Stargazing The Curse of Elon Musk: Redirect Satellites to Sun or His Backyard?

[davenn]

TL;DR Summary

this guy should be locked up !!

Seriously, this guy has destroyed astronomy for amateur and professional alike
His actions are criminal and this is just the start
just one recent example ...

Maybe he should redirect his satellites in a path that avoids blocking celestial objects that astronomers are interested in?
May I suggest a path directly INTO the sun? If not, how about directly into Elon's back yard? Either would suit me just fine...

 

[DrStupid]

His actions are criminal

It is even worse. His actions are not criminal due to a lack of corresponding rules. As long as the satellites are duly registered they are perfectly legal. There is nothing that could stop him or others from spamming the sky.

 

[davenn]

It is even worse. His actions are not criminal due to a lack of corresponding rules. As long as the satellites are duly registered they are perfectly legal. There is nothing that could stop him or others from spamming the sky.

uh huh, maybe I should qualify the comment ... criminal to everyone outside the govt's that allow this sort of thing

 

[DrStupid]

the govt's that allow this sort of thing

They do not allow it. They just forgot to forbid it. Nobody considered this situation when the international space law has been established. But instead of a corresponding update there is currently reather a tendency to cancel international treaties.

 

[berkeman]

Are there practical things that can make satellites like that more stealthy? Paint them with non-optically-reflective black paint?

 

[davenn]

Are there practical things that can make satellites like that more stealthy?

In general, it's difficult as more often than not, the sat's surfaces are covered in solar panels for battery charging,
and they are very reflective, I haven't seen a photo of one of these actual satellites before launch

 

[Ibix]

Or if the orbital data is available, can you program your camera to filter them out?

 

[andrew s 1905]

Take multiple images and stack using median combine and that should remove them.
Regards Andrew

 

[SchroedingersLion]

Post in on Twitter, maybe you get a response

 

[Jando]

Classical conflict of interests: some people want to earn money, others want to do science. The money people usually win.

 

[davenn]

Or if the orbital data is available, can you program your camera to filter them out?

there's too many of them and 100's more coming. trails like that cannot be filtered out

 

[davenn]

Take multiple images and stack using median combine and that should remove them.
Regards Andrew

Image stacking is the norm anyway, doesn't help, too many of these bl$$dy things

 

[davenn]

The money people usually win.

Sad but true

This image from the International Astronomical Union
.

 

[256bits]

Isn't that typical of humans to soil their environment and think nothing of it, as long as it doesn't affect themselves.
Light pollution just gets getting more and more "disgusting." They built a new bridge here and what do they do - this is the federal gov't by the way who tries to pass themselves on as being environmental mindful - they light it up with those colored LED lights for show, and the public blabbers say what a sight - no regard for the little kids that will grow up and never see a clear sky in their growing up years and fantasize about the universe.

Well, technological progress, and the push for immediate gratification, does indeed have its downside.

 

[gleem]

Do these satellites present any problems for the new Thirty Meter Telescope in Hawaii? If not how are they mitigating the presence of the satellites?

 

[websterling]

Do these satellites present any problems for the new Thirty Meter Telescope in Hawaii? If not how are they mitigating the presence of the satellites?

They might mitigate the problem with satellites in the Hawaiian sky by building the telescope in the Canary Islands!

 

[russ_watters]

Are there practical things that can make satellites like that more stealthy? Paint them with non-optically-reflective black paint?

Thermal management is critical for satellites, so probably not.

 

[russ_watters]

Image stacking is the norm anyway, doesn't help, too many of these bl$$dy things

While I haven't experienced the Starlink specific issue yet, previously I would just reject subs that had this issue. But it should be possible to subtract the streaks from each sub before stacking. A dark streak has a whole lot less impact on the stack than a bright one.

 

[davenn]

Do these satellites present any problems for the new Thirty Meter Telescope in Hawaii? If not how are they mitigating the presence of the satellites?

Every telescope anywhere on Earth with a latitude of ~ + - 65 deg going by the images I have seen
showing their satellite orbital coverage

They might mitigate the problem with satellites in the Hawaiian sky by building the telescope in the Canary Islands!

HUH ??! I have to assume that was a joke because if it wasn't, then you don't understand the problem !

 

[berkeman]

Paging @mfb -- was this part of the planning for these new arrays of communication satellites?

