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Astronomers Despair as Starlink Train Ruins Observation of Nearby Galaxies
- robcohen 7y agoI understand that the astronomers are disappointed, but isn’t that because the period we are in right now is immediately before it becomes 10x cheaper to launch telescopes into space? Won’t it be so much better to observe directly from space as opposed to from the earth? Can anyone comment on this?
- rimliu 7y agoObservations are being ruined now. Those cheap space telescopes will be available when ecactly? Is there even any project in the works besides JWT? Projects like these take a lot of time.
- toomuchtodo 7y agoImprove observation data post processing. Lasers are used as artificial stars [1] to subtract atmospheric distortion, use stacking [2] to remove StarLink tracks. Those observations aren't being "ruined", they simply have some noise to remove. Long term, we should be lifting observatories (both optical and RF) into orbit, Lagrange points, or the Moon. Observing from the ground sucks comparatively, and there's a lot of space out there. [1] https://en.wikipedia.org/wiki/Laser_guide_star https://en.wikipedia.org/wiki/Laser_guide_star [2] https://www.skyandtelescope.com/astronomy-blogs/imaging-foundations-richard-wright/satellites-begone-how-to-remove-satellite-trails-from-your-astrophotography/ https://www.skyandtelescope.com/astronomy-blogs/imaging-foun... (Satellites, Begone! Remove Trails from Your Astrophotography)
- jsweojtj 7y agoThat might work for imaging, but what's your fix for spectroscopy?
- toomuchtodo 7y agoOptical, RF, or Xray?
- jsweojtj 7y agoLet's start with optical.
- peterwoerner 7y agoYes WFIRST[0] is currently in the works. JPLRMA[1] is investigating low cost mirror for space observation although they are primarily focused on the outer planets of our solar system. [0]https://wfirst.gsfc.nasa.gov/ https://wfirst.gsfc.nasa.gov/ [1]https://www.nap.edu/resource/13117/App https://www.nap.edu/resource/13117/App G 19_Enceladus-RMA.pdf
- lidHanteyk 7y agoOn one hand, yes, you're entirely right about the eventual outcome, but on the other hand, let's get there gracefully. The article describes an event akin to commercial light pollution or commercial aviation, with the similar cause of private industry charging ahead of regulation and standards. It could be that the only solution is to quickly act to regulate space more completely, but we don't have a healthy international political climate for such regulation right now. Also, in terms of quality of evidence, there is sadly a relatively strong pseudoscientific strain of thought that denies any astronomy done from space. If we stop taking high-quality photos from the surface of the Earth using relatively mundane methods, then the flat-Earthers win. Finally, what if Kessler Syndrome sets in? In that case, it would not be cheaper to launch a telescope into space, even if the telescope is destined for a relatively distant place like a Lagrange point, since it first must run a gauntlet of debris. Meanwhile, observations from the ground would certainly be twinklier and noisier but not especially more expensive.
- ncallaway 7y ago> On one hand, yes, you're entirely right about the eventual outcome, but on the other hand, let's get there gracefully. The problem with a "get there gradually" approach (at least as I understand it, and I may not have understood you correctly) is that it pretty much precludes a useful LEO constellation. A LEO constellation is not really useful unless it has a significant number of satellites. Putting up 1% of the satellites doesn't really get you 1% of the functionality of the system. There's a minimum threshold you have to hit for the system to really be viable at all. Which means at _some_ point (if we have LEO constellations at all) we're going to have to really rapidly go from very few LEO satellites to a large number.
- Miraste 7y ago> in terms of quality of evidence, there is sadly a relatively strong pseudoscientific strain of thought that denies any astronomy done from space. If we stop taking high-quality photos from the surface of the Earth using relatively mundane methods, then the flat-Earthers win. This isn't a real problem with the quality of the photos. Such people should be kept out of power and otherwise ignored. > what if Kessler Syndrome sets in? Starlink can't result in Kessler Syndrome. The time it takes orbits to decay from that altitude is measured in single-digit years.
