Thank you Xilman

Forums Imaging Project idea Thank you Xilman

Jim Verner

Thanks Paul,

I see the error of my ways! Yes I should have used steradians.

Also, I want to point out that although it may seem I’m biased aginst Starlink et al, I’m not. With thirity plus years in the broadcast engineering and audio visual events sectors I’ve used more than my fair share of satellite links and I’ve no doubt (love them or loathe them) I’ll probably end up using one or more of the new systems. My concern is that there seems to be a lack of real hard (non biased, non emotional) facts out there on which any of us can make a real judgement. On one side there are those going…. ‘Nope, nothing to see here, won’t impact us at all…’ and then on the other side…. ‘It’s the end of civilisation as we know it, we’ll never see the stars again!’ Now I suspect that the big observatories will come up with a software fix in their image processing and likewise those who use stacking will delete all the frames that have been impacted before processing, so there’s work-arounds for both. But what about the guy in between (like me) who’s a bit old school and just likes to look up at the stars, take some long(ish) exposures from time to time, maybe use some blink comparison looking for DSO’s and have no desire to spend lots of time processing images. It’s a big enough struggle to get time for the hobby as it is, so to have exposures ‘photobombed’ by satellites continuously would be soul destroying.

Anyway, here’s the revised maths.

So, that would be 360 / (2 x pi) = 57.3 (there abouts) and then (4 x pi) x 57.3^ = 41253 square degrees as you quite rightly point out.

That would then give us a concentration of  46,270 satellites divided across 41,270 square degrees 

  46,270 / 41,253 = 1.12 satellites per one square degree

So, if the moon covers an area of 0.2 square degrees (if memory serves me correctly) that equates roughly to one satellite for each area of the sky equal to five times the area of the moon based on the lower number of satellites or 1.38 satellites in the same area if using the higher number of 57,120.

Is my maths correct?? That seems like an awfully high figure to me.

I will and do freely admit to being purely a stargazer at best so at best my calculations are nothing more than a laymans scribbles on the back of an envelope at best. I do fear though that  the whole [subject, debate, discussion or whatever the current comments around the globe may be regarded as] is simply becoming lots and lots of peoples opinions and hard scientific data is proving very difficult to come by. In the meantime Starlink et al will continue to launch more and more satellites into orbit without anyone being able to conclusively prove if they will or will not be a problem. So, like David Swan (op) I’m curious to see if there is a study anywhere and if not it would be great to see someone pick it up as a project and run a proper in-depth impact study.

Thanks again to Xilman for pointing out the flaw in my initial calculations.

It’s all way above my head….. in more ways than one.  🙂