Satellites, space debris may have already brightened night skies 10% globally – and it's going to get worse Constellations of satellites and chunks of space debris orbiting Earth and reflecting sunlight may have lightened our night skies by more than 10 per cent, scientists say. We're also told the light pollution is increasing. “We expected the sky brightness increase would be marginal, if any, but our first theoretical estimates …
Can we please have the links open in new tabs as they used to?
Example of what I don't want with some mark-up deleted to stop linking.
href="https://t.co/fgplrWtgha">pic.twitter.com/fgplrWtgha
Example of what I do want:
target="_blank" href="https://twitter.com/olesovhcom/status/1373280258171019271">announcement
No, I mean links in the articles -- the ones that go in article text that link out to stuff on other websites. Those we try to make open in new tabs. If you click on the tweet, it should open in a new tab or play in the current tab -- it just works for us.
Ultimately, if you reeeeallly want a link to open in a new tab, remember to press Control (or whatever your browser uses) when clicking the link to force it to a new tab.
C.
You're in the business of accurate reporting of facts. If you mean only "links in the articles" then say so. It's quite different to "Every link on the page...". How much of the rest of this article, or any other you write, has such sloppy reporting?
Why? You can choose to open in a new tab if you want to. You can even make that default. Why should a link to a different page on the same site open a new tab by default? That just leads to ten tabs including eight zombies which I'll have to close later. The browsers give you an easy way to ask for that if you want it.
If it makes it any easier for you, the us government would be glad to help!
Let us help you home with the mighty light reflected off one of the National Reconnaissance Office's older keyhole satellites. It's like a personal spotlight from the heavens!
Note, due to orbital mechanics you may need to complete your trip in only a couple of minutes (or radians), and only once every 4 days or so. We're always watching, Just not always watching you!
Brought to in partnership with NSA, don't worry they're always listening!
There were several 'Lunar' societies in pre-streetlight Britain. They would meet on nights of the full Moon so that they could find their way home afterwards more easily.
https://en.wikipedia.org/wiki/Lunar_Society_of_Birmingham
"The Lunar Society of Birmingham was a British dinner club and informal learned society of prominent figures in the Midlands Enlightenment, including industrialists, natural philosophers and intellectuals, who met regularly between 1765 and 1813 in Birmingham. At first called the Lunar Circle, "Lunar Society" became the formal name by 1775. The name arose because the society would meet during the full moon, as the extra light made the journey home easier and safer in the absence of street lighting."
"Constellations of satellites and chunks of space debris orbiting Earth and reflecting sunlight may have lightened our night skies by more than 10 per cent, scientists say.***"
Because that claim at face value makes it sound like that's 10% brighter all night, every night. That would be making the night sky 10% than a full moon, which I assure you it is not. It is most likely not even 10% brighter than a new moon with a couple of planets in the sky.
If in fact they mean 10% brighter than the darkest parts of the sky on the darkest nights when the moon and planets are below the horizon they should be ethically compelled to say so when talking to the press. If they mean something else they should say so.
and which other scientists? Did I miss one?
***One person said this, and maybe some others wrote a paper about it with this person, but were not naming them if they did, and we aren't listing pesky details like units, baseline measurements, or more than one axis on our graphs at a time.
From the article:
“We expected the sky brightness increase would be marginal, if any, but our first theoretical estimates have proved extremely surprising and thus encouraged us to report our results promptly," said Miroslav Kocifaj, a senior researcher at the Slovak Academy of Sciences and lead author of a study into the light pollution, published today in the Monthly Notices of the Royal Astronomical Society.
From the (linked in article) paper's abstract:
According to our preliminary estimates, the zenith luminance of this additional light pollution source may have already reached ∼20 μcd m−2, which amounts to an approximately 10 percent increase over the brightness of the night sky determined by natural sources of light. This is the critical limit adopted in 1979 by the International Astronomical Union for the light pollution level not to be exceeded at the sites of astronomical observatories.
So there is a definition of what they mean (zenith luminance, apparently). And no, it is not "brighter than the full moon". Journalists also do not like qualifying statements, which would make your statement clearer (and above all, scientific correct), so you need to factor that in when reading about some new research. Every. Single. Time. It is not the scientists' fault (mostly), but what they say gets contracted and redacted and mangled and finally published. Source: own experience and that of former colleagues.