- andyljones 7y agoNot since the advent of modern adaptive optics[1]. Ground-based telescopes now outperform space telescopes in the visible spectrum[2]. For as long as the cost per kilo to orbit is higher than the cost per kilo to the Atacama desert, ground-based astronomy is going to be superior. The other great advantage of ground-based telescopes is that _they're easy to fix and improve_. The iteration loop is that you walk into the dome and you fiddle with things. You don't need multiple years of planning to polish a mirror. There's an excellent Twitter thread on this issue here[3]. [1] https://en.wikipedia.org/wiki/Adaptive_optics https://en.wikipedia.org/wiki/Adaptive_optics [2] https://astronomynow.com/2018/07/19/adaptive-optics-tomography-provides-hubble-class-images/ https://astronomynow.com/2018/07/19/adaptive-optics-tomograp... [3] https://twitter.com/cynosurae/status/1196567663977230336 https://twitter.com/cynosurae/status/1196567663977230336
- semiotagonal 7y agoPerhaps a deal could be worked out where the satellite companies also have to launch Atacama-scale telescopes, where Musk et al have to pay for the difference in cost between Atacama and orbit.
- Rebelgecko 7y agoTelescopes are pretty big. It would take 5-10 Falcon 9 launches to put something with that mass into orbit (although in space you could probably have a lighter mechanism for orienting el/az). The telescope's mirror is also too big to physically fit into the F9's fairing. Once you get it there, you need to assemble it and keep it running. Maintenance is a real doozy— building a telescope on Earth is expensive. Building a telescope in space is even harder, since it won't be regularly serviced and you have to overengineer it. A typical space telescope still costs an order of magnitude more than a recordbreakingly expensive earth-based one.
- DennisP 7y agoYes but the point of Starlink is to fund Starship, which is a lot bigger than Falcon 9. Its fairing is 9 meters in diameter[0], large enough for all but the top six land-based telescopes.[1] Its payload is 100+ tonnes, five times larger than Falcon 9's. Starship is also a lot cheaper per kilogram of payload; at scale, as low as $20/kg. Cheap launch also makes your satellites cheaper to build, since it's less of a disaster if you have to replace them. Musk has already floated the idea of building a second-generation Starship with an 18-meter fairing.[2] [0] https://www.spacex.com/starship https://www.spacex.com/starship [1] https://en.wikipedia.org/wiki/List_of_largest_optical_reflecting_telescopes https://en.wikipedia.org/wiki/List_of_largest_optical_reflec... [2] https://www.teslarati.com/spacex-elon-musk-starship-the-next-generation/ https://www.teslarati.com/spacex-elon-musk-starship-the-next...
- daveslash 7y agoI can't comment on that specifically (telescopes in orbit, I invite others to). My two cents though are this: I frequently go on multi-day backpacking trips just to get away from it all. I can get so far out when the only human-made anything that I see are the occasional aircraft and the occasional satellite. It's a great disconnect -- I can pretend that the modern world doesn't exist. It would be a great disappointment to me if the evening/morning sky were to become so populated that there were constant reminders of the modern & interconnected world. I would be resentful of whoever ruined that for me, everyone else, and generations to come.
- sbierwagen 7y agoSucks to be you, then.
- hugs 7y agoOn these trips, do you bring an emergency radio or GPS?
- daveslash 7y agoTypically, no, but sometimes yes . It depends on how well I know the area (if at all), how far from the road, how many people are coming with, etc...I have a Yaseu FT-60, but (a) Don't have HAM license and (b) It's too heavy. I never take a GPS map, but sometimes I take an emergency GPS emergency locator (e.g. SPOT).
- Miraste 7y agoYou won't be able to see these once they are at operational orbit unless you use a telescope. And, as the article says, future launches will be nonreflective.
- daveslash 7y agoThat is encouraging. Thank you.
