Understanding the Impact of Satellite Constellations On Astronomy (iau.org) 43
jrepin writes: In June 2019, the International Astronomical Union expressed concern about the negative impact that the planned mega-constellations of communication satellites may have on astronomical observations and on the pristine appearance of the night sky when observed from a dark region. Now IAU presents a summary of the current understanding of the impact of these satellite constellations, and considers the consequences of satellite constellations worrisome. They will have a negative impact on the progress of ground-based astronomy, radio, optical and infrared, and will require diverting human and financial resources from basic research to studying and implementing mitigating measures. The IAU notes that currently there are no internationally agreed rules or guidelines on the brightness of orbiting manmade objects.
Given the increasing relevancy of the topic, the IAU "will regularly present its findings at the meetings of the UN Committee for Peaceful Uses of Outer Space (COPUOS), bringing the attention of the world Government representatives to the threats posed by any new space initiative on astronomy and science in general."
Given the increasing relevancy of the topic, the IAU "will regularly present its findings at the meetings of the UN Committee for Peaceful Uses of Outer Space (COPUOS), bringing the attention of the world Government representatives to the threats posed by any new space initiative on astronomy and science in general."
Clouds (Score:1)
Wait until they find out that clouds, atmosphere phenomena, meteors, insects, birds, and airplanes exist. This IAU committee will be biased against scientific usage of spancec
Satellites have highly predictable paths. You can turn off the lens during a pass if one were to occur (such events should be extremely rare even if there were a million satellites. Second, even if you didnt know the satellite appearance timing, astronomy longer uses long exposures, instead they take hundreds of short duration exposure
Re:Clouds (Score:5, Informative)
Telescopes (both radio and visual) have a reasonable field of view (0.1-1.0x moon), plus a long exposure time (seconds to hours). There would be many encounters during each exposure or observation. A single dish radio telescope has a field of view of several moons, it would be practically impossible to 'turn off' the observation. A visual light telescope has a field of view of fractions of the moon, but the high end, liquid nitrogen cooled sensors cannot easily be 'turned off' either, without introducing vibrations that interfere with observations.
Image stacking is used to combine observations of say 800 seconds into one big exposure. Shorter exposures have poor signal to noise, longer exposures get interference from charged particles and satellite tracks. It is not as simple as you suggest. It is not practically possible to use 64000 one second exposures and expect the same detail as from 80 exposures of 800 seconds when peering deep into the universe.
In addition, the math needed to track tens of thousands of satellites, their intersection path with your field of view, requires a lot of compute power and an up to date catalog of their orbits (which change due to solar winds etc...). What you suggest is highly impractical.
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That's just plain false. Math to track satellites? Solar wind? LOL Solar wind can barely affect a giant solar sail over a period of a month, how the hell is it supposed to push a satellite off course by any measurable amount especially given that the things can be reporting their location to within centimeters constantly. Keeping track of a million objects was trivial 20 years ago. Anyway, what about airplanes, lightening flashes, and meteors? How many liquid nitrogen telescopes have been ruined by them? Al
Re:Clouds (Score:5, Informative)
You need math to calculate the position and track of a satellite relative to your location.
Solar wind can heat the upper atmosphere increasing the drag on satellites hence making them decay more. Satellites need to actively manage their positions to deal with this (and other) effects.
Lightning flashes generally are not recorded by light telescopes because the domes are closed, they do interfere with radio astronomy.
Most observatories (radio and visual) are in population sparse areas and/or high/dry mountains.
No liquid nitrogen telescope was ever ruined by a satellite, tons of images were....
And you can't ignore data for half a second when you are exposing a sensor for 800... the image is tainted. Stacking will help but S/N becomes worse.
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Seriously, people are overreaticting quite ridiculously to sats after initial launch, when they are all bunched up, half the altitude of their eventual orbit, and oriented so that they're shiny, which is not their orientation once in service.
Longer term, visual light astronomy just needs to move to space. As launch costs keep dropping, this won't be some boondoggle like the never-launching JWST, but something even groups of amateur astronomers can do.
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> Longer term, visual light astronomy just needs to move to space.
And what do amateur astronomers do? Plenty of discoveries [rankred.com] have been made by amateurs.
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Mod parent up!