Of course it is easier to just attack the scientists (and stay anonymous in the comments). Well done.
I used to listen to various BBC stations during the day, from Today on Radio 4 in the morning, to Radio 1 and Newsbeat (is it still on Radio 1) and Radio 2, and sometimes 6 Music
It was very interesting to hear an initial interview, which then made it into sound bites and headlines on the other stations (and sometimes even Radio 4 again).
During the day, less and less information was provided, and the headline was altered and the sound bites made shorter, so that by the end of the day, I would be shouting at the radio (while I was driving) that the story had morphed into something that it wasn't. And this was the BBC!
Non-specialist journalists are really the worst people around to be reporting on anything vaguely scientific, and even the science editors sometimes just chase catchy headlines.
Whatever happened to researching your article's contents.
"Whatever it was – likely the rocket's second stage"
Not "whatever" or "likely", that's what it was.
"SpaceX is attempting to fix the glaring brightness of its satellites. Last year, it launched one that sported a visor to deflect sunlight."
Every batch launched for months has been visored.
Perhaps a dumb question, but why not just paint Starlink satellites matt black? Seems easier cheaper than devising, making and integrating a visor into each one.
I admit to being poorly informed on this. Would they get too hot?
Yes I know black paint can still be reflective, but there are some carbon-based blends with extremely low reflectivity.
I found this paper, might be of interest to you: "Review of black surfaces for space-borne infrared systems"
https://wp.optics.arizona.edu/optomech/wp-content/uploads/sites/53/2016/10/persky-1999.pdf
The paper mentions several uses for painting certain parts of satellites black, the most common being to protect optical sensors on space telescopes from stray light reflected into it, or as a calibration surface for telescope instruments to measure from. It does say the article is intended to be a broad overview of black surfaces in space, but specifically painting a whole sat black to reduce the light reflected back to earth was not mentioned.
So it does talk a lot about out-gassing of the paint/coating, and durability of the micro-structures on the coating's surface in space, if the black relies on surface texture to reduce reflectivity. Doesn't talk about how much heat gets absorbed.
However, one bit I found VERY interesting is the sections about temperature do mention great "emissive" performance. At one point they imply a black coating on anti-sun-facing side can help cooling, to the point where a failure-prone liquid radiator system could be designed out of a satellite. See page 2, paragraphs 2 & 3.
Also see page 7.
This tells me that it could be entirely possible for Starlink sats. I believe only the bottom (earth-facing) side of the sats reflect light that we see post-dusk/pre-dawn, so even if a black coating produces quicker heating, the time windows where heating is occurring should be minimal, and then once the black side of the sat is in earth's shadow (or on the sun-side but facing anti-sun), it should provide extra cooling.
All in all, with a slightly different thermal design, I think they could definitely do it if they wanted to. Source: whale biologist.
The extreme light pollution of the southern UK (Coventry for me), is probably pretty standard for much of humanity now. If I get up about 3 in the morning, they have turned off(down?) some of the street lights so the number of stars visible increases from perhaps a dozen to perhaps 50. I do not think satellites are going to make much difference to this.
Before anyone can criticise, Starlink, or anyone else, they need to fix the, far worse, ground based, light pollution.
In the UK the CPRE does an annual check of how many stars people can see in the constellation Orion:
https://www.cpre.org.uk/what-we-care-about/nature-and-landscapes/dark-skies/star-count-2021/
Last night was 'clear' for Reading, UK, but I could only count 7 (seven) stars in Orion, which indicates severe light pollution. The formerly pink light pollution has changed, probably due to the replacement of low pressure sodium streetlights to white LED ones.
The clearest skies I have ever seen were around midnight from the Himalaya, but I was too cold to enjoy them!
>>The clearest skies I have ever seen... too cold.
Northern Minnesota for me ( I'm sure it does not get as cold at what Eclectic Man saw but still... )
Now I have to go pretty far north to really see much these days,
Around Minneapolis I can only see a handful regardless of time of night.
On a related note, I have often wondered if there is a practical way to add sensors to the types of lighting systems used by cities? Where n individual light would be able to quickly/efficiently fire up and power down as a person/object approaches and recedes?
