Commons:Featured picture candidates/File:Neptune Wide Field (NIRCam).jpg

From Wikimedia Commons, the free media repository
Jump to navigation Jump to search

File:Neptune Wide Field (NIRCam).jpg, featured[edit]

Voting period is over. Please don't add any new votes.Voting period ends on 28 Dec 2022 at 20:53:56 (UTC)
Visit the nomination page to add or modify image notes.

Planet Neptune and seven of its moons, most prominently Triton in blue, together with galaxies and stars. Infrared image.
  • Gallery: Commons:Featured pictures/Astronomy#Neptune
  •  Info created by NASA, ESA, CSA, STScI, Joseph DePasquale (STScI), Naomi Rowe-Gurney (NASA-GSFC) - uploaded and nominated by Habitator terrae -- Habitator terrae 🌍 20:53, 19 December 2022 (UTC)[reply]
  •  Info Perhaps not so clear cut impressive as images of nebulae, but stunning because of the content wise contrast between the galaxies and Neptune (with rings, which is pretty rare for images of neptune).
  •  Support -- Habitator terrae 🌍 20:53, 19 December 2022 (UTC)[reply]
  •  Question I am tempted to oppose this as it seems to be an image created from data and bears no relation to what you would 'see' in a telescope. But I am no expert. It just looks so false. Charlesjsharp (talk) 22:07, 19 December 2022 (UTC)[reply]
    Not expert either, but I can tell this much: most of the light wavelengths can't be seen by the human eye. JWST's sensors can catch these, so mapping to visible wavelengths can be necessary. This can be a calculated (like when the light have traveled for so long it's shifted toward the reds / invisible infrared, so we just "shift back") or just arbitrary. This photo is probably the later case (it's not far enough so that the infrared light is shifted from visible light). Hope it's not too much bullshit that I said... - Benh (talk) 08:25, 20 December 2022 (UTC)[reply]
    Follow-up  Question Does this mean that we should understand and handle this rather as some kind of Computer graphics than as a photo? --Aristeas (talk) 09:36, 20 December 2022 (UTC)[reply]
    It's signal processing, so yes to me. But it's real stuff, just we must bear in mind the colors are mapped because the camera used is NIRcam (near infrared, so I assume it's not visible light). I guess they use a mapping which makes sense. But I think I've said too much and I hope some astronomer corrects me. - Benh (talk) 13:00, 20 December 2022 (UTC)[reply]
    @Benh: For the mapping and the filters click on link and scroll to "About The Image". Habitator terrae 🌍 16:46, 20 December 2022 (UTC)[reply]
    (Edit conflict) Just because we now have instruments that detect things our human eyes can't see, doesn't make the image any less real. Look at it this way: A digital camera's sensor records photons of certain wavelengths. It does some very fast calculations with the software in the camera and the result is an image of pixels we can see. JWST's sensors does the same thing. It records photons of other (non-visible) wavelengths, software does some calculations (although way more advanced than in a normal digital camera) and this results in pixels that we can see. Yes, the colors are added/enhanced and not exactly what our eyes would see, but in early B&W photography when colors were not rightly represented (like the blue-yellow switch), people still didn't think the photos were 'fake'. Our everyday phone cameras can now record IR light, from say a remote control, process it and give it a color we can see, and we don't hesitate to call that a true photo.
    A computer generated image is an imagined picture, with user and AI extrapolating and guessing how things might look. JWST's images are not made up or imagined, they are very exact representations of what is out there. We are just not used to seeing it so clearly yet. Imagine how the Lumière brothers would react to seeing an IMAX nature documentary, they would probably also think it looked false.--Cart (talk) 13:53, 20 December 2022 (UTC)[reply]
    Thank you for your explanations, Benh and Cart! I did not want to devalue the image with my question, it was just a question. --Aristeas (talk) 14:53, 20 December 2022 (UTC)[reply]
    That's why I didn't nominated this image, with artifical AI-noice-reduction. Habitator terrae 🌍 16:48, 20 December 2022 (UTC)[reply]
