21 ms·

Compare Webb's Images to Hubble

1636 points by hexomancer 4y ago

somenewaccount1 4y ago
Thank you so much!!! I really wanted to see the difference side by side and this was an even better presentation. Really cool!
- hexomancer 4y ago
  Just to be clear I did not create this website, I just saw it on reddit. All credits to the original author: https://www.reddit.com/r/woahdude/comments/vxeeqo/i_made_a_tool_to_compare_webbs_new_images_to/ https://www.reddit.com/r/woahdude/comments/vxeeqo/i_made_a_t...
ijidak 4y ago
This is perfect! Without this context it's hard to appreciate how much better Webb is!
mholt 4y ago
Here's a backyard telescope versus Webb: https://twitter.com/AJamesMcCarthy/status/1546941832700932096 https://twitter.com/AJamesMcCarthy/status/154694183270093209... More comparisons on Twitter, some zoomed in: - https://twitter.com/Batsuto_/status/1546899241880240128 https://twitter.com/Batsuto_/status/1546899241880240128 - https://twitter.com/Batsuto_/status/1546900387931766784 https://twitter.com/Batsuto_/status/1546900387931766784 - https://twitter.com/JBWillcox/status/1546881033597075457 https://twitter.com/JBWillcox/status/1546881033597075457 - https://twitter.com/jason4short/status/1546626672488632321 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.
- kadoban 4y ago
  They're not lens flares, but they're still an artifact of the system, which is probably what most people mean by "lens flare" anyway, due to lack of a better common term.
  - JacobThreeThree 4y ago
    According to the Wikipedia definition, I'd say that Webb's artifacts could be classified as "lens flares". >This happens through light scattered by the imaging mechanism itself, for example through internal reflection and forward scatter from material imperfections in the lens. Lenses with large numbers of elements such as zooms tend to have more lens flare, as they contain a relatively large number of interfaces at which internal scattering may occur. https://en.wikipedia.org/wiki/Lens_flare https://en.wikipedia.org/wiki/Lens_flare
    - Cogito 4y ago
      Diffraction spikes are caused before the lens gets involved; improving the lenses cannot remove the spikes (though there may be structures causing diffraction spikes in-between lenses). The spikes from JWST are primarily caused by the edges of the mirrors and the three support struts. There likely is some amount of lens flare (though I don't know if it is significant, the optics are Very Good), but the dominant artefact is the diffraction spikes.
      - JacobThreeThree 4y ago
        >The spikes from JWST are primarily caused by the edges of the mirrors and the three support struts. That sounds to me like "light scattered by the imaging mechanism".
  - m463 4y ago
    Actually I would say the effect mimics a "cross filter" / "star filter" special effect. https://en.wikipedia.org/wiki/Photographic_filter#Cross_screen https://en.wikipedia.org/wiki/Photographic_filter#Cross_scre...
thatswrong0 4y ago
Just needs to include exposure time differences and this is perfect. Glad to witness the power of this fully armed and operational battle station.
- laserbeam 4y ago
  It's my understanding that Webb used much shorter exposure times than Hubble, correct?
  - tambourine_man 4y ago
    Yes, hours vs days, which makes them a lot more impressive if you know a bit about photography. I wanna see what this thing is able to do with a 10 days exposure. Let it loose.
    - dylan604 4y ago
      >I wanna see what this thing is able to do with a 10 days exposure. Ever seen a solid white square? =) As with all things, it totally depends on what's being imaged. Exposing the Orion Nebula for 10 days would result in a totally over exposed image looking like a solid white square.
      - tambourine_man 4y ago
        I trust astronomers to know how to set the exposure. I want the Webb focusing 10 days on a patch that looks pitch black on Hubble’s 10 days deep field
  - akira2501 4y ago
    Exposure time on Webb is complicated. The sensors are different, the sampling techniques are different, and you can get the on board systems to do integration within sets of exposures for you. https://jwst-docs.stsci.edu/understanding-exposure-times https://jwst-docs.stsci.edu/understanding-exposure-times
wanderingstan 4y ago
Amazing! Would be interesting to also compare with earth-bound telescopes, to really appreciate the progress.
prohobo 4y ago
Is it absurd to think that maybe the Carina Nebula's shape has visibly shifted a bit since the last photo?
baltimore 4y ago
Now build a zoomable full-res version. Because I am spoiled and want the internet to do things for me.
- nabakin 4y ago
  I made a full-res version for the Carina Nebula. Not sure how to make it zoomable on desktop (it's zoomable on mobile). https://hubblevwebb.tiiny.site/ https://hubblevwebb.tiiny.site/
- mtlmtlmtlmtl 4y ago
  Not a UI or web guy scaling the slider with zoom might do the trick?
- yread 4y ago
  ESA got your back: quintet: https://esawebb.org/images/weic2208a/zoomable/ https://esawebb.org/images/weic2208a/zoomable/ https://esawebb.org/images/weic2208b/zoomable/ https://esawebb.org/images/weic2208b/zoomable/ carina: https://esawebb.org/images/weic2205a/zoomable/ https://esawebb.org/images/weic2205a/zoomable/ https://esawebb.org/images/weic2205b/zoomable/ https://esawebb.org/images/weic2205b/zoomable/ Southern ring https://esawebb.org/images/weic2207a/zoomable/ https://esawebb.org/images/weic2207a/zoomable/ https://esawebb.org/images/weic2207b/zoomable/ https://esawebb.org/images/weic2207b/zoomable/ https://esawebb.org/images/weic2207c/zoomable/ https://esawebb.org/images/weic2207c/zoomable/ Deep field https://esawebb.org/images/weic2209a/zoomable/ https://esawebb.org/images/weic2209a/zoomable/ https://esawebb.org/images/weic2209b/zoomable/ https://esawebb.org/images/weic2209b/zoomable/
  - mrleinad 4y ago
    Well, I found my next set of ultrawide wallpapers for my 49" monitor :) Thanks!
- TestSubject1498 4y ago
  I made this site an I released update to allow zoom! Let me know what you think!
_benj 4y ago
just WOW! I always feel so tiny when considering the absurd dimensions of space brought shockingly vivid with this images!
deleted 4y ago
[deleted]
nooyurrsdey 4y ago
This is a wonderful way to visualize side by side images like this. Great work, it feels smooth and intuitive.
mtlmtlmtlmtl 4y ago