 

[websterling]

HUH ??! I have to assume that was a joke because if it wasn't, then you don't understand the problem !

It was supposed to be a joke, hence the exclamation point! The joke being that any problem with anything in the Hawaiian sky (which was specifically mentioned) would be mitigated if the telescope were built in the Canary Islands.

I thought it was funny. And, FYI, I do understand the problem.

 

[gleem]

Every telescope anywhere on Earth with a latitude of ~ + - 65 deg going by the images I have seen
showing their satellite orbital coverage

Then as far as they are concerned there is no (significant) issue with the satellites.

 

[davenn]

Then as far as they are concerned there is no (significant) issue with the satellites.

HUH ??
who are they ?
please explain your response

 

[gleem]

Then as far as they are concerned there is no (significant) issue with the satellites.

Professional astronomers since they have been building new terrestrial telescopes since the first satellite was launched.

 

[mfb]

The Starlink satellites are launched to a height of ~300 km and raise their orbit to 550 km using ion thrusters. To do so they fly in a low drag configuration, which makes the solar panels very visible around sunset/sunrise. After they reach their operational altitude the current satellites re-orient their solar panels and dim to magnitude 5-6, future satellites might become even dimmer (they are testing a new coating right now - you can't make it black, but they change the directions the light is reflected/scattered to). With 5-6 they are only visible in places with a very dark sky, if the new coating works well they will become completely invisible to the naked eye. Telescopes will still spot them, of course, just like they spot the thousands of other satellites, that is unavoidable.

Only a few batches of satellites are raising their orbit at the same time, and while they do so they have predicable orbits (so astronomers can plan ahead) and they enter the shadow of Earth quite soon due to their low orbits (they are not visible for most of the night). It's not a big deal for professional observations. They would prefer absolutely no satellites apart from orbital telescopes, obviously, but that's not realistic.
If you absolutely need to take an image of a region in the sky at the time a train of satellites will fly through you can still take many images and remove the satellites in software.

I haven't seen a photo of one of these actual satellites before launch

Here is one. With annotations here.

Professional astronomers since they have been building new terrestrial telescopes since the first satellite was launched.

It is not without impact, but the impact is not as large as some people claim.

Classical conflict of interests: some people want to earn money, others want to do science. The money people usually win.

Some people want internet access. About 3 billion of them do not have internet access at the moment, but such a satellite constellation can provide internet for nearly everyone - they only need a user terminal. I really hope they win. Internet access for everyone is so much more important than a few affected pictures of selected night sky objects.

 

[TeethWhitener]

From this CNN article:
https://www.cnn.com/2020/01/29/tech/spacex-starlink-satellite-internet-launch-scn/index.html

"Astronomers have also raised concerns about the multitudes of Starlink satellites disrupting their view of the night sky. SpaceX says it's working with the science community on ways to address those issues."

 

[DEvens]

The appropriate requirement is for Elon Musk to provide free transport of astronomers, all the telescopes, a large amount of support equipment and material, and family members, to a base on the far side of the moon.

That's where you want to be to do astronomy anyway.
- No atmosphere to ruin exposures. No weather. No clouds. Nothing to block the parts of the spectrum that don't get through even clear air.
- Light pollution from cities far less important because no atmosphere to reflect it. Even when there are cities.
- Put up a sun shade and very little change in temperature. So your telescope is not going to "krink" as the daily temperature cycles.
- No wildlife to fly into the telescopes.
- Two week exposures with very little effort.
- And it is never "moon bright." Or even "Earth bright" on the far side.

Probably not a bad place for the gravity wave detector folk also.

 

[mfb]

Here is a system that blocks exposure for places where satellites are - all of them, not just Starlink. It uses tracking information and then just stops recording in the region directly around the satellite. Overall loss of exposure time is tiny.

 

[anorlunda]

Here is a system that blocks exposure for places where satellites are - all of them, not just Starlink. It uses tracking information and then just stops recording in the region directly around the satellite. Overall loss of exposure time is tiny.

Thanks @mfb that's an obvious solution that is not obvious until you think about it. So astronomers will be forced to use a system like that, but when they do the problem mostly goes away.

I read that companies other than SpaceX have similar plans for orbiting nets of satellites; on the order of 45K satellites planned so far.

