# James Webb Space Telescope



## Foxbat (Dec 25, 2021)

James Webb: Hubble telescope successor faces 'two weeks of terror'
					

Nasa's huge new space observatory must survive a daunting series of deployments if it's to work.



					www.bbc.co.uk
				



Due to be launched today, I’d hate to be a scientist or engineer involved in this project right now. The article above describes ‘two weeks of terror’. This is the time taken to deploy the new telescope and there are 344 potential points of failure during this operation.

The best Xmas people on this project could get would be a successfull deployment but the stress must be immense right now so…to paraphrase another stressful moment in history….praise the lord and pass the valium

Fingers crossed.


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## CupofJoe (Dec 25, 2021)




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## AllanR (Dec 25, 2021)

Webb Is On Its Way! – James Webb Space Telescope
					






					blogs.nasa.gov


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## Foxbat (Dec 26, 2021)

A handy website








						Cosmic Cliffs - Webb Space Telescope  GSFC/NASA
					

The Latest NASA Released Webb Image is featured on this page. The James Webb Space Telescope's revolutionary technology will study every phase of cosmic history—from within our solar system to the most distant observable galaxies in the early universe. Webb’s infrared telescope will explore a...



					www.jwst.nasa.gov


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## CupofJoe (Jan 3, 2022)

Pretty pictures and a bit of an update...








						A $10bn 'glittering space jewel' begins its mission
					

A cleaned up video shows the James Webb telescope setting out on its quest to image the cosmos.



					www.bbc.co.uk


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## atsouthorn (Jan 3, 2022)

Foxbat said:


> A handy website
> 
> 
> 
> ...



The "Where is Webb?" page is brilliant

Where Is Webb?  NASA/Webb


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## Stephen Palmer (Jan 3, 2022)

All going well so far.
The potential benefits of this project for humanity are immense. I hope it's successful!


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## Parson (Jan 3, 2022)

This whole thing leaves me with my mouth hanging open. I have such a hard time believing that all of these immensely complicated things will roll out without an unfixable problem is a whole lot of faith to put in humans. Faith which I suspect is ill-placed.


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## BAYLOR (Jan 3, 2022)

Parson said:


> This whole thing leaves me with my mouth hanging open. I have such a hard time believing that all of these immensely complicated things will roll out without an unfixable problem is a whole lot of faith to put in humans. Faith which I suspect is ill-placed.



The more complex the tech , the more potential problems it has.


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## Foxbat (Jan 4, 2022)

The images from Hubble were absolutely stunning (including my personal favourite the pillars of creation), I wait with baited breath to see what this more powerful telescope will show us. 

And just in case you’ve never seen the pillars





Makes you feel so small….


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## mosaix (Jan 4, 2022)

The original spec was for the telescope to be operational for about ten years. However, the accuracy of the launch by the ESA Ariane 5 rocket was such that mid-course corrections have used much less fuel than planned.

This means that there is more fuel left than anticipated and the operational life has been extended to "significantly more than ten years".

This web page contains some interesting information regarding the implementation of the telescope.









						Where Is Webb?  NASA/Webb
					

During Webb's launch, deployment and commissioning, 'WhereIsWebb' tracked Webb's 'flight' to L2 orbit, its state and progress during its deployment and commissioning process, and finally the release of its first images. This process is now complete. During this process, the page constantly...



					jwst.nasa.gov


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## Parson (Jan 4, 2022)

Webb had some minor problems but so far everything is working and on schedule. The heat shield, one of the critical areas of concern has been deployed and the beat goes on.


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## Omits (Jan 4, 2022)

Stephen Palmer said:


> All going well so far.
> The potential benefits of this project for humanity are immense. I hope it's successful!


OK so what are the potential benefits?


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## Foxbat (Jan 5, 2022)

This article gives a few examples.








						How Astronomy Benefits Society and Humankind
					

With an annual cost of $30.8 million, the Keck Observatory costs $53.7 thousand for a single night’s worth of operation. It will cost the James Webb Space Telescope approximately $8.8 billion to reach orbit. And the Space Launch System that will carry the Orion capsule is expected to cost $38...




					www.universetoday.com


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## Justin Swanton (Jan 5, 2022)

Foxbat said:


> This article gives a few examples.
> 
> 
> 
> ...


Interesting. Most of the benefits consist of tech designed for astronomy that found concrete application elsewhere. I still wonder why so much money is used on launching satellites that are purely gatherers of information with little practical value to us. Bar some drastic alterations of the laws of physics, we aren't going to colonise the solar system, never mind the galaxy. So we are spending huge amounts of money learning more about a cosmos we will never personally interact with.

It's a bit like the Hadron Collider: it cost $4,4 billion to build and studies the behaviour of subatomic particles. Very much a case of theoretical knowledge with little or no practical application. As far as I know (feel free to correct me) our understanding of the building blocks of matter has long since outstripped our ability to make any technological use of that understanding. It's now purely knowledge for knowledge's sake. Does that justify spending billions of dollars? It seems odd to me.

I suspect there is more than just scientific inquiry going on here. Do we need to feel that science and technology are in a constant state of progress that will continue indefinitely? That the envelope will continue to be pushed, forever?


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## Justin Swanton (Jan 5, 2022)

BTW space is the perfect place for machines. If a satellite is well-designed there is virtually nothing that can compromise its functioning since its environment remains absolutely simple and constant - wear and tear is non-existent. Hence the extraordinary success of so many satellite missions where the satellite was able to operate well past its expected expiry date. If we could turn ourselves into robots then the galaxy (or at least the solar system) would be ours.


