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“Beyond the limit”: Satellites and mirrors in space pose threat to the night sky

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Re: “Beyond the limit”: Satellites and mirrors in space pose threat to the night sky

#321

Post by privong »

bazodedo wrote: post #247
privong wrote: post #228

Earlier quoted context omitted.

There's at least two issues with this line of thinking: 1. many astronomical observations are long integrations (many minutes of open shutter) and you often cannot read out the pixels during the exposure. So you can't selectively ignore pixels on a "by moment" basis. And with enough satellites, enough pixels could be affected to render an entire image effectively unusable 2. It seems you're thinking only about optica…

How about putting our astronomy experiments into space as well? There'd be no light / em pollution there, as well as no atmospheric interference etc. and, 24/7 free power courtesy of our sun. Id expect orbital observatories to be superior to ground based ones, thinking of Webb, Hubble. I suppose the only downside is cost. So, the actual problem, is how to tax the shared resource that is our LEO. Aside from that, wed…

> How about putting our astronomy experiments into space as well? There'd be no light / em pollution there, as well as no atmospheric interference etc.

One would need to put the telescopes into fairly high orbits in order to avoid the interference. I think that even images made with the Hubble space telescope have sometimes seen the impact of satellite constellations.

Re: “Beyond the limit”: Satellites and mirrors in space pose threat to the night sky

#322

Post by stevage »

fc417fc802 wrote: post #314
stevage wrote: post #289

Earlier quoted context omitted.

> And in all cases, if you produce the fuel using renewables then the CO2 output is trivially brought near zero. But...they don't.

But they could. Which generally means that objections of the form "we should cut back on [activity] because it produces too much CO2" are misplaced. The only activity we need to cut back on is the extraction of geological carbon.

Oh, good, glad that's solved then.

Re: “Beyond the limit”: Satellites and mirrors in space pose threat to the night sky

#323

Post by lstodd »

croes wrote: post #309
lstodd wrote: post #299

Earlier quoted context omitted.

What exactly do you propose to do with a 50m chondite coming our way?

We have agencies to handle that but they need to know it’s coming.

We have? I would like a short list of those. Last one I knew was X-COM from 1994 and that was fiction.

Re: “Beyond the limit”: Satellites and mirrors in space pose threat to the night sky

#324

Post by lstodd »

privong wrote: post #320
lstodd wrote: post #293

Earlier quoted context omitted.

Why not? They are massive only because you are limited by earth surface. In space there are no limits, see Radioastron for example, and that was decades ago. Right now for the price of that one project one could have a humongous radio telescope in orbit without any interference. If only people could really look forward.

> In space there are no limits, see Radioastron for example, and that was decades ago. Radioastron required cross-correlating the signal with ground-based radio teleacopes in order to do science. The collecting area, dish distributons, etc. would need to be fully replicated in space if one wanted to avoid using ground-based facilities entirely.

Nope. Ot was one of a kind thing only because you could not launch two at the time. With that a-given, ofc the ground-based "other end of the leg" was essential for it to work.

Now we can launch two. Or two dozen. This completely obviates any need for ground listeners as for resulting angular resolution.

Since ground-based radioastronomy has other uses, will stay there anyway and since crosscheck is always better, future long-base radiointerferometry will use legacy ground-based observatories.

Re: “Beyond the limit”: Satellites and mirrors in space pose threat to the night sky

#325

Post by privong »

lstodd wrote: post #324
privong wrote: post #320

Earlier quoted context omitted.

> In space there are no limits, see Radioastron for example, and that was decades ago. Radioastron required cross-correlating the signal with ground-based radio teleacopes in order to do science. The collecting area, dish distributons, etc. would need to be fully replicated in space if one wanted to avoid using ground-based facilities entirely.

Nope. Ot was one of a kind thing only because you could not launch two at the time. With that a-given, ofc the ground-based "other end of the leg" was essential for it to work. Now we can launch two. Or two dozen. This completely obviates any need for ground listeners as for resulting angular resolution. Since ground-based radioastronomy has other uses, will stay there anyway and since crosscheck is always better, fu…

We're saying the same thing -- one radioastron satellite isn't enough, you'd need a constellation of them.

Re: “Beyond the limit”: Satellites and mirrors in space pose threat to the night sky

#326

Post by Dig1t »

isthatafact wrote: post #319
Dig1t wrote: post #311

Earlier quoted context omitted.

