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For the professional (or former professional) astronomers among us, I will make my somewhat amused observation that what people are most paying attention to is not really the distinguishing features of JWST.
People seem most impressed by the apparent increase in resolution of the images, which is not from a certain point of view the hardest thing to do . HST might have done that if its instruments had been of different pixel size or imaging array size / focal length. Ok, the much larger mirror is an achievement. But anyway, the resolution of the images is often not what really is the limiting factor for photometric observations. Yes it is sharper/higher resolution, but that wasn't the key selling point.
The new thing is observations in the IR, which is somewhat a technical footnote in many gushing announcements of these images (or some discussion here too). And the general public knows little about that detail's importance, especially since the images are stylized / colored anyway to look just like RGB images that we are so familiar with. But everyone can easily appreciate a sharper image.
Anyway, still a momentous achievement. And thank god we have a scientific field where stunning images was enough to get the public to support a $10B project.
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Edit to add: I did not mean to detract from or diminish anyone's appreciation of the images and accomplishment at whatever level they are enjoyed. And of course many here are technically knowledgeable about the IR aspect. I just write to point out that for the most headline-grabbing images and newspaper writers, the sharpness of the images over the actual IR frontier is what grabs the attention.
Agreed! In the SMACS 0723 image, there is a red spiral galaxy near the top right which is effectively not present in the HST image because it was redshifted out of the spectrum. This implies it's one of the galaxies receding the fastest from us in the image right? And therefore also among the oldest and farthest away?
Also, when comparing the deep field images I don't think it can be stressed enough the difference in exposure time between HST and JWST images (Hubble had a 10x longer exposure time). Many many more distant galaxies would become visible in the JWST image with the much longer exposure time. I look forward to seeing some long-exposure deep field images from JWST!
The increased resolution is extremely important given that the diffraction threshold is function of the wavelength and the mirror diameter.
And you can clearly see that in the MIRI images at a longer wavelength that have a noticeably lower resolution compared to Nircam.
If Webb mirror was as big as Hubble the resolution would have been bad in the long wavelengths.
Hubble couldn’t have had a better resolution with better instruments, he was already limited by its aberration problem and the new instruments were designed to mitigate that problem.
Right. After the initial "wow factor" has settled down, what's been most striking to me is the level of detail that's no longer obscured by gas and dust in these nebulae due to MIRI. I know very little about the study of stellar nurseries or planetary nebulae but I've seen enough pre-JWST images of them to know that astrophysicists just got a whole lot to sink their teeth into and I look forward to seeing further developments as more data is collected and existing data is studied.
I'm impressed by the speed of the imaging. Apparently the Hubble Deep Field took over 10 days of telescope time while JWST did it in 12.5 hours.
>The new thing is observations in the IR,
Not a new thing.
Herschel space observatory operated in same location (L2-point) as JWST and it was IR telescope. https://www.google.com/search?q=Herschel+space+observatory+i...
Mirror sizes:
Hubble 4.0 m2 (43 sq ft)
Herschel 9.6 m2 (103 sq ft)
JWST 25.4 m2 (273 sq ft)
Well, also, one thing to note is that it took WEBB only hours to capture these images, while HUBBLE was aimed for days and months to capture comparable ones. It will be interesting to see the results when they have more time to capture longer sequences of light.
> HST might have done that if its instruments had been of different pixel size or imaging array size / focal length
HST is already imaging at diffraction-limited resolution (with proper post-processing). It would need a bigger mirror to get there.
If I may get political here (nothing personal / no direct reply to the parent comment):
> stunning images was enough to get the public to support a $10B project.
I don't believe public support is relevant; is there public support for the >$700B a year spent on the military?
Here's a backyard telescope versus Webb: https://twitter.com/AJamesMcCarthy/status/154694183270093209...
More comparisons on Twitter, some zoomed in:
- https://twitter.com/Batsuto_/status/1546899241880240128
- https://twitter.com/Batsuto_/status/1546900387931766784
- https://twitter.com/JBWillcox/status/1546881033597075457
- https://twitter.com/jason4short/status/1546626672488632321
I'm not a physicist, so I've only recently learned about redshift. Hubble's deep field images were very dark red/orange because further objects appear redder (into infrared) before they disappear to the observer. Webb's sensors are more red/infrared-sensitive than Hubble's, so along with extremely fine, super-cooled optics using exotic materials to align and capture every single photon, its red sensitivity allows Webb to peer deeper, further, and dimmer than we've ever been able to before.
And I've read that the "spikes" coming off the brighter stars are generally from stars in our own galaxy and they're not lens flares. They're caused by the edges of the telescope. Hubble's stars would have 4 spikes in a cross; Webb has 6 in a snowflake because of the shape of Webb's mirrors having 6 sides. Or something like that.
Question for anyone who happens to be an expert: Is there any way to quantify how much better Webb is independently of the amount of time used to take the exposures? Like, could Hubble achieve the same quality of images as Webb if it was given 100x (or whatever) more time exposure?
I'm trying to understand how much the improvement is "speed of convergence" vs. "quality of asymptotic result". (Though... is that even a valid way of trying to understand things?)
Downvote me to hell, but as a person who has zero understanding of what differentiates Hubble from Webb, the pictures alone just aren't doing it for me. I was excited to see something completely new given 30 years and 10 billion dollars and instead I feel like I'm seeing what looks like an enterprise upgrade and feel slightly disappointed.
What am I missing?
Now build a zoomable full-res version. Because I am spoiled and want the internet to do things for me.
Why is there so much more lens flare on Webb vs Hubble?
It seems to negatively degrade the photos taken much more so than Hubble.