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## Ursa major (Jan 5, 2022)

Justin Swanton said:


> Bar some drastic alterations of the laws of physics, we aren't going to colonise the solar system


You are right that the laws of physics aren't going to change...

...but then they didn't change before, but this hasn't stopped us from developing technologies that utilise our ever-growing understanding of what those laws are and mean.

On the other hand, ignorance, and a lack of will to overcome our ignorance, can stop us dead in our tracks.


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## Stephen Palmer (Jan 5, 2022)

Omits said:


> OK so what are the potential benefits?


One premier league British football club spent one sixth of the cost of the James Webb telescope on players over ten years. Does that answer your question?


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## Stephen Palmer (Jan 5, 2022)

Nice post, @mosaix! Thx.


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## Pyan (Jan 5, 2022)

Omits said:
			
		

> OK so what are the potential benefits?



Michael Faraday, when asked what use all this work on electricity was, replied: *“Of what use is a newborn baby?”*

And don't forget what Sir William Preece, (Chief Engineer, British Post Office, 1878) said:
*"The Americans have need of the telephone, but we do not. We have plenty of messenger boys."*


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## CupofJoe (Jan 5, 2022)

We don't know what we don't know.
I think a fundamental part of humanities psyche is to ask Why? What's over there? How does that work? Is that edible?
And then go and find out.
Call it innate curiosity. Not everyone has it to the same degree. In some people it will manifest as climbing mountains. In others it will be looking for the perfect equation.
And we don't know the unintended consequences of those actions or gained knowledge.


Justin Swanton said:


> BTW space is the perfect place for machines. If a satellite is well-designed there is virtually nothing that can compromise its functioning since its environment remains absolutely simple and constant - wear and tear is non-existent. Hence the extraordinary success of so many satellite missions where the satellite was able to operate well past its expected expiry date. If we could turn ourselves into robots then the galaxy (or at least the solar system) would be ours.


If you ignore the stress of launch, the variations in temperature and the occasional doses of immense amounts of radiation.


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## Foxbat (Jan 5, 2022)

Justin Swanton said:


> So we are spending huge amounts of money learning more about a cosmos we will never personally interact with



We personally interact with the cosmos all the time. We live and survive on a planet created within the cosmos and are constantly bombarded with particles from that very same cosmos. It was from the cosmos that an asteroid that (allegedly) wiped out the dinosaurs came and made way for us. Furthermore, those bombarding pariticles may well have played a part in the evolutionary path we took.

Maybe, subconsciously, we’re just looking for a way to go home.

 As the song goes….we are stardust.


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## Brian G Turner (Jan 5, 2022)

I'm going to move this thread to the Science section, as we're going to see some great scientific discoveries using the JWST - I'm especially looking forward to deeper understanding of the exoplanets out there.


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## Justin Swanton (Jan 5, 2022)

Pyan said:


> Michael Faraday, when asked what use all this work on electricity was, replied: *“Of what use is a newborn baby?”*


And he then went on to invent the electric motor. He is a classic case of theoretical research moving fast to practical application.



> And don't forget what Sir William Preece, (Chief Engineer, British Post Office, 1878) said:
> *"The Americans have need of the telephone, but we do not. We have plenty of messenger boys."*


A reaction by an ignoramus to a practical invention.


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## Justin Swanton (Jan 5, 2022)

Stephen Palmer said:


> One premier league British football club spent one sixth of the cost of the James Webb telescope on players over ten years. Does that answer your question?


For me it's just another manifestation of lunacy. £190 million for a single player, Neymar, transferred from Barcelonia to Paris Saint-Germain in 2017! I don't get it but that's just me.

There again it's nothing new. If a gladiator survived his career he could retire as one of the richest men in Rome.


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## Justin Swanton (Jan 5, 2022)

CupofJoe said:


> If you ignore the stress of launch, the variations in temperature and the occasional doses of immense amounts of radiation.


The first is a one-off, the second means the extremes of sunlight or shade and satellites are designed with that in mind, and the third applies only to those satellites that pass close to a source of immense radiation like Jupiter and, again, they are built to withstand it. The things in space that can affect a satellite are few, well understood and easily catered for. It's not like the surface of the Earth where atmosphere, humidity, dust, living organisms, etc. inevitably limit the lifespan of a machine, especially something as complex and fragile as a satellite.


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## Brian G Turner (Jan 5, 2022)

Everything continues to unfold smoothly - but if I had worked on this I'd still be nervous!








						Webb telescope fully deploys sunshield in mission milestone
					

The James Webb Space Telescope fully deployed its tennis-court sized sunshield Tuesday, a critical milestone for the success of its mission to study every phase of cosmic history, NASA said.




					phys.org


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## Wayne Mack (Jan 5, 2022)

Justin Swanton said:


> Do we need to feel that science and technology are in a constant state of progress that will continue indefinitely? That the envelope will continue to be pushed, forever?


I say, yes. I would find it boring to live in a world where everything was explained, where there is nothing new to be discovered, where there is no sense of wonder. I agree that there are practical things that humanity can and should expend time and effort on, but what may be the defining characteristic of mankind is the search for knowledge for which practical use is currently unknown and may never be discovered. Man has often wondered how it all began and now there is an opportunity to test the ideas, to prove and disprove, and fundamentally alter our understanding. The various experiments are evidence that men can actually do wonderous things, despite repeated evidence in our daily lives that we fall short in many of our most basic tasks. The quest for increased understanding of what may never be fully understood is what can give us hope.


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## Wayne Mack (Jan 5, 2022)

Justin Swanton said:


> If a satellite is well-designed there is virtually nothing that can compromise its functioning since its environment remains absolutely simple and constant - wear and tear is non-existent.