- cstross 7y agoHow much do you think all the sunk infrastructure costs of existing telescopes cost, and how many years did it take to build them? The bigger telescopes today have primary reflectors that are vastly bigger than the James Webb Space Telescope: for example the Large Binocular Telescope with its 8.4 metre mirrors, or the Extremely Large Telescope (currently under construction: first light due in 2024) with its 39.2 metre segmented priary. Even the segmented designs weigh hundreds of tons; these instruments are too big and heavy to put in orbit even with SpaceX's Superheavy/Starship. If the light pollution from Starlink can't be mitigated, it'll be necessary to replace dozens of hundred million dollar to billion dollar instruments which took years or decades to build, at a post potentially greater than the entire consat cluster.
- deevolution 7y agoWhat's more important? Global internet access for the rest of the world population or a few dozen telescopes? Imo internet access is going to have immediate positive impact for billions of global disconnected poor.
- cstross 7y agoI'm sure I could make better use of your home by demolishing it and erecting a homeless hostel. Isn't that more important than your prior claim to live there? (This is a m-e-t-a-p-h-o-r, not a literal proposal, but what Starlink is doing to astronomy on a global scale is pretty much equivalent. The onus should be on Starlink to (a) not do that, or (b) pay for complete relocation or replacement of the telescopes they've just wrecked. Yes, that's a lot of money. Boo hoo ...)
- shadowgovt 7y ago> The onus should be on Starlink to (a) not do that Why? Astronomers have no more claim to ownership of the sky than Starlink does.
- pintxo 7y ago
- gammarator 7y agoLaunch costs are not the dominant cost of building space telescopes, which are ~10x more expensive than equivalent ground-based systems (when they exist). Ground-based telescopes built in the 1940s are still being used for cutting-edge science today because it's simple and cheap to upgrade their instruments. That's not possible in space--when JWST runs out of propellant, it becomes just a $10B piece of space junk.
- SubiculumCode 7y agoMoon based telescopes then. Let's do it!
- ISL 7y agoPutting a person on the moon cost a significant fraction of the US GDP. The tax burden required to move Earth's level of free dark-sky accessibility to space (step outside at night, buy binoculars, a Celestron, or LSST, and just look up) would be crippling for any nation.
- SubiculumCode 7y agoBut think of the return on the investment of cool.
- kd3 7y agoWhat SpaceX should do is equip every satellite with a camera and lens specialized for astrophotography pointed away from Earth to the sky. Then give every one of them a unique ip address and interface that astronomers and anyone else can connect to and take pictures and videos. Some of them could even get equipped with bigger telescopes.
- krastanov 7y agoA ton of cheap low-quality instruments does not always equal a single expensive instrument. For optical astronomy the only currently reliable way to get higher resolution is to get larger mirrors. And we are not even mentioning the importance of a well calibrated cooled sensor.
- mturmon 7y agoThe telescope in the OP whose observations were interrupted has a 4m primary mirror. Hubble has a 2.4m primary mirror. The optical corrector lens -- just the corrector lens alone -- that is part of the camera instrument of OP has a diameter of 1m, with a mass of about 200kg. (https://www.darkenergysurvey.org/the-des-project/instrument/ https://www.darkenergysurvey.org/the-des-project/instrument/). The entire Starlink satellite mass is 227kg. I don't think SpaceX is going to be putting instruments of this class on its satellites.
- kd3 7y agoThat is not what I am suggesting either. Smaller telescopes and cameras but on every satellite which can then be combined computationally as well. Tons of possibilities. Of course, like I said, they could also equip some of them with more powerful and larger hardware. But the smaller ones would already provide lots of capabilities for very little extra cost relatively.
- mturmon 7y agoOK, but that's not addressing the problem raised in the OP. Dedicated CubeSats have largely filled the smallsat niche. I would expect the Starlink mass has been carefully optimized already. There are interesting mission concepts (telescope + star shade; NEO detection [1]) that are in the works with dedicated CubeSat constellations, but yoking them to another spacecraft bus with its own constraints doesn't sound likely to succeed. [1] https://www.aanda.org/articles/aa/full_html/2017/07/aa29809-16/aa29809-16.html https://www.aanda.org/articles/aa/full_html/2017/07/aa29809-...
