on
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There is a small subset of the population that want the "hands-on" approach (i.e. taking a mobile telescope somewhere and losing a night exploring the night sky and taking pictures, then losing a day selecting and composing pictures when something better is basically free to download in a second.
So no, having telescopes in space or on the Moon is not the same thing. It's the difference between launching rockets and the Kerbal Space Program, between skiing and Microsoft Motionsports Kinnect.
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There are also people who enjoy looking at the sky live. Through an eyepiece. Granted, this way you are less likely to be annoyed by a starlink satellite. But my point is stargazing has a value even without astrophotography or scientific discoveries.
Some countries and states take measures to reduce light pollution for that reason.
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I'm quite certain Elon's PR team is lining up a joint venture with their marketdroids to sell rides for telescopes in the near future.
Kessler Syndrome (Score:2)
Telescopes ought to all be in space or on the moon.
Hate to say this, but... (Score:5, Interesting)
Look, I love science coming up with new and fascinating stuff as much as any other nerd.
But I'm also a pragmatic... Looking through all the dirt and water in our atmosphere is a bit stupid to begin with. I get it, it was too expensive to bring telescopes into orbit... James Webb cost what, 10 billion all said and done?
I think, however, we're at a tipping point. Instead of "whining" about Starlink getting in the way, astronomers should hope that SpaceX becomes profitable on a level like Facebook or Google... Just imagine if it took only a fraction of Webb to bring hardware into space. Imagine even multi millionaires having the means to deploy telescopes in space or on the far side of the moon that could be rented on an hourly basis like mainframes could back in the day. The more of them the cheaper it would be.
Am I the only one who thinks that maybe what is to this field of science's detriment could give it wings ten years down the road?
Re:Hate to say this, but... (Score:5, Informative)
It only means you have to schedule your observation to late night. Starlink satellites are only visible around twilight or dawn. Wait a couple hours after sunset and you wont see them. They shine because they reflect sunlight.
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Those observations looking for inner-system asteroids, tho.
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Anything serious should be in space or on the moon. Especially asteroid hunting telescopes.
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You're joking, right?
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That's true of the current constellation - you only lose 10-20% of your potential observing time. But they're the low altitude fleet - there's more coming and they'll be higher up and thus visible much deeper into the night.
Not to mention Starlink isn't the only constellation being built out...
Re: Hate to say this, but... (Score:2)
Re: Hate to say this, but... (Score:1)
Worth noting, a *lot* of the cost of James Webb was the cost of launching it, and the cost of making sure that it worked flawlessly first time. There was only one reasonable chance to get it right. If, when it was designed, SpaceX had been able to throw hundreds of sats up quick fire, I dare say they would have designed it as a constellation of smaller sats, where 10% could fail and still have an excellent telescope. That would have made it *much* cheaper.
SpaceX will be able to revolutionise astronomy.
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You can't do what the James Webb is doing by using more satellites, so that's a completely irrelevant point, unfortunately.
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Additionally, spacex doing a bunch of launches that can toss things into LEO is a whole different matter than getting something to L2.
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Yes, but you could build and launch two cheaper JWSTs, with equal chances to have one working flawlessly.
And the Starship will allow the launch of a larger mirror that doesn't need to "unpack", or an even larger mirror that needs to unpack itself. The 6.5 meters mirror of JWST had to fit into a 4.57 meters wide Ariane 5 payload fairing. The Starship will (probably) have a 9 meter wide payload fairing, fitting a 9 meter mirror (not folded), or a 12+ meter mirror folded like JWSTs. A 12+ meter antenna could s
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What makes you think that? In general, telescopes with large mirrors can be replaced by clusters of telescopes with small mirrors to gain the same results. That's why you see absolutely massive arrays of radio telescopes - because they're creating a radio telescope with a gigantic aperture.
A cluster of smaller satellites absolutely could do the job, not just that, but they could do it *better*.