Entropy still exists. An orbiting satellite is in a constant state of free fall; without some sort of altitude boost, all satellites fall to Earth. Energy conversion and storage degrade over time. Satellites are frozen in their technical capabilities; what was launched years ago falls short of what we could ask of the devices today. The ones launched today will fall short in answering the questions of the future.


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## Foxbat (Jan 5, 2022)

The solar system is full of dust that can damage satellites





						Dust particles cause problems for satellites
					

A speck of debris is all it takes to knock out spacecraft electronics TINY particles of dust pose a more serious risk to satellites than huge lumps of space junk, […]




					www.spaceref.com


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## Pyan (Jan 5, 2022)

Not forgetting Elon Musk...

China complains to UN after maneuvering its space station away from SpaceX Starlink satellites


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## Foxbat (Jan 5, 2022)

I wonder when Uber Stellar  will start picking up satellites….

Meanwhile, latest news (and it's good so far)








						James Webb Space Telescope: Sun shield is fully deployed
					

The unfurling of the observatory's giant sun shade is a major milestone for the $10bn mission.



					www.bbc.co.uk


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## mosaix (Jan 5, 2022)

Secondary mirror now locked in place.  









						James Webb Space Telescope extends secondary mirror
					

Another major milestone for the $10bn observatory as its secondary mirror is locked into position.



					www.bbc.co.uk


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## Pyan (Jan 6, 2022)

Let's keep the discussion on the scientific aspect of this, please, and try not to be tempted to stray into metaphysics rather than physics.


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## Foxbat (Jan 6, 2022)

According to this article (if I’ve understood it correctly), the next deployment will be the side-wings of the primary mirror. Then, it looks like not a lot happening for a month during cooldown. I’d be far too impatient for this waiting malarky.





						James Webb Space Telescope Post-Launch Deployment Timeline
					






					webbtelescope.org


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## Venusian Broon (Jan 6, 2022)

Foxbat said:


> According to this article (if I’ve understood it correctly), the next deployment will be the side-wings of the primary mirror. Then, it looks like not a lot happening for a month during cooldown. I’d be far too impatient for this waiting malarky.
> 
> 
> 
> ...



Be patient and try not to worry    

On a positive note, I heard that the launch was extremely well executed by the Ariane rocket and team, therefore the number of corrections required by the telescope to get it into the correct flightpath was much less than expected. Hence that means that the telescope has much more fuel than expected. Therefore they are projecting that the lifetime of the telescope has about doubled to 10 years. Which is fantastic news. 

Only need the remaining 100 or so critical mission steps to go without a hitch!


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## Justin Swanton (Jan 6, 2022)

Foxbat said:


> According to this article (if I’ve understood it correctly), the next deployment will be the side-wings of the primary mirror. Then, it looks like not a lot happening for a month during cooldown. I’d be far too impatient for this waiting malarky.


Good hits take time. Ask any Corleone. Except Sonny. Don't ask Sonny.


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## mosaix (Jan 6, 2022)

Venusian Broon said:


> Be patient and try not to worry
> 
> On a positive note, I heard that the launch was extremely well executed by the Ariane rocket and team, therefore the number of corrections required by the telescope to get it into the correct flightpath was much less than expected. Hence that means that the telescope has much more fuel than expected. Therefore they are projecting that the lifetime of the telescope has about doubled to 10 years. Which is fantastic news.
> 
> Only need the remaining 100 or so critical mission steps to go without a hitch!



I seem to remember the original lifetime was estimated to be ten years and that the extra fuel will extend it beyond that.


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## Venusian Broon (Jan 6, 2022)

mosaix said:


> I seem to remember the original lifetime was estimated to be ten years and that the extra fuel will extend it beyond that.



NASA had stated 5 years as the minimum time they expected, although they had given a range of up to 10 years, as I assume they were building into that range all sorts of eventualities because of the launch and other factors, and the lower figure was the one that most people seemed to be banding about just before the launch. At least of all the people that I listened to or read. 

Now they have confirmed that the 10 year minimum is now very likely, and yes, there could still be fuel for more time after that (although one must point out that: "_The space agency warns, however, that 'many factors' could ultimately affect JWST’s lifespan_.")


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## Parson (Jan 6, 2022)

Maybe in 10-20 years they could refuel it. I believe I read that it was designed with that possibility in mind.


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## mosaix (Jan 7, 2022)

Port primary mirror wing deployed and latched. 

So much credit is due to the people who have worked on this.


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## atsouthorn (Jan 8, 2022)

It's fascinating, isn't it? I couldn't imagine having to cater for all the things that could go wrong and creating fixes and safeguards to pre-empt these issues. Is this what sending your children off to university feels like?


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## Justin Swanton (Jan 8, 2022)

The accuracy of the launch and flight path means that the satellite has more fuel in reserve than originally expected, so 10 years is a real possibility.

Edit: just realised this pretty much duplicates Venusian Broon's post.


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## Foxbat (Jan 8, 2022)

I was curious given that the Hubble has been up for 30 (twice its estimated lifespan) so did a little digging about Webb. Apparently, because it’s so far out, it will have to burn fuel occasionally for ‘station keeping’. I’m assuming Hubble being closer didn’t have this problem (at least not to the same extent). Also, Webb’s distance from Earth will, it seems, make it impossible to carry out maintenance or repair.

