Starlink, how much time do we have?

[PESKYWAABBIT]

So I haven't delved much into the issue but I was curious. Does anyone have any idea of exposure times we'd realistically get when they put up all the 12,000 SpaceX Starlink satellites up in the sky before one was within a single light frame?

Cheers!

[Davey-T]

This is before Starlink so can only get worse 😥

Dave

[tooth_dr]

Genuine question - is there any point in spending several £1000s on a new mount if imaging is going to become impossible in the not too distant future?

[newbie alert]

Another 60 in orbit now

https://www.bbc.co.uk/news/science-environment-51013308

[Rob]

Just been reading the BBC piece there.. Just hope something comes out of the AAS meeting. This is going to effect our hobby in such a detrimental way. But equally (if not more importantly) The professional Astronomers & Science going forward.

Worrying indeed

[Rob]

I think also for all you imager's we are going to require some clever software that can interact with the image data to remove satellite streaks from the RAW.

[Craney]

1 hour ago, Rob said:

.... require some clever software that can interact with the image data to remove satellite streaks from the RAW.

I suppose it is an intense localised  form of a gradient and as long as you can get one decent sub free from any space junk, you should be OK and get the the offending streaks lifted out. ... fingers crossed.

Edited January 7, 2020 by Craney

[rob_r]

12,000? I thought the planned number was closer to 42,000.

[happy-kat]

I'm hoping DSS will cope if there are enough subs in the set.

[Space Hopper]

I'm sure the boffins will be able to magic up some software to mitigate the issues these pesky satellites will cause.

Have faith.

[Ouroboros]

Would it be a reasonable back of the envelope estimate to say well there are about 4 to 5 thousands satellites now and a further 40,000+ planned so the problem will be roughly 10 times what it is now. 

I reckon between maybe 1 or 2 300s frames out of ten have a satellite trail at the moment. So in future it'll be at least one or two trails per 300s frame. 

Someone pointed out on here the other day that these satellites are in low orbit so their effect will be most strongly seen near dawn and dusk. Is that right? But Musk was saying he planned to launch later satellites into higher orbits "because these would be less visible".  But that could be worse couldn't it? 

[PESKYWAABBIT]

5 hours ago, tooth_dr said:

Genuine question - is there any point in spending several £1000s on a new mount if imaging is going to become impossible in the not too distant future?

This is a similar thing I was concerned about. I'm now on the lookout for my first house and I always wanted to have my own observatory. One main requirement is some dark sky out in the sticks so I was just wondering if it's even going to be possible to get long exposure shots at low iso's in the near future. Was shooting the M81 and M82 at 1600ISO for 600s recently and didn't have a single problem with satellites for a good 4 hours. I assume this will all change soon.

[Ken82]

Sigma clip removes them ? At least it has/does for me 

[carastro]

If any one wants to sign this petition.  Not sure if it will make any difference, but something is better than nothing:

https://secure.avaaz.org/en/community_petitions/SpaceEx_Starlink_Fifty_thousand_telecom_satellites_will_make_astronomy_impossible/?aVIigpb&newuser=1

Carole

[Merlin66]

There's a lengthy article on this subject in the usS&T, March 2020 issue.

 

[wimvb]

So far I'm not too worried. As mentioned, good pixel rejection can repair the damage (in this case, PixInsight).

(Animated GIF from PixInisght forum )

But it's always better to avoid the problem. As @Ouroboros noted, the sattelites will be in lower orbit, so mostly a nuisance near dusk an dawn. Also, Musk has (kind of) listened to objections and done a Rolling Stones on the newer versions:

I see a red door Starlink and I want it painted black

[Filroden]

I feel this is too much a #firstworldproblem. We all enjoy nice internet and telephone connections so happily object to others, in less accessible places, not being able to access those same services because it might spoil our hobbies, without even quantifying how it might spoil our hobby. As Wim so clearly demonstrates, removing satellite trails is an integration 101 step. With sensor noise levels continuing to drop we can afford to take shorter and shorter subs, further reducing any possible impact on imaging. Global communication provides far more benefits to society than amateur astronomy, so I support the use of space to improve the lives of everyone even if it slightly inconveniences me. I can easily adjust my imaging strategy...large parts of the world cannot easily adjust their ability to integrate into the global communications network. 