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Launch was about $250 million out of a $10 billion project, not really a significant portion.
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Yes - but Webb was built to not fail, because launching things to L2 is (was) hard, and that meant that they could only launch one sat once. With starship in place, it will be trivially easy to launch a ton of satellites to L2, which will mean that it won't require such a perfectly engineered telescope.
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We are in a golden age of astronomy where really good equipment is quite affordable. Software processing has turned fairly basic instruments into very capable ones. Amateurs can and do regularly make interesting discoveries, as well as it being a very rewarding hobby.
Replacing that with renting an hour on a space telescope is not an adequate replacement. You need to build up to the level where you can do something useful with a space telescope, which means many many hours of practice on lesser equipment.
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...and having a blip that turns up only during dawn or twilight according to another user completely negates the possibility of doing that in the future?
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We are in a golden age of astronomy where really good equipment is quite affordable. Software processing has turned fairly basic instruments into very capable ones. Amateurs can and do regularly make interesting discoveries, as well as it being a very rewarding hobby.
Replacing that with renting an hour on a space telescope is not an adequate replacement. You need to build up to the level where you can do something useful with a space telescope, which means many many hours of practice on lesser equipment.
This. Ancient land based telescopes have been fitted with modern processing equipment and are doing yeoman work.
In addition to the reality that it is difficult to get time on a few space based telescope. It is a lot easier to get time on, and get physical access to a ground based telescope. New equipment for new studies can be placed on, and worked on. The wild effort to fix the Hubble is an example of what you have to look forward to if there is a problem, and the things need repaired.
LEO thousands of
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We are in a golden age of astronomy where really good equipment is quite affordable. Software processing has turned fairly basic instruments into very capable ones. Amateurs can and do regularly make interesting discoveries, as well as it being a very rewarding hobby.
Yes. That software processing you speak of is very capable of filtering out irrelevant data -such as satellites passing thru the field of view.
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Discovering Earth Killer Asteroids early or Netfli (Score:1)
What's important? Discovering Earth Killer Asteroids early enough or Netflix?
The worlds richest Capitalist (or second richest) is spoiling our night skies for profit.
The destruction and pollution of humans is now graduating to space.
We've reached the point where Consumption and Greed (Profit) are more important than learning and discovering the truth about our natural universe..
It speaks volumes about humanity... and how short sighted and selfish we all are.
You have been brain washed... to accept your Capi
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Tesla Fanboy 2015: There's no way Starlink will interfere with terrestrial astronomy! Musk is too smart to let that happen!
Tesla Fanboy 2022: Well of course Starlink interferes with terrestrial astronomy! We always knew that would happen! Telescopes should be in space, launched by that really smart Elon Musk!
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Looking through all the dirt and water in our atmosphere is a bit stupid to begin with. I get it, it was too expensive to bring telescopes into orbit.
Well then, it's not stupid. It's an eminently sensible practical tradeoff. Space is big [citation needed], so big that amateur astronomers within an amateur budget can still make discoveries. There's an absolute load of stuff we can still discover from earth looking through the atmosphere. Sure there's plenty of stuff for which we can't which is why we have J
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Space is big [citation needed]
Citation provided.
https://www.goodreads.com/quot... [goodreads.com]
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Instead of "whining" about Starlink getting in the way, astronomers should hope that SpaceX becomes profitable on a level like Facebook or Google...
And how exactly will that happen?
Some sort of forcing people onto StarLink? Performance wise, it ain't all that. It has better latency than Satellite internet that is higher in orbit, That's about it. As well - kinda interesting that the antennas on earth have to have heaters to remove Ice and snow. That's a testimony to a big problem.The signal is deeply attenuated by water. Radio waves of those frequencies are subject to that. It's a measurable phenomenon, and Satellite television is subject to black
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In areas that make sense for Starlink - there are simply not as many potential customers. In areas with sizable populations, there are clearly better options.
Something around 80% of the USA does not have more than one ISP option, and that one ISP is going to be Spectrum/Charter or Comcast.
