
SpaceX satellites could blight the night sky, warn astronomers - Cbasedlifeform
https://www.theguardian.com/technology/2019/may/28/spacex-satellites-could-blight-the-night-sky-warn-astronomers
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AngryData
Wouldn't be a problem if we didn't let telecomms fuck us in the ass so badly
that we need this.

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autocorr
Obviously high-bandwidth satellite internet is important. Speaking from a
place in the USA where we only have one option for pretty crappy DSL internet
(at $60 a month), I would probably even be among the first to try and get it!
Before you criticize scientists as having tunnel vision for attempting to
stymie global world progress, consider that astronomers are not and have never
been in a position to have any regulatory power on this issue. At most they
can inform the public of the side effects.

There was a similar situation when a Russian private company sent up a
satellite that would deploy reflectors to purposefully make it one of the
brightest objects in the night sky[1]. I image some astronomers breathed a
sigh of relief when the reflectors didn't properly deploy.

In radio astronomy, there are a few small protected bands to keep some
portions of the spectrum quiet for scientific purposes. There is no such
"spectrum allocation" for optical astronomy. Like chopping down the rain
forest or putting plastic in the ocean, we may improve our quality of life
through external costs. Governmental regulation permits us to partially
control for these externalities. Perhaps if we find ourselves in a big mess
like with CFC's and destroying the ozone layer, we will have a public call-to-
action to create regulations.

So, what's the rub? Ground based telescopes are vastly cheaper than space-
based alternatives for optical and radio astronomy. The difference in cost is
often more than two orders of magnitude. If ground based telescopes become
less efficient or less productive, there will simply be fewer scientific
discoveries made within a flat budget. If the public is required to increase
the budgets of NASA, NSF, ESO, and ESA to maintain their desired level of
scientific output, then that in itself is an external cost that SpaceX and
other companies are passing on.

[1] [http://spaceflight101.com/soyuz-kanopus-v-
ik/mayak/](http://spaceflight101.com/soyuz-kanopus-v-ik/mayak/)

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tapvt
As a landowner in a dark sky zone, I can’t decide if the trade-off is worth
it.

It’d be nice to have Internet way out there. But at the cost of my (and
everyone else’s) pure night sky?

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LargoLasskhyfv
One more reason to utilize the far side of the moon for some seriuos
astronomy! Am I rite?

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floatingatoll
Has anyone yet built an AR simulator app of what SpaceX informs us will be
their satellites’ visibility with correctly-aimed panels at various times of
day, dusk, and night?

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perilunar
This is such an incredibly short-sighted view from astronomers. The same tech
that is going to enable SpaceX to launch thousands of satellites is exactly
what will enable (and fund) the expansion of humans into space — which will be
more of a boon to astronomy in the long term than any number of large ground-
based telescopes.

I'm perfectly happy to permanently screw over ground-based astronomy if that's
what it take to get us into space.

Just build the damn telescopes in space. And stop thinking single-mirror
scopes like Hubble — you could build huge multiple-segment mirrors in space —
much bigger than anything on earth.

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errantspark
Someone ought to do a simulation of what this would look like with the full
constellation. I love stargazing, I take days long trips to go to dark sites
just so I can enjoy the sky. I imagine it would be quite beautiful to see that
the implied lattice around the earth as sun glints off the solar panels.

I'm personally so excited to see these, I think it will be a breathtaking,
tangible emblem of one of the first planet-scale systems that humans have
built.

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sdinsn
> His estimates suggest that once the first 1,584 satellites are launched, for
> which the trajectories have already been made public, there will be about 15
> satellites clearly visible above the horizon for three to four hours after
> sunset and before sunrise.

Oh no, 15 tiny lights in the sky. Not really a blight.

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akvadrako
Actually, this is a good point.

I care about light pollution a lot and think most people are missing what I
had when I grew up (Canadian/American border in the 90's). I wish cities had
strict codes and <1% of the waste light they do now.

But dark skies are not dark at all - there are about 10000 visible stars. A
few moving dots is not going to ruin the experience.

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nonnontrivial
Wondering if these satellites follow a fixed path. If so, and there are few
enough of them, the nextgen land-based optical telescopes will just have to
factor this into scheduling.

Has SpaceX said anything about the paths they will follow? Can they change
mid-deployment?

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aeternus
They all have Xenon thrusters and can move, however will do so only when
needed to dodge other satellites or debris. Changing their orbit significantly
is prohibitively expensive.

You can see the general pattern in a really cool webgl animation on the main
site: [https://www.starlink.com/](https://www.starlink.com/)

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maxander
From a minute of googling, there’s roughly 5k satellites in orbit right now.
Most of those are in a slightly higher orbit than Starlink’s (LEO) so they’re
incrementally farther away, but would be in a better position to catch
sunlight in the night sky.