[wimvb]

44 minutes ago, Filroden said:

As Wim so clearly demonstrates, removing satellite trails is an integration 101 step.

Just for clarification: "T'wasn't me." I took the gif from a post (cited in my reply) on the PixInsight Forum. I think that satellite trails are more of a problem for professional astronomers, where the reflections can interfere with measurements. And as telescope time is expensive, trails are more likely to ruine a research project than a pretty picture taken by an amateur who can spend many hours collecting data.

53 minutes ago, Filroden said:

With sensor noise levels continuing to drop we can afford to take shorter and shorter subs, further reducing any possible impact on imaging.

That would be the nr 1 method to avoid this problem. But be prepared to discard subs, even with kappa-sigma clipping

So @tooth_dr, go and spend that money on a new mount. As long as you have the right tools in your arsenal to deal with any artefacts in your data.

Imo, climate change and the prolonged overcast periods we've experienced the past years are a greater threat to our hobby. But to stay on topic, as I understand, Starlink isn't the only network planned in the near future. Other companies are preparing to send up their satellites. I wonder how many satellites are needed to fullfill the need, or if there is going to be an abundance of satellites when multiple companies are trying to make a buck? Who actually determines what anyone can put in space?

[carastro]

Quote

Who actually determines what anyone can put in space?

Precisely.

 

[clarkpm4242]

Hi All

Just in case you haven't seen my vid.  It is a visual pollution as well as an imaging problem...oh well.  Paul.

 

[newbie alert]

If you have the mindset to put a car into orbit, one that's not serving any purpose other than littering space with more junk, or making up stories such as no one  even thought that it could cause a issue..what really...  Anyone that's spent any amount of time outside at night has seen many satellites going across the sky.. I know at our level it be disregarded but at professional grade scopes doing scientific work it must also have a impact

I did watch a video the other day of a guy that's just started a space junk clear up company...hope he succeeds.. 

[wimvb]

2 hours ago, newbie alert said:

If you have the mindset to put a car into orbit, one that's not serving any purpose other than littering space with more junk

I believe its purpose was to balance the rocket. 😉

[ollypenrice]

Obviously this is a worry for me because I do amateur astronomy professionally. If the satellites prove fatal to astrophotography then I'll take a treble hit, losing my visiting customers, my robotic hosting operation and the value of my kit (very considerable and in effect, my 'lump sum' should I ever decide to retire.) However, there are astrophotography businesses far larger than mine. Cameras, mounts and telescopes need makers to make them and retailers to sell them so to this extent I disagree with Filroden's notion that it is just a hobby at stake. Amateur astronomy generates many livelihoods. (I'm not entirely sure that the internet brings vast social benefits either, but that's for another debate and another forum.)

Fortunately I don't think the effect will be catastrophic, though I may be wrong. If the problem is going to increase by a factor of 10 then 10 x 0=0. At the moment satellites are a non-problem. Sigma clipping gets rid of them almost entirely and the big ones, which sometimes leave a trace, may need a line removal applied to the sub in question but then they'll vanish like the rest. With CMOS chips thriving on more and shorter subs the Sigma clipping will work better than ever and I don't doubt that the software folks can up their game as well. It may be possible to write a programme actively to look for lines and then remove them.

Olly

[Magnum]

https://www.skyandtelescope.com/astronomy-news/starlink-satellites-astronomy/?fbclid=IwAR36gDC-IpwHfftlbz29_suH2O17RtKfW67Wgnc5ol0qre4wWXrSfYLonpU

This article has some video simulations showing how they will look on average with 12,000. however space x have now applied for extra 30,000 bringing total to 42,000 if approved. If Amazon and others follow with as many each, I really do think we will get to a critical point where nearly every sub could have a trail. But thats the final orbits, unfortunately for us they will be launching them at a much faster pace than the orbits take to raise and spread out, so for several years we will be dealing with them at their worst. 

Ive been reading every article I can find on the subject. one interesting youtube video was interviewing the CEO of one of the more established satellite companies that will soon be launching new geostationary satellites, and from what he said Geostationary is a better technology than LEO. much higher bandwidth and a much smaller constellation required, much less wasteful. And for Astronomers much much less impact on the sky. He actually said he thinks SpaceX may find they have taken the wrong path altogether.

Lee

Edited January 9, 2020 by Magnum

[ollypenrice]

^^^  Essential reading. Thanks, Magnum.

Olly