So, with all that, I finally understand how crucial this precision launch has been


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## Ambrose (Jan 8, 2022)

15.02 GMT  The second panel of the Wevv is being unfolded live on NASA tv.


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## Venusian Broon (Jan 8, 2022)

Foxbat said:


> I was curious given that the Hubble has been up for 30 (twice its estimated lifespan) so did a little digging about Webb. Apparently, because it’s so far out, it will have to burn fuel occasionally for ‘station keeping’. I’m assuming Hubble being closer didn’t have this problem (at least not to the same extent). Also, Webb’s distance from Earth will, it seems, make it impossible to carry out maintenance or repair.
> 
> So, with all that, I finally understand how crucial this precision launch has been


It's at the L2 Lagrange point so that can use the Earth to help shield it from the sun, but this point is unstable so it will be constantly being nudged out of its optimum position (on a timescale of 23 days apparently). Hence the need for fuel to nudge it back into the correct position. 

Yes it's a bit too far out for maintenance trips, but as @Parson  points out if it lasts more than 10 years, who know what sort of ship/tech we might have!


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## Justin Swanton (Jan 8, 2022)

Venusian Broon said:


> Yes it's a bit too far out for maintenance trips, but as @Parson  points out if it lasts more than 10 years, who know what sort of ship/tech we might have!


My guess is a robotic maintenance satellite. Robotics is up-and-coming technology - well up to the job by 2032 and will be an order of magnitude cheaper than sending astronauts out there.


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## mosaix (Jan 8, 2022)

Primary mirror unfolding completed. 









						Nasa engineers complete the unfolding of the James Webb space telescope
					

‘Time machine’ will allow astronomers to study the beginning of the universe shortly after the Big Bang




					www.theguardian.com


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## Foxbat (Jan 9, 2022)

Venusian Broon said:


> It's at the L2 Lagrange point so that can use the Earth to help shield it from the sun, but this point is unstable so it will be constantly being nudged out of its optimum position (on a timescale of 23 days apparently). Hence the need for fuel to nudge it back into the correct position.
> 
> Yes it's a bit too far out for maintenance trips, but as @Parson  points out if it lasts more than 10 years, who know what sort of ship/tech we might have!


I’ve read somewhere that it might be possible to produce an artificial lagrange point by using two spacecraft. I wonder, therefore,  if it might be possible some time in the future to send out another satellite to act like a kind of cosmic counterweight and increase Webb’s stability that way?


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## Venusian Broon (Jan 9, 2022)

Foxbat said:


> I’ve read somewhere that it might be possible to produce an artificial lagrange point by using two spacecraft. I wonder, therefore,  if it might be possible some time in the future to send out another satellite to act like a kind of cosmic counterweight and increase Webb’s stability that way?


Interesting, would love to see the idea. Off the top of my head, the centre of mass of the two satellite system would still behave like a single mass, and being much, much lighter than the Earth and Sun would still wander off, but no doubt I'm missing something!


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## Aknot (Jan 9, 2022)

Justin Swanton said:


> It's a bit like the Hadron Collider: it cost $4,4 billion to build and studies the behaviour of subatomic particles. Very much a case of theoretical knowledge with little or no practical application. As far as I know (feel free to correct me) our understanding of the building blocks of matter has long since outstripped our ability to make any technological use of that understanding. It's now purely knowledge for knowledge's sake. Does that justify spending billions of dollars? It seems odd to me.



In most cases basic research is done to further our knowledge and understanding. However, without it we would not have the science, technology, medicine etc that we have today. 

It’s already a struggle for many fields that basic research does not have the funding it needs nor attracts enough researchers. Mainly due to the question you ask: what’s the use of it. But if all research was specialized it would leave gaps in our understanding that down the line will hinder further steps. Plus the fact that specialized research often means proprietary results while basic research tends to be shared for the betterment of all. However, we’re approaching the dreaded political part of this discussion so I’ll leave it there


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## mosaix (Jan 9, 2022)

The human race has got to where it is partly because we have quest for knowledge.


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## Foxbat (Jan 10, 2022)

I thought this was a good article for us astronomical ignoramuses








						James Webb telescope completes epic deployment sequence
					

With the unpacking of its big mirror, the $10bn telescope is on track to begin its historic mission.



					www.bbc.co.uk
				




This, I thought, was an exciting quote from the leader of the mirror development team
"Webb is so powerful, almost anywhere we look we're going to be breaking new ground in a huge way,"


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## Brian G Turner (Jan 10, 2022)

Foxbat said:


> I thought this was a good article for us astronomical ignoramuses
> 
> 
> 
> ...



I was just coming to post that link - great piece. And so impressive it's all working so far, as so many things could have gone wrong. Really looking forward to deeper insights on exoplanets once it's in position and fully running.


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## Justin Swanton (Jan 10, 2022)

Brian G Turner said:


> I was just coming to post that link - great piece. And so impressive it's all working so far, as so many things could have gone wrong. Really looking forward to deeper insights on exoplanets once it's in position and fully running.


I'm looking forward to that too. Don't take any cold water I've splashed around as a lack of enthusiasm for the project. The universe is a fascinating place.


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## Foxbat (Jan 10, 2022)

Brian G Turner said:


> I was just coming to post that link - great piece. And so impressive it's all working so far, as so many things could have gone wrong. Really looking forward to deeper insights on exoplanets once it's in position and fully running.


I think what helped me the most in this article was understanding the importance of  the sun shield. I thought the analogy of trying to see the flames from a match against a backdrop of a burning haystack explained the problem perfectly

Re the Concorde analogy made in a recent post….I hate flying but love Concorde. I’m lucky enough to have one sited in a museum a mere five or so miles from my home. I never thought I‘d get to go inside one of these awesome jets on my wages

Highly recommended for anybody who loves engineering


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## Brian G Turner (Jan 11, 2022)

There's a video on YouTube showing it unfolding:





Looks quite simple, but there are around 400 pulleys involved in that, and goodness knows what the effect of just one of those breaking would have had.


