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An image of the Australian desert illuminates satellite pollution

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Re: An image of the Australian desert illuminates satellite pollution

#61

Post by goku12 »

changoplatanero wrote: post #14
ThrowawayTestr wrote: post #6

[flagged]

And pollution down here on earth is way higher priority than light pollution in long exposure photographs of the stars

People have different priorities. Dismissing the needs of the scientific community based on meaningless comparisons for the financial benefit of a few megacorps isn't really a good argument. There are much less disruptive ways to provide good quality internet access for folks even in the most remote places. Considering the US especially, can you honestly say that the telecom companies did everything they could (or even a reasonable bit) to improve the situation, using all the subsidies and grants they took from the government in the name of improving the said connectivity?

Re: An image of the Australian desert illuminates satellite pollution

#62

Post by goku12 »

kibwen wrote: post #3
kofianon wrote: post #2

A startup idea: launch satellites to capture clean night sky photos, with tiered subscription model of course.

Startup idea: launch anti-satellite satellites to de-orbit other satellites littering your airspace.

There's no concept of airspace in space. You have very few avenues to keep a sat restricted to a geographic region. Orbits like geostationary and molniya exist - but they come with their own limitations for many applications.

Re: An image of the Australian desert illuminates satellite pollution

#63

Post by disconcision »

ibizaman wrote: post #11
nntwozz wrote: post #10

You know those airplanes with a banner at the beach? I can imagine a constellation of satellites writing ads (live) in space using mirrors and other nifty tech. Unless regulation stops it.

That’s so true. I can see it too. The technology to make that must be super fun to work on but please I hope this will never happen. Can you imagine turning the whole sky as a giant pixelated screen to constantly show us ads? That’s as dystopian as it gets. Add to that the probable less than secure software to run it and hackers trying to show stuff up there. That’s something out of a Douglas Adams book. xD

earliest sci-fi antecedent i know off: https://en.wikipedia.org/wiki/The_Man_Who_Sold_the_Moon

Re: An image of the Australian desert illuminates satellite pollution

#64

Post by saddat »

macinjosh wrote: post #26

It is so polluted you need professional camera gear and processing of hundreds of photos together in order to show it. Get real. Internet access for poor, remote rural areas across the global is more important than convenient timelapse photography.

Starling et al are about profit, ignoring their impact to humanity

Re: An image of the Australian desert illuminates satellite pollution

#65

Post by Panzer04 »

saddat wrote: post #64
macinjosh wrote: post #26

It is so polluted you need professional camera gear and processing of hundreds of photos together in order to show it. Get real. Internet access for poor, remote rural areas across the global is more important than convenient timelapse photography.

Starling et al are about profit, ignoring their impact to humanity

And they profit because people need the valuable service they provide.

I doubt astronomy is as important as providing good internet access to millions of people in low-service areas around the globe.

Re: An image of the Australian desert illuminates satellite pollution

#67

Post by genewitch »

testing22321 wrote: post #48
threeseed wrote: post #29

Earlier quoted context omitted.

These photos are taken in pitch-black darkness. You need to take a lot of exposures in order to get the data necessary to even see anything.

This is a single 10sec exposure in the Aussie outback on old consumer gear ( Sony a7iii ) https://www.instagram.com/p/CersLuLBfCz You don’t need multiples, and you don’t need an overly long exposure.

It sounds like you know what you're talking about until one realizes the earth is spinning. Wide field photos can be shot up to thirty seconds depending on the back and lens.

Anything more zoomy than 50mm uncropped you're getting streaks in Best course of action is to take a video and let a stacking program deal with it, especially if you use a real telescope.

Also the Sony a7r have like "150,000 ISO " and iirc cost like $3500 with a kit lens. That's a bit above consumer, but I may have mixed up models.

Re: An image of the Australian desert illuminates satellite pollution

#68

Post by genewitch »

defrost wrote: post #47
xoa wrote: post #28

Earlier quoted context omitted.

Can't tell if you're joking or not, but SpaceX has indeed been collaborating with astronomical observatories to reduce the apparent magnitude (brightness) to ground for Starlink satellites. It's not as if the potential issues weren't apparent and reported on pretty early on, ie, [0] in summer 2020 before the network entered beta. It's not perfect and the period during orbit raising before the satellites enter operati…

It's not just optical pollution, the same satellites visible in the article photo over the Pinnacles are leaking radio spectrum noise into the ostensibly "Radio Quiet Zone" of the nearby Murchison that's home to cosmic microwave sensors and one regional part of the developing global SKA radio telescope platform.

This would be real simple to prove, Starlink Satelites downlink on the same band as Satelite TV so you can use the receiver from a dish that downconverts it to something a cheap dongle can handle and put that all inside a grounded, metal box in the bed of a diesel and just record spectrum.

I was under the impression that actual space business people had ways of not leaking RF when flying over.

Re: An image of the Australian desert illuminates satellite pollution

#69

Post by defrost »

genewitch wrote: post #68
defrost wrote: post #47

Earlier quoted context omitted.

It's not just optical pollution, the same satellites visible in the article photo over the Pinnacles are leaking radio spectrum noise into the ostensibly "Radio Quiet Zone" of the nearby Murchison that's home to cosmic microwave sensors and one regional part of the developing global SKA radio telescope platform.

This would be real simple to prove, Starlink Satelites downlink on the same band as Satelite TV so you can use the receiver from a dish that downconverts it to something a cheap dongle can handle and put that all inside a grounded, metal box in the bed of a diesel and just record spectrum. I was under the impression that actual space business people had ways of not leaking RF when flying over.

It's been proven by several teams already, eg:

  In new research accepted for publication in Astronomy and Astrophysics Letters, we discovered Starlink satellites are also “leaking” radio signals that interfere with radio astronomy. Even in a “radio quiet zone” in outback Western Australia, we found the satellite emissions were far brighter than any natural source in the sky.
from: https://theconversation.com/starlink-satellites-are-leaking-...

referencing: Detection of intended and unintended emissions from Starlink satellites in the SKA-Low frequency range, at the SKA-Low site, with an SKA-Low station analog (Sep. 2023)

https://arxiv.org/abs/2309.15672

It's an ongoing issue in that Starlink v1.0 leaked and as I recall promises were made that the next generation of satellites would leak less and turn off when over radio quiet zones .. that second gen group have (IIRC) more noise and continuing transmitting over RQZ's.

Re: An image of the Australian desert illuminates satellite pollution

#70

Post by qingcharles »

goku12 wrote: post #56
WalterBright wrote: post #51

Earlier quoted context omitted.

Put the black surface an inch away from the satellite, supported by standoffs. That'll keep the heat away from the satellite. Also, the black surface only needs to be on the Earth facing side.

It isn't that simple, is it? Even if you place the black surface on a spacer (adding mass, might I add), the black surface itself is going to radiate heat back onto the satellite via blackbody radiation. This is always going to create a worse thermal situation unless you can somehow radiate away as much heat as you could with reflections. To see what I mean, check out JWST's thermal shield.

To complicate it further I thought that some of the military sats had rotating black panels to shield them from ground visibility?
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