I love this. But the Carina Nebula doesn't work on Firefox for Android. It just displays the JWST image.
- red_trumpet 4y ago
  Changing the orientation of my phone from portrait to landscape while on the site somewhat solved this.
- yellowapple 4y ago
  For me it shows the top half of the Hubble version, but not the bottom.
  - wlesieutre 4y ago
    That's the extent of the Hubble original https://hubblesite.org/contents/media/images/2008/34/2405-Image.html?keyword=3324&filterUUID=6b40edb4-2a47-4f89-8047-2fe9359344f3 https://hubblesite.org/contents/media/images/2008/34/2405-Im...
    - mtlmtlmtlmtl 4y ago
      That makes sense then. I have two suggestions if the person who made this is reading: maybe fill out the hubble image with black so it can line up with the JWST image, might make the interface less janky? Or if someone knows of a larger imagine from another telescope(Spitzer?) That could be a more interesting comparison for that particular observation.
fleddr 4y ago
Pretty expensive Insta filter.
matesz 4y ago
Did anybody make a comparison for rough estimation on the number of galaxies in the observable universe based on hubble vs webb?
jauntbox 4y ago
Very cool to see several galaxies that were entirely invisible to Hubble due to high redshift show up brightly to JWST.
systemvoltage 4y ago
> 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 https://news.ycombinator.com/item?id=32074242
jcims 4y ago
Advantages of IR incredibly apparent in the last pic. Very nicely done!
dynm 4y ago
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?)
- dylan604 4y ago
  No, expsoure time is not enough. Resolution is a factor of the size of the primary mirror. Exposure time just allows capture of photons at that resolution. With the JWST primary mirror dwarfing the Hubble's, then it will always have better imagery.
  - 0xfaded 4y ago
    Wavelength is also a factor. Huygens optics has a great video on this. tldr; angular resolution is about the same as the Hubble. https://youtu.be/gOpbXBppUEU https://youtu.be/gOpbXBppUEU
- red_trumpet 4y ago
  I'm no expert either, but I imagine that high exposure times come with more motion blur. So just cranking up exposure time does not necessarily result in better pictures.
  - IshKebab 4y ago
    Motion of what?
    - dontlistentome 4y ago
      everything everywhere all at once
    - spookthesunset 4y ago
protoster 4y ago
Bug report: On Firefox the difference wiper thing doesn't appear for the last image (Carina Nebula), it only shows the full Webb image.
- weaksauce 4y ago
  funny enough that one didn't work on chrome but worked in firefox nightly albeit a distorted version that only showed the top left corner of it... I'm not sure hubble shot the full version? https://i.imgur.com/oBK3sWE.png https://i.imgur.com/oBK3sWE.png
  - ask_b123 4y ago
    I'm seeing the same and I assumed that Hubble hadn't shot the full version.
- nathancahill 4y ago
  Working on latest FF on Mac. The Hubble image is just smaller.
- mastazi 4y ago
  on Brave, instead it's the polar opposite, only the Carina Nebula works Edit it could be because of my default zoom level https://news.ycombinator.com/item?id=32076048 https://news.ycombinator.com/item?id=32076048
bandyaboot 4y ago
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?
- CitizenKane 4y ago
  I believe the Hubble shot is more in the visible spectrum whereas the JWST images are in infrared so there are structures in each shot that don't necessarily show up in the analogous image.
- treesknees 4y ago
  I'm not an expert, but from what I came across online earlier, the Hubble telescope sees more of the visible/UV spectrum than the Webb telescope. So it may just be a difference in what's captured. This site has a diagram of the spectrum that shows which portions are covered by each telescope, as well as some video clips comparing photos captured by Hubble and Webb. The first video of the Lagoon Nebula (M8) demonstrates what I'm saying pretty well. https://webbtelescope.org/webb-science/the-observatory/infrared-astronomy https://webbtelescope.org/webb-science/the-observatory/infra...
- pkaye 4y ago
  With infrared you can see through the dust.
  - xenadu02 4y ago
    Indeed - that's one of the primary reasons to build the JWT: Dust and gas blocks our view in various cases so we want to take images in wavelengths that are more transparent to that debris.
- dylan604 4y ago
  Lots of visible light is reflected in the Hubble image from the dust causing it to look like it does. As others have said, the JWST does not suffer from that as it "sees" past those frequencies revealing new details instead.
rnmp 4y ago
It’s as if they remastered an old video game. So much more detail!
alberth 4y ago
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.
- Dave_Rosenthal 4y ago
  The segmented design of the mirror creates diffraction effects vs. Hubble's single mirror.
- kristofferR 4y ago
  This is a great explanation: https://bigthink.com/starts-with-a-bang/james-webb-spikes/ https://bigthink.com/starts-with-a-bang/james-webb-spikes/
  - libraryatnight 4y ago
    This is interesting, thank you - going to pass this along to friends who were curious and got less informative answers :)
masterspy7 4y ago
Not trying to underscore this incredible achievement, but I'm curious if we could use AI techniques to upscale the Hubble images to achieve similar results as the Webb telescope. Has this been tried before?
- deleted 4y ago
  [deleted]
- detaro 4y ago
  AI upscaling works if you want a prettier picture, but not if you want to actually know more. AI can't magically conjure information that isn't there, so if you upscale it has to invent details to fill in. Which is fine for some use cases, but not for science or truth-finding.
- Kelm 4y ago
  Sure you could try, but without getting real higher fidelity photos you’d never know how realistic the synthetic images are.
- wetpaws 4y ago
  No
- lynguist 4y ago
  It’s a valid thought, but it would really be like trying to take pictures of the sky from underwater and using AI to make it look like it was taken from out of water. This means: the AI has to predict what it is supposed to look like and for that we would need out of water pictures as reference in the first place which we didn’t so far! And then: even if we have these new out of water pictures as reference, the AI generated ones would still not show what is real, but instead a fiction. The fiction can look believable but it cannot be studied to derive facts from it. It’s like trying to study an AI generated language. This sounds like my friend who literally believes that buses will go extinct within 3-5 years as every vehicle will self drive. It’s not thought all the way through.