" I have often wondered if there is a practical way to add sensors to the types of lighting systems used by cities? "
Yes and it's being done.
More importantly, lighting that DOESN'T fire upwards is needed, as is legislation about light trespass
The UK is particularly bad for this. Streetlighting "falls through the cracks" on nuisance lighting laws to the point that scotland had to add an extra sentence to their laws to ensure that councils could be forced to comply ("any stationary installation" - something missing in England/Wales/NI) with the environment act 1990
Or for non-astronomers who live in or visit some place that's not completely swamped by ground-based light pollution. Here at the Mountain Fastness the Milky Way is normally visible at night, and when seeing is good (well after dusk, the Moon isn't visible in the sky, no cloud cover) the night sky is quite a sight. The same is true for some of the more-remote locations we've vacationed at in Michigan.
I don't need Musk's space crap cluttering that up so he can make another fortune selling fast transatlantic links to HFT firms.
As the article notes, this research is more regarding astronomy. Observatories try to locate themselves away from ground-based sources of light pollution, but they can't do anything about spaced-based sources causing an increase in background light everywhere.
There's also the question of scope. You say "they" need to fix the far worse ground-based pollution, but who exactly is "they"? Ground-based light pollution is an entirely local matter, not even at the country level. Your light pollution in Coventry is irrelevant to someone in the Lake District, let alone someone in America. But space-based pollution can be caused by anyone anywhere in the world, and affects everyone everywhere. So they're really two entirely separate problems, and it's an entirely different "they" who needs to be involved in addressing the issues.
...but who exactly is "they"?...
They are the people complaining. A useful life rule is if you want something done, make it happen. For example, if you think things should be done about climate change, get your energy use down before telling everyone else to.
If astronomers are unhappy about light pollution affecting astronomy, they need to persuade their local councils to change to streetlights that light the ground and not the sky as well before they complain about stuff in orbit.
Well that's the thing about light... even when the streetlights point downward, light is reflected from all surfaces to a varying degree, in arbitrary directions. A lot of that reflection goes up, still create light pollution.
The only way to prevent that is to not use street lighting, which seems unlikely to happen.
> If astronomers are unhappy about light pollution affecting astronomy, they need to persuade their local councils to change to streetlights that light the ground and not the sky as well before they complain about stuff in orbit.
I have - at a very, very reasonable cost to you - a brand-new streetlight of my own invention that lights the ground but ensures that none of that light is reflected up into the sky to cause light pollution. It's also extremely economical on both running and maintenance costs as it doesn't need bulbs of any sort.
> If astronomers are unhappy about light pollution affecting astronomy, they need to persuade their local councils to change to streetlights that light the ground and not the sky as well before they complain about stuff in orbit.
You've missed the point so much, it flew so far over your head, it's probably still in orbit.
Observatories ALREADY ARE located far away enough from cities & bright towns that they don't affect their measurements by that much.
The light pollution they're concerned about comes from space.
EVEN IF you created some fictional law which required every town, city & village across the entire planet to turn off every light after dusk, this light pollution from space would still exist. Your point is moot.
"If astronomers are unhappy about light pollution affecting astronomy, they need to persuade their local councils to change to streetlights that light the ground and not the sky as well before they complain about stuff in orbit."
You've completely missed the point. Astronomers generally don't care about the lighting their local council has control over, because they built their observatory 3000 miles away at the top of a mountain in the middle of a desert specifically to avoid that sort of thing being a problem. They complain about light from things like satellites, because that's now a problem that actually affects them.
In addition, use of the word "before" is really quite bizarre. Most people are capable of contemplating more than one idea at a time. It's entirely possible for someone to complain to their local council about local lighting issues, and also complain to Elon Musk about Starlink. They might even be able to send a whole two emails to different people in the same day!
Sadly, you're far from alone in this. Every time anyone dares talk about the problems caused by one particular issue, people jump out the woodwork to whine about them not talking about every other problem facing the world today first. If you weren't complaining about light pollution in Coventry, you'd be criticising them for talking about astronomy at all when they could be trying to save the whales or feed starving children in Yemen. Fortunately not everyone is like you, so we're actually able to take a stab at fixing some problems without being frozen into total paralysis by the fact that other problems continue to exist at the same time.