- Mobius01 7y agoI worry about the precedents being created. There is little in the way of other companies or governments adding more to Earth’s orbit. Eventually there could be enough objects there that one single incident could cause a chain reaction and blanket Earth on debris making launches dangerous or impossible.
- kylek 7y agoThis has a name! https://en.wikipedia.org/wiki/Kessler_syndrome https://en.wikipedia.org/wiki/Kessler_syndrome
- tialaramex 7y agoNote that although this sort of event would make LEO unusable, which isn't good - it would _not_ actually do several things commonly portrayed in fiction alongside that. It wouldn't prevent leaving the Earth, passing through LEO after a Kessler event wouldn't be unreasonably dangerous because you're not there for long. This means you could still go to the Moon, or to Mars, if you've got any reason to do so. It wouldn't prevent us putting satellites into higher orbits, in particular the GEO communications satellites are so ludicrously much further up than LEO that to say Kessler would inhibit GEO is as if you imagined that a blocked storm drain in your street might lead to Mount Everest being covered by the rising water.
- Apocryphon 7y agoFiction may have imagined doomsday scenarios, but it has also envisioned the solution to them https://en.wikipedia.org/wiki/Planetes https://en.wikipedia.org/wiki/Planetes
- bpodgursky 7y agoAll the SpaceX satellites are in LEO, low enough that even in the absolute worst case scenario (which, FWIW, is not realistic), they will all de-orbit in a couple years.
- Uhuhreally 7y ago
- oh_sigh 7y agoI'm extremely pro-space research, but if I had to weigh the benefits of some astronomers observations being obscured sometimes versus getting hundreds of millions of people onto the internet, I think the choice is pretty clear.
- Uhuhreally 7y agothere are other ways to deliver internet
- shadowgovt 7y agothere are other ways to do astronomy
- Uhuhreally 7y agofrom Earth there's only one way: telescopes
- shadowgovt 7y agoStarlink hasn't rendered telescopes inoperative, nor will it. They still work for 99+% of viewing time, and the satellites in question are invisible on most of the radiation band telescopes can operate on. This is a tempest in a teapot complaint. Ground-based telescopes already need to account for the existence of satellites, airplanes, birds, the ISS, etc. The Starlink constellation is just increasing the number of the things; it's not changing the nature of the challenge. Or would you recommend we ban microwave ovens because they deliver noise near the radio spectra we use for Internet communication?
- ISL 7y agoBanning microwave ovens (and RF transmission in general) is precisely what is done near radio-astronomy sites (see Green Bank, the SKA, etc.)
- duaoebg 7y agoThe noise looks very predictable, should be super simple to filter out
- shadowgovt 7y agoEssentially. It's an inconvenience for individual astronomers who time-share on telescopes that sometimes a blob of Starlink passes and sometimes it doesn't. If the full constellation is launched and disbursed, everyone will be inconvenienced about equally, so the fairness issue goes away. And the degraded signal can be cleaned up with digital processing factoring in knowledge of the Starlink node positions.
- ISL 7y agoSuper simple == many people-centuries sapped from funding-strapped research. Furthermore, astronomy is just entering a paradigm where the entire sky can be imaged multiple times per night with great optical depth. Transients are going to be the next frontier, and that is precisely what these constellations will create. A few lost satellites with improperly-documented orbits can fake optical transients. Furthermore, radio astronomers have moved to the outback of Australia to get away from rare radio transients. A zoo of satellites is precisely something they don't need.
- lionheart 7y agoSo I'm confused, because according to https://caseyhandmer.wordpress.com/2019/11/02/starlink-is-a-very-big-deal/ https://caseyhandmer.wordpress.com/2019/11/02/starlink-is-a-... "Based on the Starlink website, that all satellites will be deployed below 600km. In this case, satellites may be visible during twilight but not after nightfall, greatly reducing the potential impact to astronomy." Can anybody verify this?