  - Balgair 4y ago
angryGhost 4y ago
born too early...
- echelon 4y ago
  For the machines that will replace us.
supernova87a 4y ago
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. ** 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.
- AQXt 4y ago
  > especially since the images are stylized / colored anyway The thing that I don't like about the new images is the abuse of star flare effect. The colors are okay, but the flares... that's simply too much.
  - tiagod 4y ago
    I don't think that's on purpose
  - ygra 4y ago
    It's not an effect. It's a diffraction artifact that's a consequence of the telescope construction. Explained here for example: https://bigthink.com/starts-with-a-bang/james-webb-spikes/ https://bigthink.com/starts-with-a-bang/james-webb-spikes/
woevdbz 4y ago
It's striking how much more flamelike the structures appear to be, with the added resolution
avelis 4y ago
To touch the stars. To reach a galaxy. To dream of afar. And in the deepest space, see our ancestry.
- throwaway4837 4y ago
  It's hard to look at the Webb images without thinking that there must be life and technology out somewhere else in the stars.
  - dylan604 4y ago
    Why does that only come from Webb images? You weren't getting that same sensation looking at the Hubble images before? If that's true, then welcome to the club! It took you a bit longer, but we're happy you're here now. ;P
    - throwaway4837 4y ago
      > Why does that only come from Webb images? Re-read comment.
      - dylan604 4y ago
        "It's hard to look at the Webb images without thinking..." What am I missing?
        scrollaway 4y ago
        A charitable interpretation. You're making the assumption the poster meant they didn't have this feeling before. They might just be repeating that, once again, it's difficult to do this with Webb. Hubble is irrelevant. Anything else is irrelevant. They're talking about the pictures here in front of us.
        dylan604 4y ago
        cheap shot? I was absolutely agreeing with the sentiment. I clearly asked if the feeling was there before as well or if it was just from the new images. Thanks for your charity though
acqbu 4y ago
Hubble = iPhone 4S; Webb = Galaxy S22 Ultra
UberFly 4y ago
Considering these are just the initial "test" images there is going to be some amazing stuff to come over the years. Can't wait.
boomskats 4y ago
The sliders break when page zoom is anything other than 100% :/
bastardoperator 4y ago
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?
- Mangalor 4y ago
  These are just the first few images. Give it time.
  - SiempreViernes 4y ago
    That's somewhat fair, but Hubble and JWST have fundamentally pretty similar resolutions so JWST will never get hugely better. What JWST can do is show new things that have never been seen before, but obviously it's a bit hard to schedule that sort of photos.
- stevage 4y ago
  With respect, the goal of a major scientific project is not to impress the layperson with pretty pictures.
  - kmano8 4y ago
    Though of course the pretty pictures really help with increasing the appetite from the public for spending on projects like this.. and capturing people's imaginations is a necessary part of the long game.
- echelon 4y ago
  I can understand this sentiment, but I'm excited by the results we won't see: chemical spectra. Getting readings from the atmospheres of exoplanets will give us an idea of what population and percentages could harbor life. We may even get a whiff of some tell tale signs of industry, and that would change life on earth forever.
- 4y ago
8bitsrule 4y ago
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.
hparadiz 4y ago
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!
- svachalek 4y ago
  We've got very good pictures of our own planets thanks to probes that did flybys. Maybe I'm way off but I'm pretty sure JWST won't be able to beat those. I also wonder if it can even handle that much light, I know it can't look at the moon or it will burn out.
  - hparadiz 4y ago
    Oh for sure it won't. I'm more interested in that as a tech demo.
- Balgair 4y ago
  Imaging Phattie/IX would also be pretty cool. It's been a while since we've discovered a real big-boy planet. https://en.wikipedia.org/wiki/Planet_Nine https://en.wikipedia.org/wiki/Planet_Nine
irrational 4y ago
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.
eevilspock 4y ago
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.
temptemptemp111 4y ago
SCAQTony 4y ago
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.
- codq 4y ago
  It's kinda like listening to music on vinyl vs. digital. High quality digital is clearly superior sonically, but vinyl has a dullness around the edges that is so aesthetically pleasing. I agree that the Hubble images are just pleasant to look at, warm and wonderful.
- tmm84 4y ago
  I'm glad someone here said this about them. I grew up seeing Hubble style images (non-IR) so I get the warm fuzziness they have. For me the one thing that gets me are the big shiny stars that seem to have big streaks going everywhere. They feel like lens flare in the photos.
- izacus 4y ago
  Ummm, pretty much all of those images are artificially colored so your comment basically just judges the person postprocessing the images and applying colors for detected wavelengths.
WalterBright 4y ago
My God, it's full of stars!
Unklejoe 4y ago
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.
- dtgriscom 4y ago
  https://blogs.nasa.gov/webb/2022/06/08/webb-engineered-to-endure-micrometeoroid-impacts/ https://blogs.nasa.gov/webb/2022/06/08/webb-engineered-to-en... Summary: they can see it in the data, but events such as this were expected and part of the lifetime of the telescope.
kumarvvr 4y ago
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?
- Bjartr 4y ago
  For 2, JWST uses reaction wheels to manage it's orientation. These are just heavy wheels it spins faster or slower to change it's own angular momentum. https://jwst-docs.stsci.edu/jwst-observatory-hardware/jwst-momentum-management https://jwst-docs.stsci.edu/jwst-observatory-hardware/jwst-m...