When the council put in the new street lights around here a few years ago, the night sky became much more visible, especially from the loft window above the street lights. I doubt the council seriously considered light pollution as a reason for choosing the lights they did. The primary reason for the new lights was the old ones needed replacing and the new ones are cheaper to run and there is far less "waste" light because they are much more directional, ie downwards.
stealth satellites... hmmm...
if they keep solar panels pointed directly at the sun, the back sides could be reflective to dissipate heat. This could minimize the number of reflective surfaces in which the sun would reflect onto the earth. So you'd potentially solve the solar heating problem AND reflectivity.
(no doubt the cost would be higher as well, moving solar panels and the necessary gyros and thrusters and fuel needed to remain stable)
Low-altitude orbits limit the time the satellite is in the sun and the ground-based observer isn't. You will see this as satellites track across the sky and then "blink-out" as they pass into earth's shadow.
I'm surprised that astronomers complain about LEO satellites as they probably don't do much observing while LEO satellites are visible. There will still be a challenge where a satellite directly obscures a target, but this will only be for a very short duration and I'd have thought that planes (that actively emit light - strobes, anti-collision and navigation lights) and clouds are more of a problem.
Is this a case of not-in-my-(celestial)-back-yard?
Yes they are only an issue for a very small set of astronomers which look for variable objects near sunrise/sunset. This doesn't affect most 'deep-space' astronomy.
Some of this is that the complaining groups aren't the 8m+ telescopes on remote mountain tops, it is local amateur astronomy groups. What complaints there are from professional astronomers is partly "slippery slope" and partly "noblesse oblige" light pollution is something that should be campaigned against.
Radio astronomers are really screwed - but they don't have such pretty pictures, Andrea Ghez aside, so nobody cares.
Yes they are only an issue for a very small set of astronomers which look for variable objects near sunrise/sunset. This doesn't affect most 'deep-space' astronomy.
Then, if THIS is the case, WHY are their claims of illuminating the night sky by 10% ?
There seems to be a contradiction here...
"Here’s an extreme example of just how bright these objects can be. Last week, it appears one of SpaceX’s Falcon 9 rockets, which was launched on March 4 to put a bunch of Starlink birds into orbit, reentered our atmosphere over the west of the United States...."
That's not an extreme example. That's tosh. There are a lot more leteors than there are Musk orbitals.
Agreed, that is not an example at all, a re-entering object is a transient like a meteor, rather than the permanent orbiting light the main story is about.
I do agree with the main story though, being a sometimes amateur astronomer, sky glow and satellite tracks are a pain for photography.
If we put enough crap up there it may offset the global warming caused by man-made greenhouse gas release. Of course then we'll all shift to non-gg energy sources and freeze to death due to the drop in greenhouse gases.. <LOL>
As a species we do seem to like crapping in our own backyard. "Humans, oh they suffocated in their own crap, not that anyone misses the filthy vermin litterbugs" :-(
Long walk in the central European countryside, far away from the next city. Returned to the car in the dark. Sat there, reflecting on how the Romans shared this same sky. Suddenly, a string of bright pearls, three, maybe four satellites in a row, passes above. And again, not much later. Probably Musk's doing. And I thought: Who gives these people the right to change our night sky forever? And what happens when China, Russia, India and the EU launch their own thousands of internet satellites? As most people have pretty much lost touch with nature, and most people making political decisions live in cities, I don't see a big lobby for a natural sky there.
it's the same arguments regarding street lights. San Diego metro area is near Mt. Palomar Observatory. Over the years the observatory's night sky requirements have influenced the color and placement of street lights in the metro area. It's a compromise between dark and dangerous night time streets vs an unusable observatory.
Orange and yellow lights that direct their light downwards seem to work pretty well. But comments earlier about LED lights, and considering the high level of blue [which is VERY bad for your eyes, I might add] and their effect on light pollution relates to this.
OK we paint the satellites orange. Helps to find them if they "splash down" too I bet... [ok they'd burn up but still, the color of an orange life vest might be filterable by telescopes]
> dark and dangerous night time streets
Has it not been proved that criminals find darks streets as intimidating as 'law abiding citizens" do?
If you're lurking in the dark, waiting for a victim, how do you know that that barely perceptible blur coming 'round the corner isn't another predator looking for you?
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