Connectivity for the entire globe does more for progress. Millions of people have access to the wealth of human knowledge that wouldn’t otherwise have it (Africa, rural people around the world). Additionally, what we lose in visibility from earth we will more than gain in visibility from space telescopes, which will be funded by profits provided by LEO satellites. Any way you slice it, it’s a massive net increase in…

It does not need to be a choice between having internet or seeing stars at night. Also, telescopes on the ground can be made much bigger and more powerful than in space, so even if some satellite profits were somehow (magically?) directed toward space telescopes, losing the night sky would be bad for science.

>It does not need to be a choice between having internet or seeing stars at night.

It’s not, we’ll be able to see the stars no matter what. There are many millions of people who are getting real broadband access to the internet for the first time right now because of these satellites. It really does enable an entirely new way of living for people in rural areas, I see this myself firsthand every day. Many areas are just economically not feasible to run fiber cables to.

Cheap access to space means you can put space telescopes into orbits that provide views entirely unobtainable from earth. And with cheap access to space we can eventually put space telescopes which exceed the size of the largest ground telescopes which won’t have to deal with atmospheric interference or light pollution at all.

Starship will lower the cost to orbit by 15x. Making entirely new types of scientific missions economically viable including extremely large space telescopes.

Re: “Beyond the limit”: Satellites and mirrors in space pose threat to the night sky

#327

Post by retrochameleon »

Legend2440 wrote: post #22
edelbitter wrote: post #17

Earlier quoted context omitted.

Some scientific endeavors can be paused and maybe later relaunched, if funding has not dried up and temporarily-worthless machinery has not been left to rot. But stuff like mitigating the constant threat of big enough objects showing up on a collision course with earth should not be paused until those eye-catchers fall out of the sky. If there is something coming at us that can wipe out more than the stock price of o…

>the constant threat of big enough objects showing up on a collision course with earth I don't really think this is a serious risk. This is a once-in-a-million-years kind of event. Also, asteroid detection is not seriously affected by satellites. We can easily tell the difference between a moving satellite and a moving asteroid because of their speed.

Asteroid detection is certainly affected by satellites. The ever increasing number of satellites makes observations that normally detect asteroids very difficult. It is very easy to miss asteroids we would have seen otherwise if not for satellites giving off glare, reflections, and light. We don't just look for asteroids coming directly towards earth, we keep track of all sorts of large objects and their orbits in our solar system. The tracking authority is usually the IAUC Minor Planet Center.

Re: “Beyond the limit”: Satellites and mirrors in space pose threat to the night sky

#328

Post by retrochameleon »

bazodedo wrote: post #247
privong wrote: post #228

Earlier quoted context omitted.

There's at least two issues with this line of thinking: 1. many astronomical observations are long integrations (many minutes of open shutter) and you often cannot read out the pixels during the exposure. So you can't selectively ignore pixels on a "by moment" basis. And with enough satellites, enough pixels could be affected to render an entire image effectively unusable 2. It seems you're thinking only about optica…

How about putting our astronomy experiments into space as well? There'd be no light / em pollution there, as well as no atmospheric interference etc. and, 24/7 free power courtesy of our sun. Id expect orbital observatories to be superior to ground based ones, thinking of Webb, Hubble. I suppose the only downside is cost. So, the actual problem, is how to tax the shared resource that is our LEO. Aside from that, wed…

When science is already experiencing a funding stranglehold, how do you expect researchers to have access to do experiments in space?

Re: “Beyond the limit”: Satellites and mirrors in space pose threat to the night sky

#329

Post by snovv_crash »

m4rtink wrote: post #264
snovv_crash wrote: post #235

Earlier quoted context omitted.

Citizen initiatives are the only thing that can cut across partisan lines and stop politics from turning into tribal warfare.

Maybe fix the system so there are not just two parties & bad parties fail to be voted in?

Then you need combinatorial parties to support every possible political combination. Rather just have people vote on the policies themselves.

Re: “Beyond the limit”: Satellites and mirrors in space pose threat to the night sky

#330

Post by bit-anarchist »

omicronxt wrote: post #269
throwaway-11-1 wrote: post #221

Earlier quoted context omitted.

Yeah that’s totally fair and really good to see. It’s maybe the one perspective that gives me some hope

Our world in data is neoliberal think tank supported by billionares. They got bad reputation of misrepresenting data to favor capitalism as inherently progressive.

> Our world in data is neoliberal think tank

How so?

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