- Laremere 4y ago
  1. It can be pointed at any direction, just not at any time. It actually can't look directly away from the sun either, just to the sides. See https://jwst-docs.stsci.edu/jwst-observatory-characteristics/jwst-observatory-coordinate-system-and-field-of-regard/jwst-target-viewing-constraints https://jwst-docs.stsci.edu/jwst-observatory-characteristics... 2. Basically any satellite in use today uses spinning masses which it can speed up or down to change the direction it's looking. Angular momentum is conserved, but direction pointing isn't. Eventually due to uneven forces (eg, from the sun), these reaction wheels become "saturated" and some propellant is used slow the wheels down. Current estimates put the fuel running out in more than a decade. 3. It's an orbit in L2, past the Earth from the Sun's view. This orbit is unstable, and some of the fuel will also be used to maintain this orbit. 4. There is no refilling mechanism built in. It's likely once the propellant is out the mission will be done. There is the possibility of another spacecraft grabbing onto James Webb and pushing it for station keeping, but it wouldn't be able to refill it. One major innovation with the James Webb though is that it's refrigerator is closed loop, as otherwise running out of coolant would be the mission limiting factor.
tonymet 4y ago
what’s the practical application ?
- Balgair 4y ago
  Of astronomy?
  - tonymet 4y ago
    of the James Webb Telescope
    - Balgair 4y ago
      I mean, it's pretty much asking what the practical applications of astronomy are. It's the marquee instrument now.
      - tonymet 4y ago
        feel free to share your thoughts
        Balgair 4y ago
        seems pretty cool, lots of tech n stuff. How about you?
        tonymet 4y ago
        pretty illustrations , not much more
        Balgair 4y ago
        yeah, like who cares about heliophysics
ck2 4y ago
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-webb-take-pictures-of-our-solar-system-in-what-ways-will-they-differ https://space.stackexchange.com/questions/57492/can-james-we...
FloatArtifact 4y ago
How much and what type post processing are appled to these type of images?
- mordae 4y ago
  Most importantly the light frequencies have been mapped to visible spectrum.
TeeMassive 4y ago
Notice how the Southern Ring Nebula has expanded
deepzn 4y ago
The Carina Nebula is the most amazing photo. The level of detail now shown by JWST is breathtaking.
- nabakin 4y ago
  I think so too. I even made another comparison website for it because OP's website doesn't use the full resolution images. Each image is about 50 MB so it will take awhile for it to load. https://hubblevwebb.tiiny.site https://hubblevwebb.tiiny.site
Helmut10001 4y ago
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_Hubble_2009.full_denoise.jpg https://en.wikipedia.org/wiki/File:Stephan%27s_Quintet_Hubbl... [2]: https://johnedchristensen.github.io/WebbCompare/img/Stephans_Quintent_Webb.jpg https://johnedchristensen.github.io/WebbCompare/img/Stephans...
- dan_mctree 4y ago
  Overlaying them, it seems the JWST images have brighter galaxy edges and gas. This makes the galaxies look bigger, which in turn could make it appear as if the galaxies are closer together. Is that what you mean with 'progressed'?
  - Helmut10001 4y ago
    Yes, I think you're right - also, the linked HUBBLE image from wikipedia is rotated a bit, which increases the effect that two of the 5 galaxies appear to be closer together in the WEBB image.
anigbrowl 4y ago
I'm slightly surprised they haven't gotten rid of the stellated hexagon artifacts with software.
- mordae 4y ago
  And replace them with what?
  - anigbrowl 4y ago
    Nothing, that's kinda the point. I'm not talking about just deleting the pixels. If you know your measurement instrument introduces artifacts, you just move it around or use some ground-truth image until you map the artifacts and then subtract them out by convolution.
justanotherme 4y ago
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?
- sandgiant 4y ago
  What you find most exciting is a subjective thing. I don't have a clear answer, but you can browse through the list of accepted proposals in cycle 1 and decide for yourself: https://www.stsci.edu/jwst/science-execution/approved-programs https://www.stsci.edu/jwst/science-execution/approved-progra....
5350-uiop-1130 4y ago
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-reveals-steamy-atmosphere-of-distant-planet-in-detail https://www.nasa.gov/image-feature/goddard/2022/nasa-s-webb-...
- ygra 4y ago
  Isn't that look mostly a mapping of the observed wavelengths into the visible spectrum? I think at least for some of those images the different colors correspond to different chemical elements, which makes for pretty images _and_ some extra data that's interesting. For purposes of comparison with Hubble images it would also make sense to process them in the same way. But apart from that, there's the raw data, which is surely somewhere in the public domain, but that's way less useful in communicating those achievements to the public.
d--b 4y ago
These need to be adjusted for brightness... The Hubble ones are a lot darker which make things harder to spot.
- dtgriscom 4y ago
  I just filed an issue on the project. (Gotta look that gift horse in the mouth...)
sharmin123 4y ago
causi 4y ago
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?
smohare 4y ago
Damn near unusable of mobile. Cool.
mihaic 4y ago
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.
mihaic 4y ago
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.
- cainxinth 4y ago
  I believe the six spikes from JWST are because of its hexagonal mirror segments.
  - FourHand451 4y ago
    This was my guess as well, but if it's correct, I don't understand why the Hubble images show 4 spikes. I thought Hubble's main mirror was circular, not a square.
    - cainxinth 4y ago
      As usual, wiki has the answer: https://en.wikipedia.org/wiki/Diffraction_spike https://en.wikipedia.org/wiki/Diffraction_spike >"...four spider vanes supporting the secondary mirror. These cause the four spike diffraction pattern commonly seen in astronomical images."
suddenexample 4y ago
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.
jhoechtl 4y ago
The post-processing in the webb images is hilarious. Marketing at its best.