It is hard to dispute that Internet access for all 7 billion people on the planet is a high priority human welfare issue. Maybe all of them will become PF members and post to this thread

 

[OCR]

It is hard to dispute that Internet access for all 7 billion people on the planet is a high priority human welfare Facebook issue.

OK, I admit it. . . I obviously messed with your quote. . . .

Lol. . . I believe I made it "more truthful". . . .

Maybe all of them will become PF members and post to this thread

Maybe all of them will become PF members, sometime, after they hold a Facebook

account ?

Carry on. . . . .

.

 

[strangerep]

This image from the International Astronomical Union
.
View attachment 256070

Seriously? You haven't figured out that Elon Musk is a leader of the vanguard for an imminent alien colonization of the Earth? Putting up hundreds of satellites is to reduce our ability to spot the approaching armada and maybe jam any nuclear missiles we might send their way.

(Btw, it's easy to tell that EM is an alien, just from that lame face mask he always wears.)

 

[Keith_McClary]

The appropriate requirement is for Elon Musk to provide free transport of astronomers, all the telescopes, a large amount of support equipment and material, and family members, to a base on the far side of the moon.

I'm sure he would be happy to promise that.

 

[mfb]

Astronomers are not forced to use a system, but it does improve the quality of some observations. It's quite an obvious approach I think.

I read that companies other than SpaceX have similar plans for orbiting nets of satellites; on the order of 45K satellites planned so far.

~12000 for Starlink (SpaceX), 650-2500 for OneWeb, ~3000 for Project Kuiper (Amazon). Telesat (Canada) and China are planning constellations with a few hundred satellites. SpaceX is considering more satellites but that is not a fixed plan yet.

 

[Gary Feierbach]

It seems to me reflected photons are wasted photons as far as energy generation is concerned. Why should solar panels be reflective? Alternatively, use the NASA black to trap photons and generate thermal phonons to operate solid-state thermoelectric generators (Alphabet Energy).

 

[mfb]

An ideal solar panel wouldn't reflect anything but an ideal solar panel doesn't exist.

Alternatively, use the NASA black to trap photons and generate thermal phonons to operate solid-state thermoelectric generators (Alphabet Energy).

Too inefficient, especially without a cooling source.

 

[DrStupid]

Too inefficient, especially without a cooling source.

Assuming the same size for collector and radiator I calculated a theoretical maximum of 0.85 % for the efficiency (according to Carnot's theorem). Is that possible? That would be really inefficient.

 

[russ_watters]

It seems to me reflected photons are wasted photons as far as energy generation is concerned. Why should solar panels be reflective?

An ideal solar panel wouldn't reflect anything but an ideal solar panel doesn't exist.

Most solar panels are black and reflect very little; the issue is the satellites themselves, which are mirrored for thermal management. If you made the satellites themselves black (or covered with solar panels), one side would be really hot and the other really cold.

Now, even at low reflectivity (a few percent), you'd get a lot of light from a flat solar panel, but it would be a rare, localized flare, not a continuous, widespread, even brightness reflection people are seeing.

 

[mfb]

The brightness during orbit raising comes mainly from the solar panel. It is very large compared to the main satellite. The brightness in the operational orbit comes from the satellite body.

 

[russ_watters]

The brightness during orbit raising comes mainly from the solar panel. It is very large compared to the main satellite.

But why would that cause it to reflect light toward Earth? Isn't it pointed directly at the sun?

 

[anorlunda]

Is this just a variant of Iridium Flares?

@russ_watters , you're an amateur astronomer, haven't you seen satellite flares before.
On my boat in the keys, the whole harbor watched for ISS flyovers and Iridium Flares, use the heavensabove website as a guide. https://en.wikipedia.org/wiki/Satellite_flare

Iridium flares[edit]
Double flare - Iridium 6 and its replacement, #51, both flare in a 21-second exposure.
If a first-generation Iridium satellite is still controlled, its flares can be predicted.[1] The Iridium communication satellites have three polished door-sized antennas, 120° apart and at 40° angles with the main bus. The forward antenna faces the direction the satellite is traveling. Occasionally, an antenna reflects sunlight directly down at Earth, creating a predictable and quickly moving illuminated spot on the surface below of about 10 km (6.2 mi) diameter. To an observer this looks like a bright flash, or flare in the sky, with a duration of a few seconds.

Ranging up to −9.5 magnitude, some of the flares are so bright that they can be seen in the daytime. This flashing has caused some annoyance to astronomers, as the flares occasionally disturb observations.[2]

The article also says:

Flares may also occur from solar panels, but they are not as bright (up to −3.5 magnitude).