I'm in no hurry to switch from my 3 GB/sec Comcast to 92.7 MBit/sec fastest speed of Starlink.
Those are not "better options" when compared to a kick in the teeth, let alone another option for Internet connectivity.
Perhaps you don't consider a city with a 1.5 million population "sizable", but most people would call it that.
If the obviously much slower speed of Starlink is preferable, have at it. Some of us find that speed not adequate.
Most of us have to put up with whatever highway robbery our one ISP throws at us, or fall back to the dark ages of the 80s
I can't believe that other, already underserved countries, would not find cheap satellite service a valid option either.
If all of that combined is or isn't enough for starlink to profit is still an open question, but I think you're vastly underestimating the actual size of their market.
If you had my speed service, would you switch to VDSL speed service, just because you love Musk or something? Because you aren't doing it for better service.
But seriously, Starlink is closer to VDSL speeds than my Comcast speed. Maybe Elon should look into internet on smartphones? Maybe someone co
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*sigh*
That's not how this works. That's not how any of this works.
Only a small fraction of Webb's $10 billion cost was launch and delivery. The vast majority of that was spent first developing the technology and then buildin
Koyaanisqatsi (Score:2)
"If we dig precious things from the land, we will invite disaster."
"Near the day of Purification, there will be cobwebs spun back and forth in the sky."
"A container of ashes might one day be thrown from the sky, which could burn the land and boil the oceans."
We have the first, Starlink qualifies for the second, and with current technology the third "might" be possible
burn the land and boil the sea... (Score:2)
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imagine being so soft brained that you think bringing up some stupid magical prophecy is relevant. Shut up and let the grownups discuss the issue.
Re: Koyaanisqatsi (Score:2)
Ground & air based connectivity... (Score:3, Interesting)
Why are we putting thousands of pieces of future debris in space when we have the capability to run cable (copper or optical), construct microwave links & such? It won't get in the way of astronomers, won't be a risk to spacecraft going up or in orbit and should easily be cheaper. Or is it about the bragging rights of how many thousands of spacecraft you can have up there?
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it's not future debris. any inactive Starlink satellite de-orbits and burns up in the atmosphere after a couple years.
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They're in LEO, so the chance they end up as 'space debris' is extremely low. Once they reach end of life, they'll just de-orbit and burn up.
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As a reply to myself... Unless you have idiots shooting missiles at satellites, causing other satellites to break up and so on...
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That's... not how this works.
Any satellite that loses the capability to de-orbit becomes space debris for the length of time it takes them to de-orbit. Right now, they're at an altitude where it will take 5-8 years for them to naturally decay. The 1200km constellation though... orbital lifetime at that altitude is measured in centuries.
And keep in mind, Star
Re:Ground & air based connectivity... (Score:5, Informative)
should easily be cheaper
If it were cheaper to cable everyone's homes they'd do it. That's everyone, and there are a surprisingly large number of people who live a surprisingly long cable run from the nearest internet link. Turns out, it's cheaper to do these people via satellite. Then there are cruise ships and planes that would like low-latency, high-speed internet too, and you can bet the military is very interested.
With cable runs, don't forget you don't just have to lay the cable initially, you also have to go out and fix it every time someone digs it up somewhere or something takes out a pole it's on. Maintenance is expensive.
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Satellites are not affected by backhoes like ground-based communication infrastructure could be.
Tonga has very spotty internet connectivity right now, Starlink could help with that.
Also there are "out of nowhere" places where the cable companies can't be bothered to run cable.
It might be an US thing - the cable companies created a large enough market that only wants cheap and reliable Internet access, and for many of them Starlink is the cheaper, faster and more reliable option. Also, considering the speed
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Among the other reasons, it's faster than fiber optic cables. Light in a vacuum travels twice as fast as it does through fiber optic cables. Cheaper to deploy and lower latency.