1636 points by hexomancer 4y ago

Thank you so much!!! I really wanted to see the difference side by side and this was an even better presentation. Really cool!

hexomancer 4y ago
Just to be clear I did not create this website, I just saw it on reddit. All credits to the original author: https://www.reddit.com/r/woahdude/comments/vxeeqo/i_made_a_tool_to_compare_webbs_new_images_to/ https://www.reddit.com/r/woahdude/comments/vxeeqo/i_made_a_t...

ijidak 4y ago

This is perfect! Without this context it's hard to appreciate how much better Webb is!

mholt 4y ago

Here's a backyard telescope versus Webb: https://twitter.com/AJamesMcCarthy/status/1546941832700932096 https://twitter.com/AJamesMcCarthy/status/154694183270093209... More comparisons on Twitter, some zoomed in: - https://twitter.com/Batsuto_/status/1546899241880240128 https://twitter.com/Batsuto_/status/1546899241880240128 - https://twitter.com/Batsuto_/status/1546900387931766784 https://twitter.com/Batsuto_/status/1546900387931766784 - https://twitter.com/JBWillcox/status/1546881033597075457 https://twitter.com/JBWillcox/status/1546881033597075457 - https://twitter.com/jason4short/status/1546626672488632321 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.

kadoban 4y ago
They're not lens flares, but they're still an artifact of the system, which is probably what most people mean by "lens flare" anyway, due to lack of a better common term.
- JacobThreeThree 4y ago
  According to the Wikipedia definition, I'd say that Webb's artifacts could be classified as "lens flares". >This happens through light scattered by the imaging mechanism itself, for example through internal reflection and forward scatter from material imperfections in the lens. Lenses with large numbers of elements such as zooms tend to have more lens flare, as they contain a relatively large number of interfaces at which internal scattering may occur. https://en.wikipedia.org/wiki/Lens_flare https://en.wikipedia.org/wiki/Lens_flare
  - Cogito 4y ago
    Diffraction spikes are caused before the lens gets involved; improving the lenses cannot remove the spikes (though there may be structures causing diffraction spikes in-between lenses). The spikes from JWST are primarily caused by the edges of the mirrors and the three support struts. There likely is some amount of lens flare (though I don't know if it is significant, the optics are Very Good), but the dominant artefact is the diffraction spikes.
    - JacobThreeThree 4y ago
      >The spikes from JWST are primarily caused by the edges of the mirrors and the three support struts. That sounds to me like "light scattered by the imaging mechanism".
- m463 4y ago
  Actually I would say the effect mimics a "cross filter" / "star filter" special effect. https://en.wikipedia.org/wiki/Photographic_filter#Cross_screen https://en.wikipedia.org/wiki/Photographic_filter#Cross_scre...

thatswrong0 4y ago

Just needs to include exposure time differences and this is perfect. Glad to witness the power of this fully armed and operational battle station.

laserbeam 4y ago
It's my understanding that Webb used much shorter exposure times than Hubble, correct?
- tambourine_man 4y ago
  Yes, hours vs days, which makes them a lot more impressive if you know a bit about photography. I wanna see what this thing is able to do with a 10 days exposure. Let it loose.
  - dylan604 4y ago
    >I wanna see what this thing is able to do with a 10 days exposure. Ever seen a solid white square? =) As with all things, it totally depends on what's being imaged. Exposing the Orion Nebula for 10 days would result in a totally over exposed image looking like a solid white square.
    - tambourine_man 4y ago
      I trust astronomers to know how to set the exposure. I want the Webb focusing 10 days on a patch that looks pitch black on Hubble’s 10 days deep field
- akira2501 4y ago
  Exposure time on Webb is complicated. The sensors are different, the sampling techniques are different, and you can get the on board systems to do integration within sets of exposures for you. https://jwst-docs.stsci.edu/understanding-exposure-times https://jwst-docs.stsci.edu/understanding-exposure-times

wanderingstan 4y ago

Amazing! Would be interesting to also compare with earth-bound telescopes, to really appreciate the progress.

prohobo 4y ago

Is it absurd to think that maybe the Carina Nebula's shape has visibly shifted a bit since the last photo?

baltimore 4y ago

Now build a zoomable full-res version. Because I am spoiled and want the internet to do things for me.

nabakin 4y ago
I made a full-res version for the Carina Nebula. Not sure how to make it zoomable on desktop (it's zoomable on mobile). https://hubblevwebb.tiiny.site/ https://hubblevwebb.tiiny.site/
mtlmtlmtlmtl 4y ago
Not a UI or web guy scaling the slider with zoom might do the trick?
yread 4y ago
ESA got your back: quintet: https://esawebb.org/images/weic2208a/zoomable/ https://esawebb.org/images/weic2208a/zoomable/ https://esawebb.org/images/weic2208b/zoomable/ https://esawebb.org/images/weic2208b/zoomable/ carina: https://esawebb.org/images/weic2205a/zoomable/ https://esawebb.org/images/weic2205a/zoomable/ https://esawebb.org/images/weic2205b/zoomable/ https://esawebb.org/images/weic2205b/zoomable/ Southern ring https://esawebb.org/images/weic2207a/zoomable/ https://esawebb.org/images/weic2207a/zoomable/ https://esawebb.org/images/weic2207b/zoomable/ https://esawebb.org/images/weic2207b/zoomable/ https://esawebb.org/images/weic2207c/zoomable/ https://esawebb.org/images/weic2207c/zoomable/ Deep field https://esawebb.org/images/weic2209a/zoomable/ https://esawebb.org/images/weic2209a/zoomable/ https://esawebb.org/images/weic2209b/zoomable/ https://esawebb.org/images/weic2209b/zoomable/
- mrleinad 4y ago
  Well, I found my next set of ultrawide wallpapers for my 49" monitor :) Thanks!
TestSubject1498 4y ago
I made this site an I released update to allow zoom! Let me know what you think!