I'm actually most looking forward to seeing a picture of our planets. I wonder what kind of resolution we'll get of Jupiter and Mars in particular.
Also curious about what the closest stars to our solar system would look like. Of course it also makes me wonder what would we be able to see given a 100x increase in aperture. Like for example if we could send up something extremely large on Starship. Would we be able to image planets in our local group? Exciting!
I read at some point that a piece of dust hit the telescope and potentially damaged it. I'm guessing that it turned out not to be a big deal or maybe they were able to work around it? Does anyone have any insight? The fact that they're releasing good pictures and not mentioning it seems like a good sign to me.
Searching for this stuff is kind of hard (information overload), so I'm wondering if anyone here has more up to date info.
This is perfect! Without this context it's hard to appreciate how much better Webb is!
Just needs to include exposure time differences and this is perfect. Glad to witness the power of this fully armed and operational battle station.
To touch the stars.
To reach a galaxy.
To dream of afar.
And in the deepest space, see our ancestry.
A question to the experts here:
What will be the most exciting things to be explored within the next months? What insight could come out of it, which open questions could be answered?
Hints to life on other planets by observing specific spectrums of specific ones? Could certain open questions about the early universe be decided? Or something else?
Aesthetically, I like the Hubble images better, they are more painterly and colorful. However there is no doubt that the JWST contains way more information and is exponentially more valuable.
Will Webb ever be used to image our own planets?
What happens when it's pointed at Mars?
Ah found answer here
https://space.stackexchange.com/questions/57492/can-james-we...
Bug report: On Firefox the difference wiper thing doesn't appear for the last image (Carina Nebula), it only shows the full Webb image.
Strange, when I compare the two images of Stephan's Quintet [1], it appears much more "progressed" in the new WEBB image [2]. But that should be impossible.
[1]: https://en.wikipedia.org/wiki/File:Stephan%27s_Quintet_Hubbl... [2]: https://johnedchristensen.github.io/WebbCompare/img/Stephans...
Hmm, for some reason I prefer Hubble's image of Stephan's Quintet over JWST's. Though, that is purely from an aesthetic perspective. I am sure JWST's is much more impressive from a scientific standpoint.
Does someone have any intuitive explanation on why Hubble images for bright stars seem to have a cross-shaped lens-flare effect, while for JWT it's got six spikes?
It might be because of a different post-processing algorithm, or some phi-related magic, just curious a bit.
> This makes the Hubble telescope even more impressive in my eyes. Built 50 years ago with presumably 60 year old tech.
> > Hubble telescope was funded and built in the 1970s by the United States space agency NASA with contributions from the European Space Agency. Its intended launch was 1983, but the project was beset by technical delays, budget problems, and the 1986 Challenger disaster. Hubble was finally launched in 1990.
I commented on this other thread: https://news.ycombinator.com/item?id=32074242
The sliders break when page zoom is anything other than 100% :/
I’m curious what’s going on in the upper left area of the Carina Nebula image. The dust can’t have actually cleared out that much since the Hubble shot was taken, could it?
Considering these are just the initial "test" images there is going to be some amazing stuff to come over the years. Can't wait.
Advantages of IR incredibly apparent in the last pic.
Very nicely done!
I do like that this is generating interest and optimism for science again, yet I have yet to hear a good answer on what new insight we can expect from the lifetime of the telescope. Does someone have a good list of questions we're hoping to get better answers for?
At this point I like it even for just brightening the news cycle anyway.
It's a bit ironic that to me, the layman, Hubble's space images have been so ubiquitous that Webb looks kind of... posterized. For example, in that last comparison of the Carina Nebula, Hubble has that ethereal quality that so many space pictures do, whereas Webb's crispness reminds me almost of a drawing.
So, I have a few questions.
1. Can the telescope be pointed in any direction? (of course, orthogonal to the suns rays, I understand the need to cool it down).
2. If it can be pointed, I am assuming some boosters would be used to pivot it. How long do these last?
3. Is there any info on the orbit? Can the orbit degrade?
4. All the fluid / gas required to correct / point, can it be refilled?
Very cool to see several galaxies that were entirely invisible to Hubble due to high redshift show up brightly to JWST.
The new scope appears to be capable of wonderful images, and no doubt many new discoveries.
Too bad, then, about the crappy colorizing/outlining for the 'so pretty' crowd. I await the site that simply shows (frequency-shifted) images. Any colorizing should have a 'legend' describing its purpose.
The Carina Nebula is the most amazing photo. The level of detail now shown by JWST is breathtaking.
My God, it's full of stars!
Interesting that while they're certainly more detailed they also look "flatter" than the Hubble images. Is that due to differences in hardware or different choices in post-processing?
How much and what type post processing are appled to these type of images?
old and new images already looked highly processed, that photoshop look - which i think some of us got a little jaded on maybe.
what's more interesting to me is what we can learn about exoplanets from this mission
https://www.nasa.gov/image-feature/goddard/2022/nasa-s-webb-...
Are the four vs six point starbursts an artifact of the different lens / mirror designs? The Webb telescope has hexagonal mirrors, but not sure about Hubble.
Did anybody make a comparison for rough estimation on the number of galaxies in the observable universe based on hubble vs webb?
Thank you so much!!! I really wanted to see the difference side by side and this was an even better presentation. Really cool!
These need to be adjusted for brightness... The Hubble ones are a lot darker which make things harder to spot.
Is it absurd to think that maybe the Carina Nebula's shape has visibly shifted a bit since the last photo?
I love this. But the Carina Nebula doesn't work on Firefox for Android. It just displays the JWST image.
Amazing! Would be interesting to also compare with earth-bound telescopes, to really appreciate the progress.