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## mosaix (Jan 11, 2022)

The focussing of each individual mirror comes next. That involves six (I think) motors attached to the rear of each mirror to pull it into shape. Each motor has to be heated before it can be used. Then the mirror as a whole is focussed. 

It's incredible that, so far, each individual component of the many hundreds involved has worked faultlessly.


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## mosaix (Jan 11, 2022)

Okay, here's something I don't understand.

The Webb telescope will be able to pick up signals from the earliest time in the formation of the universe. Those signals have been traveling towards us for billions of years. That means we're billions of light-years away from the source of the signals. How, if we aren't traveling at the speed of light, has there been enough time for us to get so far away? 

Or to put it another way, if those signals are traveling at the speed of light, how come they didn't pass us years ago? How come they're only just catching up with us now?


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## Justin Swanton (Jan 11, 2022)

Brian G Turner said:


> There's a video on YouTube showing it unfolding:
> 
> 
> 
> ...


My guess is that there is a certain amount of redundancy built in - if a few pulleys malfunction the others can take over their job in order to ensure the tasks get done,. and vice versa. The whole project isn't a bust just because one pulley motor doesn't work.


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## Parson (Jan 11, 2022)

Justin Swanton said:


> My guess is that there is a certain amount of redundancy built in - if a few pulleys malfunction the others can take over their job in order to ensure the tasks get done,. and vice versa. The whole project isn't a bust just because one pulley motor doesn't work.


Maybe, but it was said that there were 300 something single point failures, that if this one thing didn't work as planned the mission was a bust. And I know that several of those were part of the unfolding.


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## Venusian Broon (Jan 12, 2022)

mosaix said:


> Okay, here's something I don't understand.
> 
> The Webb telescope will be able to pick up signals from the earliest time in the formation of the universe. Those signals have been traveling towards us for billions of years. That means we're billions of light-years away from the source of the signals. How, if we aren't traveling at the speed of light, has there been enough time for us to get so far away?
> 
> Or to put it another way, if those signals are traveling at the speed of light, how come they didn't pass us years ago? How come they're only just catching up with us now?


Assuming that the big bang and current standard model we are using at the moment, is more or less correct...

...currently our estimate for the size of the _observable _universe is a sphere with a radius of about 46 billion light years around us. Which you will note is much bigger than 13.8 billion - which is roughly our estimate for the age of the universe. How can we see something 46 billion light years away if there has only been 13.8 billion years? 

This disparity is caused by the expansion of the universe, which has been continually occurring since the start (very fast right at the start with inflation - a long bit of slower expansion afterwards - and, we currently believe, dark energy now accelerating it) 

This expansion has two impacts. First, it increases the distance between objects and the bigger the distance between the two objects the faster the expansion - this expansion is a function of space-time, not a force on matter and photons etc. And space-time does not need to observe the constraint of the speed of light. Thus we suspect that the real universe is many times bigger than we can observe, because beyond a certain point the very distant universe would be expanding so fast that light emitted in a very distant part would never be able to reach us. 

The second is that any photons emitted will get 'stretched' by this expansion and become red-shifted. Thus the earliest 'object' we can see is the cosmic microwave background radiation, which is the burst of light that decoupled when the universe cooled enough for neutral hydrogen to form - about 370,000 years after the big bang. At the time I believe it was a blackbody radiation at about 3000K. It is now a blackbody radiation of about 2.7K. In wavelength terms the photons have been stretched just over 1000 times in wavelength. 

Thus the possibility that the James Webb telescope might see objects that formed in the very early universe - such as population III stars, because all the light emitted at that time will have been redshifted to infrared/microwave. 


So TL;DR: 

The expansion of the universe means that we are only _now_ getting light from certain parts of the universe, and it is these areas that we can see as they were at the earliest times. 

Confusingly these areas are now much further away in real distance than the lifetime of the universe, but this can be accounted for by the expansion of the universe as well. 


If you want a simple analogy. Think of a balloon that can be blown up indefinitely. Mark two spots on it. They are, say, galaxies A and B. The expansion of the universe is this balloon inflating constantly and getting bigger. As it does so the distance between A and B gets bigger. Now train an ant to walk between A and B at a constant speed - think of that as a photon being emitted from A towards B! As the expansion increases the distance the ant is still stuck at walking at the same speed, therefore will take longer to reach B.


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## mosaix (Jan 12, 2022)

Venusian Broon said:


> Assuming that the big bang and current standard model we are using at the moment, is more or less correct...
> 
> ...currently our estimate for the size of the _observable _universe is a sphere with a radius of about 46 billion light years around us. Which you will note is much bigger than 13.8 billion - which is roughly our estimate for the age of the universe. How can we see something 46 billion light years away if there has only been 13.8 billion years?
> 
> ...


Excellent. Many thanks.


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## mosaix (Jan 13, 2022)

Nasa begins months-long effort to focus James Webb space telescope
					

The revolutionary new scope could provide a glimpse of the cosmos dating back billions of years, but first some painstaking adjustments are needed




					www.theguardian.com


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## Pyan (Jan 25, 2022)

Well, it's finally in the right place, at least. Just hope that all the final unfolding goes to plan!









						James Webb telescope parked in observing position
					

The $10bn successor to Hubble is parked a million miles from Earth after a 30-day journey from Earth.



					www.bbc.co.uk


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## Foxbat (Jan 25, 2022)

Just another five months to go until we get the first result…talk about long exposure


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## BT Jones (Jan 25, 2022)

Facebook asked me if I wanted to join a FB group on the JWT.  Irrespective of how it ascertained my interest (presumably somehow accessing the stories I read on the BBC website), I said yes.