_benj 4y ago

just WOW! I always feel so tiny when considering the absurd dimensions of space brought shockingly vivid with this images!

deleted 4y ago

[deleted]

nooyurrsdey 4y ago

This is a wonderful way to visualize side by side images like this. Great work, it feels smooth and intuitive.

mtlmtlmtlmtl 4y ago

I love this. But the Carina Nebula doesn't work on Firefox for Android. It just displays the JWST image.

red_trumpet 4y ago
Changing the orientation of my phone from portrait to landscape while on the site somewhat solved this.
yellowapple 4y ago
For me it shows the top half of the Hubble version, but not the bottom.
- wlesieutre 4y ago
  That's the extent of the Hubble original https://hubblesite.org/contents/media/images/2008/34/2405-Image.html?keyword=3324&filterUUID=6b40edb4-2a47-4f89-8047-2fe9359344f3 https://hubblesite.org/contents/media/images/2008/34/2405-Im...
  - mtlmtlmtlmtl 4y ago
    That makes sense then. I have two suggestions if the person who made this is reading: maybe fill out the hubble image with black so it can line up with the JWST image, might make the interface less janky? Or if someone knows of a larger imagine from another telescope(Spitzer?) That could be a more interesting comparison for that particular observation.

fleddr 4y ago

Pretty expensive Insta filter.

matesz 4y ago

Did anybody make a comparison for rough estimation on the number of galaxies in the observable universe based on hubble vs webb?

jauntbox 4y ago

Very cool to see several galaxies that were entirely invisible to Hubble due to high redshift show up brightly to JWST.

systemvoltage 4y ago

> 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 https://news.ycombinator.com/item?id=32074242

jcims 4y ago

Advantages of IR incredibly apparent in the last pic. Very nicely done!

dynm 4y ago

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?)

dylan604 4y ago
No, expsoure time is not enough. Resolution is a factor of the size of the primary mirror. Exposure time just allows capture of photons at that resolution. With the JWST primary mirror dwarfing the Hubble's, then it will always have better imagery.
- 0xfaded 4y ago
  Wavelength is also a factor. Huygens optics has a great video on this. tldr; angular resolution is about the same as the Hubble. https://youtu.be/gOpbXBppUEU https://youtu.be/gOpbXBppUEU
red_trumpet 4y ago
I'm no expert either, but I imagine that high exposure times come with more motion blur. So just cranking up exposure time does not necessarily result in better pictures.
- IshKebab 4y ago
  Motion of what?
  - dontlistentome 4y ago
    everything everywhere all at once
  - spookthesunset 4y ago

protoster 4y ago

Bug report: On Firefox the difference wiper thing doesn't appear for the last image (Carina Nebula), it only shows the full Webb image.

weaksauce 4y ago
funny enough that one didn't work on chrome but worked in firefox nightly albeit a distorted version that only showed the top left corner of it... I'm not sure hubble shot the full version? https://i.imgur.com/oBK3sWE.png https://i.imgur.com/oBK3sWE.png
- ask_b123 4y ago
  I'm seeing the same and I assumed that Hubble hadn't shot the full version.
nathancahill 4y ago
Working on latest FF on Mac. The Hubble image is just smaller.
mastazi 4y ago
on Brave, instead it's the polar opposite, only the Carina Nebula works Edit it could be because of my default zoom level https://news.ycombinator.com/item?id=32076048 https://news.ycombinator.com/item?id=32076048

bandyaboot 4y ago

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?

CitizenKane 4y ago
I believe the Hubble shot is more in the visible spectrum whereas the JWST images are in infrared so there are structures in each shot that don't necessarily show up in the analogous image.
treesknees 4y ago
I'm not an expert, but from what I came across online earlier, the Hubble telescope sees more of the visible/UV spectrum than the Webb telescope. So it may just be a difference in what's captured. This site has a diagram of the spectrum that shows which portions are covered by each telescope, as well as some video clips comparing photos captured by Hubble and Webb. The first video of the Lagoon Nebula (M8) demonstrates what I'm saying pretty well. https://webbtelescope.org/webb-science/the-observatory/infrared-astronomy https://webbtelescope.org/webb-science/the-observatory/infra...
pkaye 4y ago
With infrared you can see through the dust.
- xenadu02 4y ago
  Indeed - that's one of the primary reasons to build the JWT: Dust and gas blocks our view in various cases so we want to take images in wavelengths that are more transparent to that debris.
dylan604 4y ago
Lots of visible light is reflected in the Hubble image from the dust causing it to look like it does. As others have said, the JWST does not suffer from that as it "sees" past those frequencies revealing new details instead.

rnmp 4y ago

It’s as if they remastered an old video game. So much more detail!

alberth 4y ago

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.

Dave_Rosenthal 4y ago
The segmented design of the mirror creates diffraction effects vs. Hubble's single mirror.
kristofferR 4y ago
This is a great explanation: https://bigthink.com/starts-with-a-bang/james-webb-spikes/ https://bigthink.com/starts-with-a-bang/james-webb-spikes/
- libraryatnight 4y ago
  This is interesting, thank you - going to pass this along to friends who were curious and got less informative answers :)

masterspy7 4y ago

Not trying to underscore this incredible achievement, but I'm curious if we could use AI techniques to upscale the Hubble images to achieve similar results as the Webb telescope. Has this been tried before?

