SpaceX satellites could blight the night sky, warn astronomers
35 replies, posted
https://www.theguardian.com/technology/2019/may/28/spacex-satellites-could-blight-the-night-sky-warn-astronomers
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.
This means that in winter there would be several hours of the night during which no satellites would be visible. But in summer the satellites would be visible all night.
Once all the 12,000 satellites are launched (assuming they are placed in similar orbits) 70 to 100 would be visible at night during the summer months, Bassa calculates. “These mega constellations are going to add drastically to the number of satellites that are visible at any time,” he said.
Néstor Espinoza, an astrophysicist at the Max Planck Institute for Astronomy, in Heidelberg, said: “It’s basically a private company staining our sky for everyone. It’s interesting that there’s no consensus about it. No one asked us.”
SpaceX is just one of nine companies known to be working on global space internet, meaning the eventual number of satellites could be far in excess of this.
I think there's an interesting discussion that can be had around this topic. SpaceX aren't the only actors that are planning on sending up thousands and thousands of satellites. Once all of them are up they will severely hamper groundbas observational astronomy for everyone on this planet.
Elon has responded by asking the Starlink team to find ways to darken the satellites.
I think I'll have to withhold judgement until the satellites are in their proper locations and albedo reduction measures are taken on future satellites. If we can reduce the visibility of future ones, current ones won't be up there forever, so they'll eventually be replaced.
We'll have to see. But I think people are over reacting. Especially when plenty of the night sky is already ruined by light pollution and planes.
I mean, I might not be looking at the night sky all the time, but I have never seen a Satellite with my own eyes, I don't know if having an additional 12,000 will change that.
I'm supposedly going to have a pass real soon so I'll take a peek and see how big of a deal it is with my own eyes. Will report back
To our naked eye it will not be a big issue. But I can see it being a huge issue for observatories. And of course a huge annoyance to hobby astronomers. I'd rather see some type of communication between private companies with scientific institutions or relevant international organisations.
Time will tell how much this will mess with astronomy.
A lot of them are at quite low altitudes, so you're likely to be able to see them. There are a lot of satellites up there but 12,000 is a huge number. I think Starlink is a good idea overall though. I love astronomy so it could pose a problem, but Elon Musk replied to somebody on Twitter to say they're looking at albedo reduction for future ones.
And since there are 9 other companies planning the same we're going to see it potentially reach upwards 20,000 + satellites.
Update: I couldn't see anything, but it was semi cloudy and I got a lot of trees. Will keep trying
I always found that image to be quite deceptive though, since obviously each dot is massive compared to the debris being highlighted, it makes it seem like each piece of debris is fucking miles across.
You're not an astronomer
You can see the space station and satellites moving in the sky if it is dark enough. Plenty of duck hunting trips where we are in the middle of the lake at 4am and you can track shit with the bare eye.
There's no monitor in existence that could accurately represent the relative scale of those objects. Even if there was, the pixels would be so small that you'd not be able to see them.
At any rate, Kessler Syndrome is a similar idea to how nuclear weapons work - a critical mass can create a self-sustaining chain reaction.
I'd point that the satellites will only be visible during twilight (which isn't a good time for astronomical observations anyways).
https://i.redd.it/t5qx6zw66w031.jpg
Might be a good idea for SpaceX to maybe coat the earth facing sides of the satellites with something to reduce their reflectiveness though.
Also the satellites are designed to be deorbited at the end of their life. If they fail before they can be deorbited, they orbit low enough that their orbit will naturally decay within a few years.
Twilight is the only time one can observe Mercury and to a certain extent Venus, so it's still quite significant.
Kessler syndrome isn't relevant, the satellites are not contributing to it because they can be tracked and controlled and when positioned correctly, will naturally decay into the atmosphere as their service dates expire.
It is relevant because other objects that collide could potentially damage trackable satellites too. There are also some extremely small pieces of debris that we can't react to fast enough. 12,000 is not enough satellites to be a cause for concern yet, but it's adding to the risks, especially since more companies are planning to do it.
Didn't realize that. That said, unless the Starlink sat directly transits in front of the planet, its not likely to be a problem.
>Nonetheless, it is always a challenging object to observe because it never
ventures far from the Sun – at most 28.3°. This means it must always
be observed in twilight, either at dusk or dawn. Additionally, because it is
always close to the horizon at these times, it must always be observed through
thick layers of the atmosphere where seeing conditions are poor.
Seems to imply that space telescopes and/or probes would be a better fit for the observation of these planets.
Space telescopes and probes are better for observation of all planets and really anything in space. The only reason land telescopes are still used so much is because they're far cheaper to build and can often have better optics due to fewer constraints on them.
I don't think Starlink would really cause an issue viewing Mercury/Venus for people who knew what they were looking for, but if an amateur without much experience was looking for Venus in the morning and saw bright lights on the horizon, they might get a bit confused about what they're supposed to be looking at. It's not a huge deal though.
This isn't about you, this is about all of us, especially the astronomers who will have to deal with ten times as many satellites ruining their data. Not to mention radio astronomers, who will now have a blanket of satellites screaming in the frequencies they're trying to observe. The fact that Elon Musk doesn't seem to know that satellites are often visible (to the naked eye, not just using binoculars or telescopes) well after sunset and before sunrise is disconcerting to say the least.
There are plenty of ways to expand internet access worldwide which don't involve increasing the number of satellites in LEO by an order of magnitude. And before you say "but high speed internet for developing countries!" - did anyone even check with them if this is what they wanted? This is Silicon Valley SOP at its finest: invent a problem that doesn't really exist, come up with an outrageous solution that sounds great on the surface but has a whole bunch of issues when you look deeper, and pretend that you're a visionary genius who's saved the world.
I don't think many people know how frequently satellites pass above us no matter the time of day. Them not being visible to the naked eye doesn't meant the observatories won't pick it up.
I wish it was a less reputable company or a country like China sending these up. You can bet there'd be much consideration about this.
I think a few of these issues weren't really apparent until these satellites were launched. Albedo is something you have to measure firsthand.
In any case it's not a permanent problem, if this network ever gets shut down; at 540km, the satellites will have their orbit decay within 5 years. For the ~300km V-band satellites, their orbits decay in just under a month.
Hell, if you're paying attention you can easily see a few satellites on a good night. And keep in mind this is with roughly 1,400 satellites in low-Earth orbit. Musk wants to put twelve thousand in LEO. And this is one company; if others follow suit we could easily have tens of thousands of these things in the night sky.
The impact of these satellites on astronomy may end up being minimal, or at least strategies to mitigate them can be worked out. But the fact that not a single astronomer was consulted before Musk started launching dozens of them into space is very, very worrying. A single private company being able to alter the night sky for the entire human population is something we should be questioning, not celebrating.
Astronomers, or at least radio astronomers, had to be contacted as by FCC law before the satellite could be approved. The satellite does avoid protected radio astronomy frequencies, but only tenative talks were achieved between SpaceX and radio astronomers meaning that other considerations may not have been taken into account.
I'm imagining a post-apocalyptic world where what's left of humanity sees satellites dropping out of the sky one by one. Could make for a good story, i just hope it won't be reality.
Read this article for some background on how, even with all these regulations and recommendations in place, radio astronomy is still suffering from an increase in radio spectrum pollution. Protected bands are only a small portion of the spectrum that radio telescopes observe at, and even then some of these get ignored because they're only recommendations. The FCC recently okayed 5G networks even though it could fuck up meteorological observations: do you really trust them to put the interests of radio astronomers anywhere but rock bottom on their list of priorities?
This is what I meant by 'other considerations'.
Their statement is out.
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