Really looking forward to some stunning images.


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## Venusian Broon (Jan 30, 2022)

Nice summary of what to expect from the telescope


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## mosaix (Feb 11, 2022)

I receive a notification from the New Scientist app that the telescope has sent back its first picture - of itself. Disappointingly the New Scientist website has no further info and I can't find anything related on the web.

Anyone heard anything?

Update: just found this:









						James Webb Space Telescope just sent back its first image - of itself
					

NASA engineers working to align the 18 hexagonal mirrors of the James Webb Space Telescope have released its first pictures. One shows the same star appearing 18 times, while a camera also took a 'selfie' of the mirrors




					www.newscientist.com


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## Venusian Broon (Feb 11, 2022)

mosaix said:


> I receive a notification from the New Scientist app that the telescope has sent back its first picture - of itself. Disappointingly the New Scientist website has no further info and I can't find anything related on the web.
> 
> Anyone heard anything?
> 
> ...



All my astronomy channels are going full tilt! Dr Becky here explains in a bit more depth:


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## Elckerlyc (Feb 11, 2022)

Well, 18 mirrors, 18 stars. That's good news.


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## Parson (Feb 11, 2022)

Yes, only good news here. This is such an impressive feat of engineering it boggles the mind.


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## Stephen Palmer (Feb 12, 2022)

Amazing. Good news indeed.


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## Foxbat (Feb 13, 2022)

A somewhat frivolous question but is this Webb selfie the furthest selfie taken in space? Or did Voyager have a selfie capability?


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## Elckerlyc (Feb 13, 2022)

Selfies weren't invented yet in those days.


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## Venusian Broon (Feb 13, 2022)

Foxbat said:


> A somewhat frivolous question but is this Webb selfie the furthest selfie taken in space? Or did Voyager have a selfie capability?


I think not. But I don't think Voyager had the ability to take pictures that had itself in it.

But, I'm pretty sure a Venus probe took a selfie of itself...Just checked, it took it while passing Venus, it was on way to Mercury!









						BepiColombo Spacecraft Headed for Mercury Takes a Photo with Venus Along the Way
					

The European-Japanese spacecraft BepiColombo has taken a selfie with Venus on its way to another planet, Mercury.




					www.techtimes.com
				




Another Japanese mission that was there to test solar sails (and also in the vicinity of Venus I believe, and I think this was the one I was thinking of) also had a small camera orbit the spacecraft and took piccies









						Mini-camera pictures Japan's Ikaros solar sail
					

A small free-floating camera returns images of Japan's solar sail, Ikaros, in flight.



					www.bbc.co.uk
				




What about the rovers on Mars? They are probably, in general, further away from Earth.


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## Parson (Feb 14, 2022)

The Mars rovers are *much* further from earth.


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## Lumens (Feb 16, 2022)

Does the Pale Blue Dot picture qualify as a selfie?









						Voyager 1's Pale Blue Dot | NASA Solar System Exploration
					

The Pale Blue Dot is a photograph of Earth taken Feb. 14, 1990, by NASA’s Voyager 1 when it was 3.7 billion miles (6 billion kilometers) from the Sun.




					solarsystem.nasa.gov


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## Justin Swanton (Feb 16, 2022)

Lumens said:


> Does the Pale Blue Dot picture qualify as a selfie?
> 
> 
> 
> ...


Of course! A long selfie stick...


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## mosaix (Mar 4, 2022)

Spacewatch: Nasa’s Webb telescope mirror alignment continues
					

Seven-step process to enable segments to work as a single mirror nears halfway point




					www.theguardian.com
				




Three of the seven stages of mirror alignment completed.


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## Parson (Mar 4, 2022)

This whole thing absolutely blows me away. I try to imagine how these machines can function correctly in such utter cold when even -25 (f) weather here means everything is slow and brittle.


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## mosaix (Mar 16, 2022)

James Webb: 'Fully focused' telescope beats expectations
					

Engineers align the mirrors of the $10bn observatory to produce a pin-sharp image of a star.



					www.bbc.co.uk


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## mosaix (Mar 17, 2022)

Nasa image of star photobombed by thousands of ancient galaxies
					

Picture is a test shot to see how a new telescope’s 18 hexagonal mirrors work together for a single coordinated image




					www.theguardian.com


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## psikeyhackr (Mar 18, 2022)

Parson said:


> This whole thing absolutely blows me away. I try to imagine how these machines can function correctly in such utter cold when even -25 (f) weather here means everything is slow and brittle.



This is the absurdity of our technological society. We can land robots on Mars with skyhooks but the automobile industry cannot provide reliability and durability data on the products they have manufactured for 100 years.

I have never owned a new car or been to an auto show since the Moon landing.


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## Justin Swanton (Mar 18, 2022)

Parson said:


> This whole thing absolutely blows me away. I try to imagine how these machines can function correctly in such utter cold when even -25 (f) weather here means everything is slow and brittle.


I suppose one could call it cool tech. ;-)


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## Parson (Mar 18, 2022)

psikeyhackr said:


> but the automobile industry cannot provide reliability and durability data on the products they have manufactured for 100 years.


Two words: "Planned Obsolescence." 

--- If your cars break after 10 years or so it's easy to sell another one.


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## psikeyhackr (Mar 18, 2022)

Parson said:


> Two words: "Planned Obsolescence."
> 
> --- If your cars break after 10 years or so it's easy to sell another one.



