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Show HN: A JWST/Hubble deepfield comparison on a zoomable/pannable map interface

61 points| outputchannel | 3 years ago |academo.org | reply

36 comments

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[+] nabla9|3 years ago|reply
JWST and Hubble have roughly similar angular resolution. Hubble marginally better. JWST needs larger mirror for the same angular resolution because it uses longer wavelengths.

  Hubble: 0.04  arcsec at 500 nm 
  JWST:   0.068 arcsec at 2 μm
The difference is in wavelengths, image quality, and light collecting ability (size of the mirror). Hubble has to stare longer into a same spot to collect the same amount of light as JWST.

(If I remember correctly JWST took this image in less than 12 hours, Hubble stared at it for much longer. Correct me if I'm wrong).

[+] 0x_rs|3 years ago|reply
Hubble's composite of SMACS took 5 orbits, which ends up being about a couple hours maximum. Most websites talked about the deep fields such as XDF (hundreds of orbits) while showing the comparison between the RELICS and JWST pictures, which I believe was very misleading from how this is repeated. Not to detract from its capabilities, of course.
[+] sph|3 years ago|reply
Would JWST have made a more detailed picture if it had stared on that spot as long as Hubble did?
[+] RcouF1uZ4gsC|3 years ago|reply
As an aside, does anyone on HN know why one telescope’s name includes a first name and the other doesn’t.

We don’t call the first telescope the Edwin Hubble Space Telescope

[+] gumby|3 years ago|reply
I think it's because they are two syllables. After a short time objects named after people* (Carnegie Mellon, FDR Drive etc) tend to lose the association with the person so honored and just become strings. This is doubly so for names of international scope.

Think of Google, Facebook, Netflix, Workday, Coinbase: two syllables, each name an iamb (which is especially effective in English). Sure, there are numerous counterexamples (microsoft, Amazon), but generally the corners get knocked off and even turn into acronyms in public usage (GM, GE).

Single syllables are too short for infrequently used words (this appears to be true for any language) -- you don't want to waste a lot of time saying "am" since you say it a lot; when you say "biceps" you want enough variability that your brain has time to parse it.

[+] q1w2|3 years ago|reply
Webb is a much more common surname than Hubble.
[+] Synaesthesia|3 years ago|reply
This isn't a real image of an exoplanet right? The one in the background. Nowhere does it say that, which I think is beyond the ability of even JWST, to resolve an exoplanet at 50 light years?

https://www.nasa.gov/image-feature/goddard/2022/nasa-s-webb-...

[+] hrnnnnnn|3 years ago|reply
The image in the background is an artist's rendition. The graph is the real image.

Exoplanets are too far away and too small to image directly.

[+] revskill|3 years ago|reply
These are annoying to me because lacks of real difference from a senior astronaut viewpoint. As a normal user, the only difference i could see is just "brighter", anything more to add to the details ?

Else i could say, just the same.

[+] atoav|3 years ago|reply
JWST shows a much bigger part of the wavelength spectrum. That means it can image things that would just not show up in Hubble.

E.g. think about far away galaxies that have been redshifted so much (due to the expanding universe) that they fell below the lower wavelength threshold of Hubble.

[+] testcase_delta|3 years ago|reply
Zoom in on a small section of sky and toggle between James and Hubble. James reveals many additional galaxy in each tiny slice of image. Probably hundreds or more in that one image alone.
[+] falseprofit|3 years ago|reply
Check out some of the reddest galaxies in the Webb image. Even the big ones are entirely invisible on the Hubble image.
[+] holoduke|3 years ago|reply
Would there be a moment we cannot zoom in further because we hit the event horizon with the jwst? Or are there still hidden galaxies behind what we can see with the jwst?
[+] falseprofit|3 years ago|reply
The furthest back potentially visible stuff before the dark age won’t be galaxies, which formed after the first stars. We still have never seen a first generation star, and I’d be surprised if Webb could.
[+] fvold|3 years ago|reply
I want to see a comparison of the infrared from Hubble vs the infrared from James.

I also want to normalize calling JWST just "James" :)

[+] Synaesthesia|3 years ago|reply
The Hubble only went into very near infrared, nothing like JWST. Also JWST is a million miles from earth so it is ultra cold.

I like "James Webb Science Telescope" for JWST.

[+] dirslashls|3 years ago|reply
Nice. It would be good to have a way to reset to get back to the initial state after zooming/panning.
[+] arriu|3 years ago|reply
I love that there is a star showing some drift
[+] Azrael3000|3 years ago|reply
There's no drifting there. What you are seeing is gravitational lensing. The light of (most likely a galaxy) is bent around another galaxy or star which distorts its appearance. Also this means it can potentially show up multiple times on the image (e.g. opposite side w.r.t. the lensing object)
[+] aardvarkr|3 years ago|reply
This is incredible. Thanks for sharing it!