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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

#71

Post by joshvm »

genewitch wrote: post #67
testing22321 wrote: post #48

Earlier quoted context omitted.

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…

Tens of seconds is about right. It's something like 500/f(mm) in seconds, but you get a feel for what will blur and what won't. Here's an example I shot with a Nikkor 50mm f/1.4 @ 20s: https://www.instagram.com/p/C-mU6iIp0re/?igsh=cm16bWx1cGp3OG...

Re: An image of the Australian desert illuminates satellite pollution

#72

Post by WalterBright »

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.

Consider a shaped charge. It seems wild to me that you can direct an explosion with various shapes of the explosive. Perhaps a similar idea can apply to the blackbody radiation - get it to radiate mostly away from the satellite.

Also, the black part will be pointed at the Earth, not the Sun.

Re: An image of the Australian desert illuminates satellite pollution

#74

Post by youngtaff »

WalterBright wrote: post #32
WalterBright wrote: post #20

Just paint the satellites black?

It should also be possible to de-orbit obsolete satellites faster if they can at end-of-life deploy a "sail" that will cause more drag.

And then we have to consider what’s the effect of all those vapourised metals on the atmosphere

Re: An image of the Australian desert illuminates satellite pollution

#78

Post by teamonkey »

rafram wrote: post #46
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.

No, you need to take a long exposure. Multiple exposures may improve the quality but isn’t necessary at all.

If the camera is stationary you must stack multiple short exposures to avoid star trails. You can only take long exposures with an equatorial mount.

Re: An image of the Australian desert illuminates satellite pollution

#79

Post by teamonkey »

chii wrote: post #75
madmask wrote: post #27

I wonder what uncontacted tribes think about starlink

well, if you could observe these things with the naked eye, they might imagine it's similar to a passing meteor.

You absolutely can see them with the naked eye. Very easy to spot on any given clear night if you know what to look for, especially when they’re moving in a cluster. They don’t look like meteors, far too slow.

Re: An image of the Australian desert illuminates satellite pollution

#80

Post by blitzar »

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.

Poor, remote rural people need influencers to tell them which lambo to buy too.
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