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Because with cable you can still unplug it or take an axe to it or go live in a cabin in a forest on a mountain if you want to get away from the neuralink/iot skynet matrix? I hear the red pill's effects degrade over time (accelerated by 5G) and has to be retaken periodically...
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For me it's honestly about getting good high speed internet to remote locations, such as where I live. Starlink has worked out very well for us. I'll happily pay Musk $100 a month for what has turned out to be a low-latency, high speed connection. The only previous internet connections we had before were ground-based wireless which were very flaky (4 Mbit/s down, 0.2 up), and over-subscribed. Starlink is over 100 down, maybe 30 up. It remains to be seen whether over subscription will also kill Starlink,
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honestly, you are partially correct. Right now, rural internet access is pretty horrible.
on one hand you have traditional sat companies (hughes, viasat - vilesat) and the like. by virtue of the orbit their satellites are in, latency is so high that it's borderline useless for anything that requires low latency (think 590ms or round trip ping times -- at best.) It is also astronomically expensive (pun intended) -- i had viasat, and it was $160 a month with a 100GB cap.
On the other hand you have cellular pr
re: Why we put satellites in space (Score:2)
Sure, we've had the ability to run copper or optical fiber or to construct microwave links for many years now. The point is, all of that hasn't really panned out to get connectivity to many challenging areas. If you live in a very hilly region, for example - you realistically can't get any telco interested in running optical fiber to everyone's door. (I used to live in such an area. Verizon refused to deploy FiOS, ever, to our area, despite being geographically right next door to areas that had the service
What's important? (Score:2)
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we've pretty much reached a wall at what we can discover about the cosmos by looking through the insane amount of dirt and water that flies around in our atmosphere. Companies like SpaceX are reducing the cost of putting heavy objects into space by 10x, movign towards 100x. Spaceborne telescopes are a far superior solution anyway. That's the future of discovering the cosmos.
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we've pretty much reached a wall at what we can discover about the cosmos by looking through the insane amount of dirt and water that flies around in our atmosphere.
Also, as interesting as astronomy and cosmology is, haven't we moved well past the point of bringing practical value to humanity's quest to survive and be better? We're so far beyond incapable of actually interacting with the objects being observed it's absurd, and any new physics we are beginning to understand are for phenomena that are ludicrously beyond our ability to tap for the advancement of mankind. I fail to see any remotely practical value in advancing these sciences until we're nearing the preci
Before Starlink constellation is completed... (Score:1)
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counterpoint: no it won't.
Don't worry, can't cancel now... (Score:2)
Don't worry, can't cancel now... We will all be dragged into this regardless of our thoughts or objections.
Many moons later when the consequences come, those who ignored our complaints will try to blend into the crowd and say things like "Nobody knew back then", or "it was the state of the world and we were just going along".
At this point it looks like regardless of the issues we are going to be going forward with this. Now our only next recourse is the part where we get proved right and get to name and sha
Misunderstandings in here (Score:2)
Solve this in software. (Score:2)
Does any astronomer use film these days? For raw sensor data: just filter out any light sources (pixel clusters) that are moving faster than a given delta. The sensor data is already run through tons of post-processing to ferret out items of interest. Just add in some pre-processing to remove items of no interest. For photon sensor based observation that is accumulated by software: this is an imminently solvable problem. The biggest concern is that any pre-processing not filter out data that is relevan
Terrestrial (Score:2)
Post processing (Score:2)
I can see a post processing software (free / OSS would be better) would be greatly helpful.
If you did amateur astrophotography, it is not actually a "single frame" like your portraits, but a very long exposure, usually in movie format. And then a software will clean up by overlaying the frames, removing noise and improving resolution.
Anyway, the same system can be enhanced with up to date starlink (and other) satellite paths, and those can be removed from the images. If you have, say thousands of RAW frames
Re:Clouds? (Score:5, Informative)
Many of the very powerful telescopes are built on mountain tops and/or areas with very little cloud cover (in days per year). And the cloud cover tends to be seasonal, so you could do larger maintenance items.