deleted 4y ago
[deleted]
detaro 4y ago
AI upscaling works if you want a prettier picture, but not if you want to actually know more. AI can't magically conjure information that isn't there, so if you upscale it has to invent details to fill in. Which is fine for some use cases, but not for science or truth-finding.
Kelm 4y ago
Sure you could try, but without getting real higher fidelity photos you’d never know how realistic the synthetic images are.
wetpaws 4y ago
No
lynguist 4y ago
It’s a valid thought, but it would really be like trying to take pictures of the sky from underwater and using AI to make it look like it was taken from out of water. This means: the AI has to predict what it is supposed to look like and for that we would need out of water pictures as reference in the first place which we didn’t so far! And then: even if we have these new out of water pictures as reference, the AI generated ones would still not show what is real, but instead a fiction. The fiction can look believable but it cannot be studied to derive facts from it. It’s like trying to study an AI generated language. This sounds like my friend who literally believes that buses will go extinct within 3-5 years as every vehicle will self drive. It’s not thought all the way through.
- Balgair 4y ago

angryGhost 4y ago

born too early...

echelon 4y ago
For the machines that will replace us.

supernova87a 4y ago

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. ** 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.

AQXt 4y ago
> especially since the images are stylized / colored anyway The thing that I don't like about the new images is the abuse of star flare effect. The colors are okay, but the flares... that's simply too much.
- tiagod 4y ago
  I don't think that's on purpose
- ygra 4y ago
  It's not an effect. It's a diffraction artifact that's a consequence of the telescope construction. Explained here for example: https://bigthink.com/starts-with-a-bang/james-webb-spikes/ https://bigthink.com/starts-with-a-bang/james-webb-spikes/

woevdbz 4y ago

It's striking how much more flamelike the structures appear to be, with the added resolution

avelis 4y ago

To touch the stars. To reach a galaxy. To dream of afar. And in the deepest space, see our ancestry.

throwaway4837 4y ago
It's hard to look at the Webb images without thinking that there must be life and technology out somewhere else in the stars.
- dylan604 4y ago
  Why does that only come from Webb images? You weren't getting that same sensation looking at the Hubble images before? If that's true, then welcome to the club! It took you a bit longer, but we're happy you're here now. ;P
  - throwaway4837 4y ago
    > Why does that only come from Webb images? Re-read comment.
    - dylan604 4y ago
      "It's hard to look at the Webb images without thinking..." What am I missing?
      - scrollaway 4y ago
        A charitable interpretation. You're making the assumption the poster meant they didn't have this feeling before. They might just be repeating that, once again, it's difficult to do this with Webb. Hubble is irrelevant. Anything else is irrelevant. They're talking about the pictures here in front of us.
        dylan604 4y ago
        cheap shot? I was absolutely agreeing with the sentiment. I clearly asked if the feeling was there before as well or if it was just from the new images. Thanks for your charity though

acqbu 4y ago

Hubble = iPhone 4S; Webb = Galaxy S22 Ultra

UberFly 4y ago

Considering these are just the initial "test" images there is going to be some amazing stuff to come over the years. Can't wait.

boomskats 4y ago

The sliders break when page zoom is anything other than 100% :/

bastardoperator 4y ago

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?

Mangalor 4y ago
These are just the first few images. Give it time.
- SiempreViernes 4y ago
  That's somewhat fair, but Hubble and JWST have fundamentally pretty similar resolutions so JWST will never get hugely better. What JWST can do is show new things that have never been seen before, but obviously it's a bit hard to schedule that sort of photos.
stevage 4y ago
With respect, the goal of a major scientific project is not to impress the layperson with pretty pictures.
- kmano8 4y ago
  Though of course the pretty pictures really help with increasing the appetite from the public for spending on projects like this.. and capturing people's imaginations is a necessary part of the long game.
echelon 4y ago
I can understand this sentiment, but I'm excited by the results we won't see: chemical spectra. Getting readings from the atmospheres of exoplanets will give us an idea of what population and percentages could harbor life. We may even get a whiff of some tell tale signs of industry, and that would change life on earth forever.
4y ago

8bitsrule 4y ago

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.

hparadiz 4y ago

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!

svachalek 4y ago
We've got very good pictures of our own planets thanks to probes that did flybys. Maybe I'm way off but I'm pretty sure JWST won't be able to beat those. I also wonder if it can even handle that much light, I know it can't look at the moon or it will burn out.
- hparadiz 4y ago
  Oh for sure it won't. I'm more interested in that as a tech demo.
Balgair 4y ago
Imaging Phattie/IX would also be pretty cool. It's been a while since we've discovered a real big-boy planet. https://en.wikipedia.org/wiki/Planet_Nine https://en.wikipedia.org/wiki/Planet_Nine

irrational 4y ago

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.

eevilspock 4y ago

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.

temptemptemp111 4y ago

SCAQTony 4y ago

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.

codq 4y ago
It's kinda like listening to music on vinyl vs. digital. High quality digital is clearly superior sonically, but vinyl has a dullness around the edges that is so aesthetically pleasing. I agree that the Hubble images are just pleasant to look at, warm and wonderful.
tmm84 4y ago
I'm glad someone here said this about them. I grew up seeing Hubble style images (non-IR) so I get the warm fuzziness they have. For me the one thing that gets me are the big shiny stars that seem to have big streaks going everywhere. They feel like lens flare in the photos.
izacus 4y ago
Ummm, pretty much all of those images are artificially colored so your comment basically just judges the person postprocessing the images and applying colors for detected wavelengths.

WalterBright 4y ago

My God, it's full of stars!

Unklejoe 4y ago

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.

dtgriscom 4y ago
https://blogs.nasa.gov/webb/2022/06/08/webb-engineered-to-endure-micrometeoroid-impacts/ https://blogs.nasa.gov/webb/2022/06/08/webb-engineered-to-en... Summary: they can see it in the data, but events such as this were expected and part of the lifetime of the telescope.

kumarvvr 4y ago

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?

