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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

#271

Post by antonvs »

ben_w wrote: post #112
afpx wrote: post #88

Earlier quoted context omitted.

In 1990 I hoped my grandkids would be able to join starfleet. After watching most of the gains go to the worst, I just hope they can escape the borg.

I was a kid in the 90s. Kinda surprised we got the (almost) universal translator before we got fusion.

You know what else we’re going to get before fusion? Everything. Commercially viable fusion energy is still a fantasy, essentially. Anyone who claims it’s only X years away is implicitly assuming that somehow, in those X years, we’ll find solutions to several fundamental problems that may not in fact have viable solutions.

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

#272

Post by notrealyme123 »

sajithdilshan wrote: post #261
notrealyme123 wrote: post #254

Earlier quoted context omitted.

> A new European Southern Observatory (ESO) study has found that current proposals to launch over 1.7 million satellites into orbit, including extremely bright ones, would have “devastating consequences for astronomy.” I have a hard time fitting your response to the posted article.

> A new European Southern Observatory (ESO) study has found that current proposals to launch over 1.7 million satellites into orbit, including extremely bright ones, would have “devastating consequences for astronomy.” According to the study, no more than 100 000 faint satellites, below naked eye visibility, should orbit Earth, to safeguard our ability to observe the night sky with modern telescopes Maybe you should…

ESO is not an EU agency. They don't write anything about regularisation.

I stand with my original comment.

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

#273

Post by Panzer04 »

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…

Radio telescopes are hilariously massive. I'm not sure it'd be easy to reproduce their capabilities in space?

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

#274

Post by sajithdilshan »

notrealyme123 wrote: post #272
sajithdilshan wrote: post #261

Earlier quoted context omitted.

> A new European Southern Observatory (ESO) study has found that current proposals to launch over 1.7 million satellites into orbit, including extremely bright ones, would have “devastating consequences for astronomy.” According to the study, no more than 100 000 faint satellites, below naked eye visibility, should orbit Earth, to safeguard our ability to observe the night sky with modern telescopes Maybe you should…

ESO is not an EU agency. They don't write anything about regularisation. I stand with my original comment.

Yeah you’re right, all the member countries are in African continent (https://www.eso.org/public/about-eso/memberstates/)

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

#275

Post by sajithdilshan »

zoilism wrote: post #4

For the first time in human history, the generations living now have been systematically robbed of their ancestral right to witness the night sky and its jaw-droppingly awe-inspiring magnificence.

Cry me a river

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

#276

Post by ACCount37 »

edelbitter wrote: post #17
xadhominemx wrote: post #5

I am a science and astronomy fan, but I am sorry, in this case progress is more important. If we regret our decision, the LEOs will fall out of the sky by themselves in a few years and it will be ok.

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…

This is why we have things like NEO Surveyor planned: space-based space rock detection.

That "particularly space-enthusiastic company" is a big part of why we're in a decent place for orbital defense right now. SpaceX has a lot of launchers, and a steady enough launch cadence that they can put a payload up there really fast, if there is a reason to hurry. Before, there was a very real risk of having to wait months just to get a launcher lined up - now, that's not nearly as much of a problem.

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

#277

Post by [deleted] »

Panzer04 wrote: post #273
bazodedo wrote: post #247

Earlier quoted context omitted.

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…

Radio telescopes are hilariously massive. I'm not sure it'd be easy to reproduce their capabilities in space?

[deleted]

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

#278

Post by lefra »

croes wrote: post #96
Legend2440 wrote: post #29

Earlier quoted context omitted.

No they don't. It's more of an issue for long-exposure galaxies and nebula. And asteroids are an extremely rare threat in the first place. It's literally a once-in-a-million-years kind of event.

Dinosaur killers? Yes. City killers? That size hits more often > Asteroids with a diameter more than 30–50 metres (100–150ft) are large enough to make it through our atmosphere intact, however, and the chance of this happening is estimated to be around once in every 100 years. > The damage from an impact of this size would be wide-ranging, and could wipe out an entire city if they were to impact a heavily populated a…

That "if it hits a populated area" reduces the probability by a factor 100 (because about 1% of the world's surface is urbanized [1]).

So the actual frequency of "city wiped" is more like once every 10000 years. Completely negligible compared to other city-wiping events (earthquakes or floods for example).

[1] https://en.wikipedia.org/wiki/File:Global_land_use_for_food_...

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

#279

Post by criddell »

mirashii wrote: post #206
nablaxcroissant wrote: post #46

I'm not sure how exactly they are making these calculations but I just don't see it. Both Reflect and SpaceX are targeting SSO orbits where they are only reflecting for an hour or two at sunset. That isn't true of Starlink, but that constellation is already up there and if its fine right now, I don't see it getting much worse as the materials on it get refined to be less problematic. More regulations would just have…

> that constellation is already up there and if its fine right now A lot of astronomers disagree.

And a lot of starlink customers agree.

How can this be resolved?

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

#280

Post by BenjiWiebe »

zoilism wrote: post #4

For the first time in human history, the generations living now have been systematically robbed of their ancestral right to witness the night sky and its jaw-droppingly awe-inspiring magnificence.

Did you know that if you stay up a bit later* than twilight, the satellites disappear?

*The later you stay up the more disappear, until the middle of the night. But they're most obvious shortly after dark.

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