And yet I, probably like everyone else who isn’t an astronomy enthusiast,
haven’t ever looked at a light in the sky and known it was a satellite.
They’re subtle, not dominating the night sky by any means, at least insofar as
an untrained modern human can tell. Starlink would up the number of satellites
by ~2x, perhaps, but would that be enough to change the basic equation?

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dingaling
> at least insofar as an untrained modern human can tell

Perhaps, but that's irrelevant to this discussion which was initiated by
competent experts in their field. Not like protests against 5G which are based
on dodgy YouTube videos.

Starlink will have a significant impact on the global night sky based solely
on the approval of one agency of one country of 8% of the World's population.
Even if you as a layman don't perceive it to be a problem in your daily life,
doesn't that just seem... wrong? If North Korea had taken such a step there
would be sanctions.

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SmokeGS
Billboards from LEO. I'm not a fan but it could monetize key tech for space
travel.

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Robotbeat
As a defender of space travel and Starlink: Nobody in their right mind wants
that. Public reaction would rightly be swift and negative. Starlink provides a
useful, widely available service and the fact you can see them is a side
effect (they're not very bright operationally, so it's not really a negative).
But a billboard is effectively legal graffiti.

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thecrumb
Not too worried about it. They have a shelf life and I imagine their design
will improve over time.

I'd rather see some regulations against all the lights in the Walmart/shopping
mall/grocery store parking lots which have completely ruined the night sky in
my area.

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batbomb
The shelf life isn't the problem. The problem is quantity in the sky (this
will continuously be relaunched) and how bright they are. This will ruin many
long exposures for many existing telescopes, but you can do some amount of
image subtraction if you do many short exposures. That's might be a problem
for some instruments depending on their readout electronics.

It's also a global problem.

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aeternus
The video in the article is not representative. Solar sails were not in the
final position and the satellites were not in their final (higher) orbit. It
was also taken during the short time-window that the sun was still
illuminating the satellites.

Regardless, we should be moving our telescopes to space. Much less
interference of all kinds.

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batbomb
The amount of light will still be appreciable and will affect many kinds of
observatories around the world, even at magnitudes less brightness.

You also can't slew a telescope in space like you can on ground, it would be
extremely cost prohibitive in terms of fuel.

"moving telescopes to space" is the equivalent of "let them eat cake" comment
in this funding environment. It sounds like a wonderful proposition until you
realize how many observatories we have on the ground and their utilization and
how expensive it would be to replicate half that utilization. It's already not
easy getting time on a telescope, if everybody had to be crammed on 15 space
observatories costing $1B/each, there would be no observational time for grad
students or post docs let alone funding for research. You also kill follow up
observations on temporal events.

Of course, maybe the government could reach an agreement with SpaceX to send
up the observatories for free and send some money the way of the astronomers
for seriously messing up the sky, but there's no reason to expect SpaceX to be
a good citizen of the night sky.

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perilunar
>You also can't slew a telescope in space like you can on ground, it would be
extremely cost prohibitive in terms of fuel.

You can use reaction wheels instead for zero fuel use.

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batbomb
not quickly

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vikramkr
Is it worth protecting ground based astronomy here though? Obviously the
science is immensely important, but so is the internet, I dont buy this idea
about the lack of consensus being an issue. Certainly the scientists should
have had their say, and perhaps this should have been put up for a more public
debate before the project was initiated, but I don't think that the go ahead
to the project should be contingent on consensus from the scientific
community. It should be contingent on approval from a regulatory body that is
appointed/controlled in some democratic way and reflects the will of the
population, and if the benefits to society outweigh the risks, then it should
get the go ahead regardless of consensus by astronomers.

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mdorazio
Possibly unpopular opinion: no, I don't think it's worth protecting ground-
based astronomy. I could be wrong, but the majority of the important visual/IR
astronomical observations from the last decade seem have come from space-based
instruments, not ground-based ones. We need to put more instruments in orbit,
not worry about fundamentally limited ones on the ground.

Additionally, this seems to me like an overall positive effect for the public
at large. Being able to see satellites zooming across the sky is pretty cool,
provides educational opportunities beyond what normal stargazing offers, and
reminds people that there's something to aspire to (and look forward to)
beyond what's on the ground.

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givinguflac
While obviously we're making more advanced measurements with space-based
instruments, the value of the night sky for the average human cannot be
overblown. Many people don't know what they're missing, having never lived
outside of broad scale light pollution. While I don't think we necessarily
need to worry about all ground-based telescopes, I do think that the average
person being able to look at the sky and see the stars is something we should
never give up on.

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jasonhansel
I agree with this sentiment 100%. Looking up at the sky and seeing a massive
chains of satellites would be a lot like finding piles of trash along a hiking
trail.