Bjartr 4y ago
For 2, JWST uses reaction wheels to manage it's orientation. These are just heavy wheels it spins faster or slower to change it's own angular momentum. https://jwst-docs.stsci.edu/jwst-observatory-hardware/jwst-momentum-management https://jwst-docs.stsci.edu/jwst-observatory-hardware/jwst-m...
Laremere 4y ago
1. It can be pointed at any direction, just not at any time. It actually can't look directly away from the sun either, just to the sides. See https://jwst-docs.stsci.edu/jwst-observatory-characteristics/jwst-observatory-coordinate-system-and-field-of-regard/jwst-target-viewing-constraints https://jwst-docs.stsci.edu/jwst-observatory-characteristics... 2. Basically any satellite in use today uses spinning masses which it can speed up or down to change the direction it's looking. Angular momentum is conserved, but direction pointing isn't. Eventually due to uneven forces (eg, from the sun), these reaction wheels become "saturated" and some propellant is used slow the wheels down. Current estimates put the fuel running out in more than a decade. 3. It's an orbit in L2, past the Earth from the Sun's view. This orbit is unstable, and some of the fuel will also be used to maintain this orbit. 4. There is no refilling mechanism built in. It's likely once the propellant is out the mission will be done. There is the possibility of another spacecraft grabbing onto James Webb and pushing it for station keeping, but it wouldn't be able to refill it. One major innovation with the James Webb though is that it's refrigerator is closed loop, as otherwise running out of coolant would be the mission limiting factor.

tonymet 4y ago

what’s the practical application ?

Balgair 4y ago
Of astronomy?
- tonymet 4y ago
  of the James Webb Telescope
  - Balgair 4y ago
    I mean, it's pretty much asking what the practical applications of astronomy are. It's the marquee instrument now.
    - tonymet 4y ago
      feel free to share your thoughts
      - Balgair 4y ago
        seems pretty cool, lots of tech n stuff. How about you?
        tonymet 4y ago
        pretty illustrations , not much more
        Balgair 4y ago
        yeah, like who cares about heliophysics

ck2 4y ago

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-webb-take-pictures-of-our-solar-system-in-what-ways-will-they-differ https://space.stackexchange.com/questions/57492/can-james-we...

FloatArtifact 4y ago

How much and what type post processing are appled to these type of images?

mordae 4y ago
Most importantly the light frequencies have been mapped to visible spectrum.

TeeMassive 4y ago

Notice how the Southern Ring Nebula has expanded

deepzn 4y ago

The Carina Nebula is the most amazing photo. The level of detail now shown by JWST is breathtaking.

nabakin 4y ago
I think so too. I even made another comparison website for it because OP's website doesn't use the full resolution images. Each image is about 50 MB so it will take awhile for it to load. https://hubblevwebb.tiiny.site https://hubblevwebb.tiiny.site

Helmut10001 4y ago

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_Hubble_2009.full_denoise.jpg https://en.wikipedia.org/wiki/File:Stephan%27s_Quintet_Hubbl... [2]: https://johnedchristensen.github.io/WebbCompare/img/Stephans_Quintent_Webb.jpg https://johnedchristensen.github.io/WebbCompare/img/Stephans...

dan_mctree 4y ago
Overlaying them, it seems the JWST images have brighter galaxy edges and gas. This makes the galaxies look bigger, which in turn could make it appear as if the galaxies are closer together. Is that what you mean with 'progressed'?
- Helmut10001 4y ago
  Yes, I think you're right - also, the linked HUBBLE image from wikipedia is rotated a bit, which increases the effect that two of the 5 galaxies appear to be closer together in the WEBB image.

anigbrowl 4y ago

I'm slightly surprised they haven't gotten rid of the stellated hexagon artifacts with software.

mordae 4y ago
And replace them with what?
- anigbrowl 4y ago
  Nothing, that's kinda the point. I'm not talking about just deleting the pixels. If you know your measurement instrument introduces artifacts, you just move it around or use some ground-truth image until you map the artifacts and then subtract them out by convolution.

justanotherme 4y ago

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?

sandgiant 4y ago
What you find most exciting is a subjective thing. I don't have a clear answer, but you can browse through the list of accepted proposals in cycle 1 and decide for yourself: https://www.stsci.edu/jwst/science-execution/approved-programs https://www.stsci.edu/jwst/science-execution/approved-progra....

5350-uiop-1130 4y ago

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-reveals-steamy-atmosphere-of-distant-planet-in-detail https://www.nasa.gov/image-feature/goddard/2022/nasa-s-webb-...

ygra 4y ago
Isn't that look mostly a mapping of the observed wavelengths into the visible spectrum? I think at least for some of those images the different colors correspond to different chemical elements, which makes for pretty images _and_ some extra data that's interesting. For purposes of comparison with Hubble images it would also make sense to process them in the same way. But apart from that, there's the raw data, which is surely somewhere in the public domain, but that's way less useful in communicating those achievements to the public.

d--b 4y ago

These need to be adjusted for brightness... The Hubble ones are a lot darker which make things harder to spot.

dtgriscom 4y ago
I just filed an issue on the project. (Gotta look that gift horse in the mouth...)

sharmin123 4y ago

causi 4y ago

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?

smohare 4y ago

Damn near unusable of mobile. Cool.

mihaic 4y ago

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.

mihaic 4y ago

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.

cainxinth 4y ago
I believe the six spikes from JWST are because of its hexagonal mirror segments.
- FourHand451 4y ago
  This was my guess as well, but if it's correct, I don't understand why the Hubble images show 4 spikes. I thought Hubble's main mirror was circular, not a square.
  - cainxinth 4y ago
    As usual, wiki has the answer: https://en.wikipedia.org/wiki/Diffraction_spike https://en.wikipedia.org/wiki/Diffraction_spike >"...four spider vanes supporting the secondary mirror. These cause the four spike diffraction pattern commonly seen in astronomical images."

suddenexample 4y ago

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.

jhoechtl 4y ago

The post-processing in the webb images is hilarious. Marketing at its best.