Us amateur astronomers and astrophotographers already have to face lots of obstacles as it is, and we don't get a chance to set up our (usually not cheap) equipment anywhere other than close to wherever we stay (home or on vacation).
Why should we be denied our right to a decent view of the night sky, when every civilized place allows us a "NO" on neighboring buildings that would impair our "normal" view around (building codes).
Frankly, these mega-constellations' reason of existence is the US's
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And what do amateur astronomers do? Plenty of discoveries have been made by amateurs.
Like I said in the very post you're replying to, move to space. All these plans for 10s of thousands of sats depend on very cheap launch costs. Starship is supposed to be below $100k/ton. The same technology that will enable great swarms of sats will enable a group of amateur astronomers to afford to put a telescope in orbit.
If you have a 4" scope you're looking through with the Mark 1 Eyeball, it's not like the sats are going to bother you anyway. But if you're doing serious amateur astronomy, $10k is
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Seriously, people are overreaticting quite ridiculously to sats after initial launch, when they are all bunched up
Seriously they are not. People are reacting to the planned 20000% increase in the number of satellites in the sky as a result of the Starlink constellation. Quite worrisome given that satellites are already a problem.
I'm sure you didn't bother reading the link which makes no mention of anything bunched up anywhere.
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Yeah, like I said, irrational overreaction. A large percentage growth off a very small base should not concern anyone calling themselves an engineer, after all. Your average photo of the sky through a good telescope will change from 0.0 sats in the picture, to 0.0 sats in the picture. The sky is definitely falllng here.
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I guess they don't have meteors there either? Zero turbulence? Perfect skies? ..those would be far better htan anything we can build on Earth. if you destroy the space industry because of a false and unreasonable demands astronomy will suffer. People hate Earth telescopes, look at the people protesting the building of the telescope in hawaii. We need to get off this rock ASAP.
If space can be profitable we have a chance to put massive telescopes in deep craters on the Moon
Re:Clouds (Score:5, Interesting)
I guess they don't have meteors there either?
You know on a typical observation you may end up getting a satellite interfere per session (currently, not when Starlink increases the number of satellites in the sky from 2200 to 42000). In 4 years I've had a meteor interfere twice. So quite a manageable problem.
Zero turbulence?
Most telescopes are built in areas of low turbulence for this reason. Also adaptive optics.
Perfect skies?
Yep. Ever notice why there's few telescopes doing active research in Europe and Canada? Of course not. Otherwise you'd know that perfect skies is the reason telescopes are positioned where they are.
In any case all your examples are a stupid comparison and have been from the beginning. Random phenomena are quite different to a consistent and above all persistent (with 42000 of the damn things planned) interference. You can claim that this is just a bunch of whining, but all that shows if you haven't even read the linked summary much less have an understanding of what is going on.
Many satellites (Score:5, Funny)
Re:Whining is why we can't have nice things (Score:4, Insightful)
I don't consider this karma. Whining because of a voodoo fairy god may get upset is quite different to setting back the progress of science.
Re: Whining is why we can't have nice things (Score:2)
And destroying the space industry what does that do for science?
Telescopes on the moon can be much more powerful and better than anything we have on Earth. How would it happen if your vendetta against space technology succeeds?
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The space industry is motoring along fine without satellite megaconstellations.
There are currently ~800 astronomical observatories on Earth, not counting the many amateurs that contribute at a professional level. It'll be a long time before all of them can afford to launch telescopes into orbit.
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Of course relations with indigenous populations is never just about one thing. If, say, the Chinese took over the running of the United States at gunpoint, you'd find a lot of fault with how they ran things, even when what they were doing was reasonable.
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If they designed the facilities so that they are literally shitting on the graves of the ancestors, and moving the toilets to the left by 10m would fix it, then yeah, build the toilets 10m to the left.
Which is exactly what was done from the beginning, under a permitting system that limits astronomy to one bowl on the side of an enormous mountain (largest in the world, because of its shield-volcano gentle slope) that is nowhere near the Native venerated sites. This arrangement is fine with eceryone except a small group of Natives who conder the entire mountain their own.
Trill (Score:2)
may have on astronomical observations and on the pristine appearance of the night sky when observed from a dark region
They pointed a satellite at a blank area of the sky for a year and found it crammed with more galaxies, raising the total estimate to one trillion galaxies.