And why we will have +3 degrees C by 2100.


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## Parson (Mar 18, 2022)

psikeyhackr said:


> And why we will have +3 degrees C by 2100.


I suppose you could take a more optimistic view and say that's why we will be all electric decades sooner because cars don't last 50 years like they should. --- But that's really reaching for something positive.


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## Ambrose (Mar 18, 2022)

But it just might be negative.


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## mosaix (Mar 19, 2022)

psikeyhackr said:


> This is the absurdity of our technological society. We can land robots on Mars with skyhooks but the automobile industry cannot provide reliability and durability data on the products they have manufactured for 100 years.



I suppose that if each car cost a billion dollars it would perform better and last a lot longer than the ones we are used to.


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## BAYLOR (Mar 19, 2022)

mosaix said:


> I suppose that if each car cost a billion dollars it would perform better and last a lot longer than the ones we are used to.



Yes,  the car the lasts forever , the one billion dollar indestructible mobile , options not included .


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## psikeyhackr (Mar 19, 2022)

mosaix said:


> I suppose that if each car cost a billion dollars it would perform better and last a lot longer than the ones we are used to.



Nonsensical complaint. Satellites and space probes must be super reliable since no one can go to repair them. That does not mean that manufacturers don't know how to make very reliable products for use on Earth that can be fixed here. Plus they do not need to be redesigned every year. There is also no reason why economists do not report the annual depreciation of automobiles since WWII.

Marketing encourages consumers to be stupid.

GDP is BS!


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## Brian G Turner (Mar 20, 2022)

Back to the James Webb telescope please.


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## mosaix (May 1, 2022)

James Webb Space Telescope in final stretch
					

The $10bn successor to Hubble is fully focussed and aligned. It's close now to starting work.



					www.bbc.co.uk


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## Quokka (May 1, 2022)

So great to see the JWST finally launched and close to active duty. I remember discussing this in one of my first ever classes as a teacher in 2015/16, at the time it was projected to launch in 2018 and I told the class that history would suggest it would get pushed back, possibly a few times but still to keep an eye out for when it launches and then later starts sending pictures back. I wonder if any students have seen it mentioned (or will do during its lifespan) and vaugely remember a high school science class from way way back.


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## mosaix (Jul 8, 2022)

7 big questions the James Webb Space Telescope is about to answer
					

NASA will release the first full-colour images from the James Webb Space Telescope next week. Here’s what it will be looking at first – and how it could address the biggest mysteries of the universe




					www.newscientist.com
				




ON 12 JULY, the James Webb Space Telescope (JWST) will release its first scientific images, raising the curtain on a new era in astronomy. After years of delays, a suspenseful launch and months of testing, the most powerful telescope ever made is finally ready to gather fresh clues relating to questions we could only dream of answering with its predecessors.


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## Brian G Turner (Jul 8, 2022)

NASA have released a "teaser" from an early engineering test:








						NASA releases James Webb telescope 'teaser' picture
					

NASA has a provided a tantalizing teaser photo ahead of the highly-anticipated release next week of the first deep-space images from the James Webb Telescope—an instrument so powerful it can peer back into the origins of the universe.




					phys.org
				




Certainly looks very detailed!


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## psikeyhackr (Jul 8, 2022)

mosaix said:


> ON 12 JULY, the James Webb Space Telescope (JWST) will release its first scientific images, raising the curtain on a new era in astronomy. After years of delays, a suspenseful launch and months of ], the most powerful telescope ever made is finally ready to gather fresh clues relating to questions we could only dream of answering with its predecessors.


AWAwawwaaa Man! NO eyeglasses for the mirror?


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## Parson (Jul 8, 2022)

We are so lucky to be living in the days of this telescope. To quote the good Dr. --- Dr. Seuss, "O the wonders you will see."


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## psikeyhackr (Jul 9, 2022)

Can Boldly

"look where no telescope has looked before."

AHAHAhahaaa! It's Klingons!


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## Harpo (Jul 11, 2022)

I’ve started watching the countdown until the first images









						Countdown to Webb's 1st Images  Webb/NASA
					

Countdown to the release NASA's Webb Space Telescope 1st first full-color images and spectroscopic data.  The James Webb Space Telescope (sometimes called Webb or JWST) is a large infrared telescope with a 6.5-meter primary mirror.  Webb will be the premier observatory of the next decade...



					www.jwst.nasa.gov


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## psikeyhackr (Jul 11, 2022)

Harpo said:


> Countdown to Webb's 1st Images  Webb/NASA
> 
> 
> Countdown to the release NASA's Webb Space Telescope 1st first full-color images and spectroscopic data.  The James Webb Space Telescope (sometimes called Webb or JWST) is a large infrared telescope with a 6.5-meter primary mirror.  Webb will be the premier observatory of the next decade...
> ...


That is hilarious.


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## mosaix (Jul 11, 2022)

How the James Webb Space Telescope's first colour images were made
					

Joseph DePasquale, the lead image processor for the James Webb Space Telescope, says seeing its first colour picture was an "overwhelming" experience




					www.newscientist.com
				




_Later today, President Joe Biden will unveil the first full-colour image captured by the James Webb Space Telescope (JWST) – with a batch of additional images set for release tomorrow. We know the first image is called “Webb’s First Deep Field” and will provide us with the deepest and highest resolution image of the universe yet captured. Tomorrow’s release will include a view of the spectacular Carina Nebula and a distant group of galaxies known as Stephan’s Quintet._


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## Brian G Turner (Jul 12, 2022)

The BBC shows the first image, and does a nice comparison with the same view from Hubble:









						James Webb telescope takes super sharp view of early cosmos
					

The new $10bn space telescope delivers its first full-colour image of the distant Universe.



					www.bbc.co.uk


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## Foxbat (Jul 12, 2022)

The comparison is quite impressive and really shows the extra detail now available


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## mosaix (Jul 12, 2022)

James Webb telescope takes super sharp view of early cosmos
					

The new $10bn space telescope delivers its first full-colour image of the distant Universe.



					www.bbc.co.uk
				




See the foot of the article for details of today’s broadcasts re the latest images.