 

[mfb]

But why would that cause it to reflect light toward Earth? Isn't it pointed directly at the sun?

Not while it is raising the orbit, where it flies in a configuration that reduces drag. See my previous post.

 

[trurle]

From this CNN article:
https://www.cnn.com/2020/01/29/tech/spacex-starlink-satellite-internet-launch-scn/index.html

"Astronomers have also raised concerns about the multitudes of Starlink satellites disrupting their view of the night sky. SpaceX says it's working with the science community on ways to address those issues."

The mfb have already mentioned dark coating, and the SpaceX have deployed a prototype of low-reflectance satellite. So called "Darksat", or Starlink-1130. Specifically for astronomers. The measured g-band brightness reduction is 55%.
https://arxiv.org/pdf/2003.07251.pdf

 

[mfb]

7.57 at 976 km is 7.0 at 550 km, below the visibility for the naked eye even under perfect viewing conditions (typically assumed to be 6 to 6.5). This doesn't include geometry corrections, but overall the conclusion is that Darksat-style satellites completely disappear to the naked eye. Good for a prototype. Musk said that future satellites should be even darker, making them easier to remove from pictures for astronomers.

I noted that Starlink-4 (the latest launch) seems to be harder to spot already, but I don't have precise numbers.

The next launch is planned for March 18, 12:21 UTC (in ~25 hours).

 

[lstellaus]

Even painted black the satellite would block a distant star. Trying to average multiple snaps would interfere with precision measurements needed to determine distance, mass, etc. It's about time to do something about these billionaires that think they do whatever they want.

 

[Helena Wells]

Summary:: this guy should be locked up !

Seriously, this guy has destroyed astronomy for amateur and professional alike
His actions are criminal and this is just the start
just one recent example ...

View attachment 256047Maybe he should redirect his satellites in a path that avoids blocking celestial objects that astronomers are interested in?
May I suggest a path directly INTO the sun? If not, how about directly into Elon's back yard? Either would suit me just fine...

All of Musk's satellites are solutions provided by Dr. Sheldon Cooper(when he was a kid) so if there is anyone to blame it is him.

 

[mfb]

Half a year and 6 launches later and astronomy still exists. Satellites now come with a sunshade that prevents the Sun from falling onto the most reflective surfaces. This is mainly relevant for satellites in their final orbit to avoid saturating astronomical sensors. In addition they change the orientation of the orbit-raising satellites when they are close to the terminator, making them much darker - this change largely affects the naked-eye visibility early on.

Even painted black the satellite would block a distant star.

That probability is utterly negligible, and even then it's for less than a millisecond.

Trying to average multiple snaps would interfere with precision measurements needed to determine distance, mass, etc.

Quite the opposite, you need to do that anyway.

It's about time to do something about these billionaires that think they do whatever they want.

Like regulating satellite launches? Great, because that's already being done.

 

[Helena Wells]

Half a year and 6 launches later and astronomy still exists. Satellites now come with a sunshade that prevents the Sun from falling onto the most reflective surfaces. This is mainly relevant for satellites in their final orbit to avoid saturating astronomical sensors. In addition they change the orientation of the orbit-raising satellites when they are close to the terminator, making them much darker - this change largely affects the naked-eye visibility early on.That probability is utterly negligible, and even then it's for less than a millisecond.Quite the opposite, you need to do that anyway.Like regulating satellite launches? Great, because that's already being done.

Maybe we should create stelites with big gravity(high density) so we could see the stars behind them due to gravitational lensing.

 

[Ibix]

Maybe we should create stelites with big gravity(high density) so we could see the stars behind them due to gravitational lensing.

You might want to run some numbers on that. To misquote Chief Brody, you're going to need a bigger rocket.

 

[Helena Wells]

You might want to run some numbers on that. To misquote Chief Brody, you're going to need a bigger rocket.

We would need a denser rocket not bigger. Probably made of lead and some of its oxides and we could see behind the satellite.

Lead has a density 1k times less than a neutron star so the effects are not neglible.

 

[etotheipi]

We would need a denser rocket not bigger. Probably made of lead and some of its oxides and we could see behind the satellite.

But even if you manage to fulfil this requirement, there's still the small issue of getting it off the ground