Also, astronomy is mostly done at night, when fewer birds fly. Or bats.
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How many people in the US have ever actually seen the night sky? How about in 20 years?
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Which the average person will never have access to without elite academic affiliations and a million dollar education.
Amateur astronomy is an accessible activity with millions of participants.
Data from many big 'scopes is publically available.
If you mean that few people have physical access to the 'scopes on Mauna Kea and La Palma, then you don't understand how they work. There are no eyepieces to look through. An astronomer requests the technicians point it at specific coordinates and then later downloads the data from the observatory's server. There is no need or reason to be physically present.
How many people in the US have ever actually seen the night sky?
That is because of urba
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Starlink is not visible at late night, only around dawn and twilight when they reflect sunlight.
Re:Clouds? (Score:5, Informative)
Also from the study:
They do go on to note that certain types of operations are more affected than others (for example, time-sensitive twilight observations), but it's kind of funny what the headlines omit. For example, that the one track per image applies only to twilight observations, and that ZTF is unusually vulnerable to Starlink tracks due to its mode of operation (very wide fields of view and very long exposures) - indeed, their models showed that they should have 2-3 average tracks per twilight image at full Starlink deployment, rather than just one as determined in this study (seem to be due to different observation patterns than modeling expects). But as with any platform where satellite streams will be a problem, automated streak removal is conducted in their processing pipeline, and the streaks have not proven a problem for them, at least thusfar.
They could much more accurately say, (Score:2)
They say the fraction of pixels that are lost is "not large."
They could much more accurately say it is "negligible."
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Re:Clouds? (Score:4, Informative)
Birds do not give off light. They block it, so can't generate a signal which doesn't exist. And they fly low enough that they'd briefly block the entire FOV of a telescope if they flew directly overhead, meaning even the loss of light won't really affect much.
Meteors last a second or two. You can complete a night of observation and only a few pics will have a meteor streak through it. They're predicting Starlink satellites will appear in every picture.
Planes are routed around observatories specifically to avoid interfering with their operations. Not to mention most observatories fire a high-powered laser into the sky as part of their adaptive optics [wikipedia.org] to cancel out atmospheric turbulence. You don't want planes anywhere near that laser.
Most satellites operate a higher orbits than Starlink, and in much fewer numbers. They do occasionally show up in photos, but it's a small enough deal that you can just throw away that one piece of data. Starlink operating at a lower orbit means they move faster across the sky so are harder to avoid, and they're brighter since they're closer.
I've written before that the technology used by Starlink (phased array antennas so they can maintain a signal fix on moving satellites without having to physically move, and not suffer interference even when operating at the same frequency) is compelling enough that such satellite constellations may in fact be worth the trade-off of degraded terrestrial astronomy. But pretending that the interference is on the same scale as clouds, birds, meteors, and planes, and that astronomers can just schedule around them, only demonstrates your ignorance of the issue.
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Starlink satellites only give off light around dusk and dawn when they can reflect the sun. Usually telescopes wait until deep in the night to do observations anyway, not many telescopes do twilight observation.
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Plus, SpaceX are currently demonstrating the solution to the problem. Itâ(TM)s now possible to cheaply launch satellite constellations. Put your telescopes in orbit, and get more powerful hardware thatâ(TM)s less affected by the problems of having an atmosphere above us.
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Their solution, to install shrouds, helps but does not completely fix the problem.
We are only at the very start here. Currently they have a few thousand satellites up, and have permission to got to 10,000. They are talking about a total of 40,000 eventually. And that's just Starlink, obviously other commercial and state providers want their own networks.
Some major adjustments will be needed if we end up with 100,000+ satellites in low orbits.
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He's implying that the solution is to put your telescopes in space, since Tesla shows its so easy.
I don't agree with the post, but that was his stance, not that the shroud fixes it, but everyone gets telescopes in space.
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