Generally speaking it is about 100 times more powerful than Hubble telescope.
Astronomy & Space Exploration
- Thread starter MrMarcello
- Start date
Generally speaking it is about 100 times more powerful than Hubble telescope.
It means it can see stars going back millions & millions of years ago that no longer exist.
I assume he means 300 million light years. I think basically (it almost certainly doesn't work like this but pretend it does) imagine the telescope is capturing the image as a pixelated one. One typically sized star 300 million light years away would be approximately one pixel in size when it hits the receptor. If you're looking at something much smaller like a moon then it wouldn't be able to resolve it as "one pixel" at 300 million light years (perhaps it would only be tens of thousands of light years), and if you were looking at something much larger like a galaxy then you would be able to resolve it as "one pixel" at much further away than 300 million light years. And I could be really wrong on this one as it's pretty much just a guess, but I think you can change the focus on the telescope and look for different wavelengths to see e.g. a moon that's aligned with a planet behind which is aligned with a star behind which is aligned with a galaxy etc. If your telescope wasn't really sharp all you might be able to see would be the really bright galaxy or star but as it gets sharper and cleverer I think you can see more and more detail at different depths of field. Basically it's all a really complicated version of Father Ted saying "small....far away"!
But eventually I suspect you always get to a point so far away that the red shift in the light is too much for your telescope to see no matter how big the object is. That's why having a telescope that can see further into the infrared spectrum than Hubble is so important, it helps you see further away (=further back in time).
That's my semi-educated guess understanding of how it all works anyway. I'll bow to the greater knowledge of anyone who actually knows the answer who'd like to correct me
Last edited:
More like it can see galaxies forming 13.4 billion years ago.
Plus getting it in space is an absolutely amazing feat of engineering. Once fully deployed, the telescope will have a mirror with a diameter of 6.5m, with a sunshield behind it with a surface of 14m by 21m. All that went into space yesterday folded up in the tip of an Ariane-V rocket and will unfold automatically once the vessel has reached its destination point. It's mind-boggling how they managed that.
Also, this powerful vision won't just give us much better pictures of places in the universe, it will also allow us to look more closely into the beginnings of time, as some of the light from close to the beginning of the universe is still reaching us. Hubble isn't powerful enough to capture it, but Webb should be. (Although someone else could probably explain this better.)
Another fun fact of engineering: the mirror is so (near-)flawlessly flat that, if it would have been size the Europe, nothing would stick out more than the size of a big book.
Not sure that's what that means, because other telescopes can already resolve stars much further away than 300 million light years. The Ultra Deep Field sees stars as they were 13.2 billion years ago. I think "resolve" must mean something much more than just a pixel.
Happy to take your word for it if that's true but it's definitely the case that you can see bigger stuff from further away than you can see smaller stuff. If Hubble has seen light from galaxy/star formation from 13.2 billion years ago that absolutely wouldn't surprise me but I'd be surprised if it's seen a clear image of the star itself. As I said "imagine it as one pixel" I really don't think it actually works like that. For one thing you can stitch all kinds of images together over time and from different bits of your orbit and whatnot and build composite images. I'm sure there's all kinds of insanely clever things they can do to process the images.
That's what I thought. In the context of what he's talking about, ie a 25m version of hubble giving far greater clarity, even compared to JW which has a different purpose... but I'm so far out of my comfort zone on this that I couldn't begin to correct someone else.
Well yes, I just wanted to keep it simple
When will we get pictures?
As stated earlier in the thread - in about 6 months.
Oh I read really quick and thought it was about getting stuff ready and in place. Cool.
I know that you have a pretty good understanding of Cosmology. So would appreciate your comment.
My understanding is that the early Universe was far too hot for atoms to have formed. The plasma meant that there was just free protons and free electrons because they were moving too fast for the Strong Force to take effect.
At about 186,000 years, it became cool enough for hydrogen and helium to form. And this is referred to as Recombination.
Some time after this, the first stars and galaxies were born.
So this early period is what it is hoped that the JW Space Telescope is going to reveal?
Might be easier to understand its importance in comparison to the Hubble telescope:
- Larger and adjustable lens - collects more photons which means better resolution
- Detector in the infrared range instead of visible light - essentially looking for heat signatures instead of visible colors
- this means it can see through dust clouds
- more importantly, it can look further away (and essentially further back in time). Due to the expansion of the universe, the distant galaxies are moving away from us faster than the ones closer. This means the photons from the distant galaxies are more red-shifted such that the visible light from them would have turned into infrared by the time it reaches us.
We might see some pictures during the calibration phase of the stars it's using to calibrate itself. But new stuff will only be after the calibration is done and that is six months.
The Cosmic Background Explorer and WMAP have already looked back at that super hot early period. There's not actually much to see, just a bunch of fairly uniform protons and neutrons. JWT is designed to look after that early period when the clouds of Hydrogen and Helium began to form stars to understand how and where it happened.
Yep, that sounds about right as far as I understand it. Here's a graphic I found:
Last edited:
@nimic killing phones since 2021.
I hate modern technology if it isn't in space.
I don't think the jwst will be able to as it were lift the veil on that 380,000 year period. I posted a vid a page or so ago which made it live for me what it's going to discover. The infa red aspect is to peer through Gas clouds of Galaxies as well as being far more powerful than hubble.
In 6 months time my baby will be born, hope to have some existentially awesome pics at the time as well.
I want a kind of tracker app like I had with the iss. I want to know when the stages are happening so I can keep track. Is there one I couldn't find anything on play store
Yea was watching that earlier. We'll have to keep checking the nasa channel. What is it 2 weeks till lg2 point?
Looks like a crypto website, must be a load of meme coins already.
Thanks.
I was referring to that period you mentioned, after recombination and as the first stars and galaxies were being formed.
Yea had a look on YouTube this afternoon and it's started to do as the above article states. And roughly 1/3 the way to L2.
Scary
Scary
https://www.insider.com/china-space-race-satellite-high-resolution-san-francisco-in-seconds-2021-12
China's small Beijing-3 satellite can take high-resolution images of US cities within seconds, a speed its American counterparts can't match, scientists say
China's small Beijing-3 satellite can take high-resolution images of US cities within seconds, a speed its American counterparts can't match, scientists say
75% of the work is done. Just the mirror unfolding to do now.
Secondary mirror done (the smaller one at the front), the big one to do still. Hope all those hexagons still fit together...
Hexagons? So not pentagons, right? Because if I made them pentagon shaped they wouldn't fit together properly would they?
.......shit.
Fingers crossed but it’s looking very promising at the moment.
This isn't the right thread to troll in.
We all know the Pentagon is in America, there's no way you fit it on the James Webb Space Telescope.
Remember that satellite that crashed because someone worked in imperial while everyone else worked in metric?
Not kidding!
That was the Mars Orbiter.
That was crazy - especially that anyone working in this sort of area would use anything else than metric measurements!
Summary article in Science: https://www.science.org/content/article/stars-may-form-10-times-faster-thoughtNature Briefing said:
Full scientific article: https://www.nature.com/articles/s41586-021-04159-x
I just wish they would say somewhere what sort of timelines we are now talking about!