- deleted 7y ago[deleted]
- shadowgovt 7y agoIt's the physics of the arrangement of satellite, sun, and Earth. The satellites are only visible due to reflected sunlight, and they're flying quite low for satellites, i.e. near to Earth. The nearer an orbital object is to Earth, the larger percentage of the arc of its orbit is occluded by the Earth's shadow. Given their close proximity to Earth, they can reflect sunlight at dawn and dusk (when the sun is shining "along" the surface relative to the observer) but when an observer is in nighttime (i.e. within Earth's shadow), Earth blocks the path of light to reflect off the satellites and they won't shine. Hypothetically, they could still pass in front of distant objects and occlude them, but I'm assuming based on the way the problem is described that flooding a telescope with reflected light is more of a problem than occluding a distant object for a few moments.
- Uhuhreally 7y agothe view of the night sky is about to be destroyed by companies
- shadowgovt 7y agoNot really. The satellites will be too small to see unaided in general, and their proximity to Earth means that outside of twilight hours, they're generally invisible. (Also, "destroyed" is a matter of perspective. I think it'd look kind of cool if every twilight you could look up and see a web of satellites drifting quietly overhead ;) ).
- Uhuhreally 7y agono that would not be cool. Not at all
- shadowgovt 7y agoDifference of opinion.
- modeless 7y ago> if we’re going to go into a future where you end up losing 30 to 60 minutes, that would be a significant chunk of our observing time through the night As this comment implies, the worst case impact to astronomy is only going to be about 30 to 60 minutes lost per night right after dusk and before dawn. There will still be uninterrupted viewing time in the middle of the night because the satellites will be in Earth's shadow and not visible at all. Personally, I think the benefit of truly global broadband internet from space is worth the cost of an hour of observing time per night. Even in the worst case, ground based astronomy can still happen. "Despair" is not warranted. On a related note, I made a website to predict when the Starlink satellites will be visible for you. They look pretty cool if you can catch them, but viewing opportunities are limited because of that limited time window before they enter Earth's shadow. https://james.darpinian.com/satellites/?special=starlink-2019-11 https://james.darpinian.com/satellites/?special=starlink-201...
- pulisse 7y ago> Personally, I think the benefit of truly global broadband internet from space is worth the cost of an hour of observing time per night. SpaceX isn't the going to be the last company or nation state to put up a network of satellites like this.
- sbierwagen 7y agoDo you have any reason to believe that additional satellites would alter the geometry of the Earth so that they would be visible for longer after sunset?
- mtnGoat 7y agowould larger objects, or ones at a larger orbit be visible longer? admittedly, i dont know much about space stuffs. :)
- scrumbledober 7y agoat a higher orbit their brightness will be less, but they will be illuminated longer and visible from more of the planet. Assuming a constant average reflectivity, larger objects will be more visible.
- ilaksh 7y agoCould something like Starship carry a large mirror? Or could it ever be feasible to manufacture a large mirror on the moon, if a large enough one can't be flown?
- smabie 7y agoLaws to protect astronomy? Really? Talk about the strong needs of the few outweighing the weak-moderate needs of the many. If I was an astronomer I would be pissed, but let’s have some perspective here: vastly more people are going to be helped by this than hurt. Moreover, this sky pollution has already happened with light and eventually will become a problem with satellites. There’s just no stopping it and we should recognize that things change, sometimes for better or for worse. But mostly, better for some and worse for others.
- ksaj 7y agoLight pollution is probably a bigger problem, except on the tallest mountains, or ironically, in orbit. These astronomers seem to be obsessed with one guy, when there are way more than just his satellites up there. It makes me think it's more of a lobbying effort than a clear-sky thing.
- nickik 7y agoOnce we have that man things in space we will have the launch capacity to launch gigantic/multi satellite space overvaluation platform for gravitational and 'normal' astronomy. Astronmy will benefit from this overall. And what the alternative, for the rest of time not using this capability? I understand that they are sad, but since this doesn't even effect the majority of astronomers, I really think this is kind of a non-issue.
- ISL 7y agoIt will affect the majority of earth-based astronomers -- science these days comes from the concordance of experiments.
- colek42 7y agoStarlink is the way SpaceX is funding exploration to Mars. Please stop complaining about your minor inconvenience. Someone in the government might listen and cause needless regulation halting space exploration progress.