I wonder if the occasional shiny satellite messes that up.
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10 days, not a year.
This particular observation (Hubble Deep Field) was made by Hubble, which orbits above LEO satellites. IIRC the Starlink sats are in elliptical orbits that put them above Hubble for part of the time.
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Zero real astronomers (Score:3)
No way any real astronomer would be anti-satellite. We are dealing with a minority, wouldnâ(TM)t be surprised if the same anti-science people pushing anti-GMO, anti-vaccine, anti-telescope in hawaii, etc. are fueling this. We literally have people that never cared a damn about astronomy suddenly being huge advocates of the field. No doubt a temporary faux-alliance to block space technology. Mark my words, once they succeed they will turn on Astronomy as well as they already have. Watch how they successfully blocked the telescope in Hawaii from being built. It will be a matter of time before some South American tribe claims the VLT telescope is violating some ancient sacred septic tank network. Guaranteed the anti-satellite movement is just another front of the broader anti-science movement. Some foolish astronomers are playing right into their hands. Let me ask you this, who will be left when they come for your telescopes?
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No real astronomer would be anti-satellite, as long as the numbers are within reason.
Since you are asking, I have a MsC in Astronomy, worked with Westerbork and VLA data, sat on a mountain in Chili for three weeks peering at the skies. Currently own three telescopes (14", 3" and 2"), many digital cameras and 2 CCDs.
And I am completely against these huge constellations being put into orbit without any consideration for the impact on science. At least they should take measures to minimize reflection and inter
Re:Zero real astronomers (Score:5, Informative)
That's a load of nonsense. Astronomers have valid concerns and are addressing them in a civilized manner. First by working with the satellite operator, second by gearing up to set standards for how reflective satellites can be. Nothing about this is anti-science.
Re:Zero real astronomers (Score:5, Insightful)
By the same logic, real drivers who are stuck in traffic jams wouldn't complain because that's *anti-car*.
Note what you're claiming here: the premier international organization of professional astronomers has been co-opted by a cabal of anti-vaxxers, and somehow none of those "real astronomers" noticed.
Conspiracy theories flourish because on some level believing that a sinister cabal is working against you is more comforting than the reality that you can't always have everything you want. The heart manufactures reasons to believe or disbelieve what it will, and those reasons feel more persuasive than logic, evidence or common sense.
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These satellites don't serve a scientific purpose. Their purpose is merely to make money. If they get in the way of scientific work, it's not at all paradoxical for scientists to be opposed to them.
I'll tell you where to put 'em (Score:1)
We Seem To Have Lost Sight (Score:2)
...of the really valuable service these satellites are intended to provide, reliable, affordable internet service over every square inch of the planet.
That is a big deal. If astronomers are going to have to write software to track these satellites, and throw a blanket over the telescope opening for the relatively short duration of the passing of the satellite, then the extra work is going to be "worth it." Having an ideal observational environment at the expense of such great advantage to all people of t
Scopes in space !? (Score:1)
At first, telescopes in space would be in orbit somewhere, not on the far side of the moon. There is seismic activity there, landing them with the needed precision would be complicated, there would not be enough light to power solar panels and there is no advantage compared to a steady orbit.
But anyway ground based scopes have advantages over space based ones. They are order of magnitudes bigger than space based ones. They are also critically less expensive. You can service them. Often if needed. You can al
Existing regulations (Score:2)
The radio spectrum used by satellites is already refulated (by the FCC), limiting the frequencies a satellite can transmit on. This is done to avoid interference with other radio systems, including radio telescopes.
Let me repeat that: satellite operators already have to accommodate one class of astronomers. It's not such a great leap to extend that to other parts of the spectrum when they turn out to cause problems.
Musk Can Fix It (Score:2)
bigger concern: International Astronomical Union (Score:2)
The fact that most of the world runs with SI just because it makes *scientists* have easier jobs shows you how much the tail is wagging the dog. I can mentally estimate a foot far better than a meter because I know about how big my foot is.
Auditors and scientists should NOT be allowed to run the world. Keep them away from the table.
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Not sure if this is intended to be funny or not. I was going to moderate it Funny but goofed.
Time for telescopes on the Moon (Score:2)