Astronomers Despair as Starlink Train Ruins Observation of Nearby Galaxies
forbes.com
forbes.com
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-201...
SpaceX isn't the going to be the last company or nation state to put up a network of satellites like this.
admittedly, i dont know much about space stuffs. :)
I would prefer some sort of global co-operative effort with standards and oversight so satellites are interchangeable, and supplied/deployed under a contract which shares the revenue.
the satellites will be in Earth's shadow and not visible at all
They'll still obscure any small/faint objects they transit. They aren't transparent.Can anyone comment on this?
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
[2] https://www.skyandtelescope.com/astronomy-blogs/imaging-foun... (Satellites, Begone! Remove Trails from Your Astrophotography)
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/ [1]https://www.nap.edu/resource/13117/App G 19_Enceladus-RMA.pdf
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.
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.
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.
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
[2] https://astronomynow.com/2018/07/19/adaptive-optics-tomograp...
[3] https://twitter.com/cynosurae/status/1196567663977230336
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.
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
[1] https://en.wikipedia.org/wiki/List_of_largest_optical_reflec...
[2] https://www.teslarati.com/spacex-elon-musk-starship-the-next...
With radically cheaper launches, it's becoming quite possible - not now, but somewhat soon - to actually service telescopes, with conditions superior to those under which the Hubble was serviced by Shuttle teams.
With radically cheaper launches, it's not necessary to ensure the 'scope runs 24/7 for decades without regular maintenance. It can even be replaced regularly; including by bringing it to Earth, servicing it and sending back.
Launch prices are going to drop, but so is the necessity to be extremely reliable for the space equipment, for the same two reasons: 1) it's comparatively easy to get to it for a service and 2) it's comparatively easy to just send a replacement if needed.
With space manufacturing advancements still ahead of us - we didn't really experimented with making telescopes in orbit - it's not clear if space telescopes won't outperform terran ones. Space telescopes are going to have advantages like "atmosphere doesn't block part of the spectrum" and "there is no need to make a big structure capable withstanding 1g gravity".
It's still crucially important to be able to do terran-based astronomy, and that's a problem, but there is no doubt that the astronomy revolution which started with Hubble still has major advancements to have in the near future.
All of these things are only gone be possible once launch prices are cheaper and Starlink (or something like it) is a major part of how that can happen.
If you send a technician out to the Earth-Sun L2 point (where JWST will be) so that she can throw some grease on a gear or spray WD-40 on a reaction wheel, she'll be 4 times further from Earth than any human has ever gone. Although there may be some synergy with future Lunar/Martian missions, there's a lot of work that needs to be done to figure out how to do that safely. I think L2 is the safest Lagrange point w.r.t radiation, but it's still potentially deadly.
>"there is no need to make a big structure capable withstanding 1g gravity".
While the overall structure may not need to withstand 1g continuously, you still need to design it to as much as 6 Gs of acceleration during launch (as well as significant lateral acceleration, and occasional shocks in the dozens or hundreds of gs).
Hard or soft optical adaptations to remove atmospheric distortions are far more demanding than processing required to remove low magnitude satellite trails, which is already developed and required on occasion.
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.
(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 ...)
Why? Astronomers have no more claim to ownership of the sky than Starlink does.
do you really think that? is that why companies like facebook are so interested in third-world markets? or is it because they want to elevate their ability to siphon user data and hack human emotions to become addicted for more and more money, and also that facebook wants there to be little distinction between them and and the internet in these markets?
i don't think the internet has had as big of a positive impact on society as people think it has. in no other time in history has there existed such a powerful medium for control and manipulation.
and this is ignoring the fact that most of elon's projects are born out of narcissism and hubris.
source: https://www.popularmechanics.com/space/a22240382/neptune-gro...
2) Earth-based telescopes have to withstand gravity of 1g, while in space you can have some bigger structures.
Furthermore, dark skies are a resource for all of humanity, not just astronomers.
Indeed, a lack of dark shy makes the Starlink constellation harder to see from the ground.
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.
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.
"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?
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.
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.
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.
Once we are launch 1000s of satellites we are defiantly going to have servicing satellites out there. Refueling, orbital maneuvers and so on.
Even in the worst case, decades is still not that crazy. The locations are known and can be avoid.
This is a problem, but really not any kind of gigantic issue that should stop progress.
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.
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.
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.
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?
Because I, for one, kinda enjoy being able to have the conversation we're having right now.
Global internet sounds awesome, and has undeniable benefit to humankind. Uncoordinated launches of large constellations will have some detriment to humankind. The thing I'd like to see is a clear-eyed assessment of the impacts and mitigation strategies before there are billions more in sunk costs deployed in launching these constellations. Once they're up, they're up, and large companies will lose huge if the constellations have to come back down.
Motorola's bankruptcy came from insufficient monetization of Iridium. SpaceX will be in the same boat, if they aren't already.
I'm an experimental physicist, not an astronomer. Limiting systematic uncertainty is what I do all day. When I see these constellations, what I see is a zoo of uncontrolled systematics and a shrinking opportunity to address them before they become permanent.
As someone who looks at the stars, I want generations in the future to look at the stars and have their imaginations captured by distant pinpricks of burning hydrogen, not a visual screen of our own construction. Our children's understanding of our place in the universe may depend upon it.
How much astronomy relies upon sunrise / sunset observation windows?
... but we also wouldn't be having this conversation, as I lack a land-line connection to the Internet right now.
Or could it ever be feasible to manufacture a large mirror on the moon, if a large enough one can't be flown?
(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 ;) ).
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/). The entire Starlink satellite mass is 227kg.
I don't think SpaceX is going to be putting instruments of this class on its satellites.
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-...