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## LostCosmonaut (Jul 12, 2022)

*Very* sharp! I appreciate the comparison with Hubble in the BBC article, it really shows how much of a step up Webb is.


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## Parson (Jul 12, 2022)

I've been having this thought that the JWST is the kind of thing that we could have read about in SF stories. One race working to detect another with deep space instruments. I'm absolutely gob-smacked with this level of tech. I wouldn't have thought that we could pull it off.


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## Christine Wheelwright (Jul 12, 2022)

It reminds me of the Total Perspective Vortex machine in The Hitchhiker's Guide to the Galaxy:

_The machine was originally created by its inventor Trin Tragula as a way to get back at his wife. She was always telling him to get a "sense of proportion," so he showed her the Vortex. Tragula was horrified to learn he had destroyed her mind, even as he proved his point that if life was going to live in such a vast Universe, one thing it could not afford to have was a sense of perspective.

The Vortex is now used as a torture and (in effect) killing device on the planet Frogstar B. The prospective victim of the TPV is placed within a small chamber wherein is displayed a model of the entire universe - together with a microscopic dot on a microscopic dot bearing the legend "you are here." The sense of perspective thereby conveyed destroys the victim's mind...._


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## THX1138 (Jul 12, 2022)

Some new images.
NASA’s James Webb Space Telescope Images Are Extraordinary


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## REBerg (Jul 13, 2022)

WOW! Only the beginning ...








						Webb Home
					

Discover the science mission of NASA’s James Webb Space Telescope (JWST), from exoplanet atmospheres to the first light in the universe—and more!




					webbtelescope.org


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## paranoid marvin (Jul 13, 2022)

Christine Wheelwright said:


> It reminds me of the Total Perspective Vortex machine in The Hitchhiker's Guide to the Galaxy:
> 
> _The machine was originally created by its inventor Trin Tragula as a way to get back at his wife. She was always telling him to get a "sense of proportion," so he showed her the Vortex. Tragula was horrified to learn he had destroyed her mind, even as he proved his point that if life was going to live in such a vast Universe, one thing it could not afford to have was a sense of perspective.
> 
> The Vortex is now used as a torture and (in effect) killing device on the planet Frogstar B. The prospective victim of the TPV is placed within a small chamber wherein is displayed a model of the entire universe - together with a microscopic dot on a microscopic dot bearing the legend "you are here." The sense of perspective thereby conveyed destroys the victim's mind...._




I felt exactly the same thing. Pictures like that really put us in our place when it comes to the human race's significance in the grand scheme on things.


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## Pyan (Jul 14, 2022)

BBC2 has a *Horizon documentary* on the inside story of the telescope at 8pm tonight.


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## mosaix (Jul 23, 2022)

Pyan said:


> BBC2 has a *Horizon documentary* on the inside story of the telescope at 8pm tonight.


Probably the best Horizon program for years.  None of the ‘scientist travelling to work’ nonsense footage that’s plagued Horizon for a decade or two.


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## Astro Pen (Jul 30, 2022)

Another reasonable length video from Bloomberg  40 minutes


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## Foxbat (Oct 21, 2022)

I never tire of looking at photos of the Pillars Of Creation (and to quote 2010…it’s full of stars!) 








						James Webb telescope spies 'Pillars of Creation'
					

One of the most famous scenes in the cosmos is viewed by the new, Nasa-led super space observatory.



					www.bbc.co.uk


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## Pyan (Oct 21, 2022)

That amazing rectangle of stars at the base of the 'third' pillar! Wow!!


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## Foxbat (Oct 21, 2022)

I amazed at the difference between Hubble and JWST photos. Just stunning


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## Pyan (Oct 21, 2022)

Not to take anything away from Hubble, though. The Pillars have merely changed from 'Magically Mysterious' to 'Majestically Glorious'..


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## Foxbat (Dec 26, 2022)

Some more stunning shots








						James Webb telescope: Amazing images show the Universe as never before
					

It's a year since the James Webb telescope launched, and we've marvelled at its pictures ever since.



					www.bbc.co.uk


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## psikeyhackr (Dec 26, 2022)

I am really out of date. I just learned that the JWST was hit by a meteor:









						Meteor impact left 'uncorrectable' damage to the Webb telescope's mirror, new report shows
					

Fortunately, engineers planned for this.




					www.livescience.com
				




Hopefully the space junk is as rare as they originally thought.


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## Vertigo (Dec 26, 2022)

psikeyhackr said:


> I am really out of date. I just learned that the JWST was hit by a meteor:
> 
> 
> 
> ...


Well at least it seems to have weathered the damage and is still performing!


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## paranoid marvin (Dec 26, 2022)

I remember I think it was a probe to Uranus (or perhaps Pluto?) where it was almost sent up without a camera to see what it looked like. The scientists etc. where much more concerned with the data than with any visual depictions of the planet, and it was an (almost) last minute decision to have a camera onboard.

I think it's images like that, and like these, that help to fund further missions and to keep it in the public conciousness.

They also make you wonder how it could be possible that things so beautiful aren't made that way to be seen.


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