    @Charlesjsharp: By that standard you would be forced to oppose many pictured in Commons:Featured pictures/Astronomy like File:Pluto-01 Stern 03 Pluto Color TXT.jpg or File:Jupiter Showcases Auroras, Hazes (NIRCam Closeup).jpg. It has many relations to what you would "see" through a telescope. Fully red objects don't go to fully blue and vice versa. This comes from the fact, that green is a not existing color for stars. Therefore the basic colors don't fully negating themselves. Furthermore: From a technical point of view, this sensor uses the same process as normal cameras: The only difference is, that it doesn't uses the anthropocentristic filters red, blue and green, which evolved to life on earth and not to view stars, but some infrared (which might find their equivalent in some other species than human). Habitator terrae 🌍 16:26, 20 December 2022 (UTC)[reply]
    OK, so if it is imagined that's fine as long as it is described as such. And the image of Neptune itself is ground-breaking. My problem with it is the whole image, which must be a composite. The planet and one nebula are illustrated with the same brightness; not to mention Neptune's moon Triton with its six-pronged reflection. The two FPs you link to are fine. Charlesjsharp (talk) 17:00, 20 December 2022 (UTC)[reply]
    @Charlesjsharp: Why do you think this is a composit, or what do you mean with this? This "six-pronged reflection" isn't to the infrared light or some composit, but because of the form of the mirror (which is needed in normal telescopes) and the high light concentration at one point. See for this en:Diffraction spike. Habitator terrae 🌍 17:20, 20 December 2022 (UTC) PS: Do you mean with "composit", that this is a composit of the different reflection of the different parts of the mirror??[reply]
    @Charlesjsharp I just got from Habitator's reply that "six-pronged reflection" means diffraction spikes. If you look closely, there are 8 spikes (two verticals as well). It's probably because the primary mirror is made of smaller hexagons and because the secondary mirror is held by three tubes. I think we can safely say these are acceptable tradeoffs given all the constraints that come with sending such an incredible telescope so far. You can't review these like you'd review a photo taken with a "regular" camera. - Benh (talk) 18:07, 20 December 2022 (UTC)[reply]
    Thanks for the explanation. I still can't understand why some of the planets/moons/stars have the refraction and others don't. But I'm not opposing this anyway; just saying I am not that impressed. Charlesjsharp (talk) 18:22, 20 December 2022 (UTC)[reply]
    The reason is the concentration of light. Stars often have disffractions, because the source of their brightness come from one "small" source, while galaxies (often) have a more scattered type of brightness. The reason for Triton to be so bright, is that is an big icy moon, which reflects a lot. Habitator terrae 🌍 19:23, 20 December 2022 (UTC)[reply]
    The same can be seen in this image of an airport at night: The point-shaped light sources have diffraction spikes (what photographers like to call "starburst"), but the large rectangular ones don't. --El Grafo (talk) 09:24, 21 December 2022 (UTC)[reply]
    No pb with that. But I'd like to underscore that sometimes the context and meaning of the photo outweights the rest. A bit like photos of animals are better when taken in the wild instead of a zoo... don't you think? Anyhow. Enough digression, apologies for that. - Benh (talk) 20:59, 20 December 2022 (UTC)[reply]
    As Habitator said all stars (except the Sun) can be considered point light sources regardless of their magnitude simply because they are so far and so small. You can pretty much think of them as one single stream/column of photons. Most other objects have some dimensionality which means more than one stream/column of photons will reach your eye/the camera. This is also the reason all stars seem to "blink" on the night sky but planets don't (and how you can immediately tell whether you're looked at a planet or a star). Now, single point sources diffract much easier than other sources, but if the light intensity is large enough you'll get diffraction spikes with those sources as well (see Triton in this example). In a way the strength of the diffraction spikes in any night photo can be explained by the relation of the sensor size vs the size of the light source as it passes through the aperture. The more you stopped down the smaller this size is and the more point like the light sources become. -- KennyOMG (talk) 22:15, 24 December 2022 (UTC)[reply]
    It's a composite in the same way as HDR and focus stacked images are composed of a number of photos. I guess you could call it an "Astro HDR" if you like. --Cart (talk) 17:27, 20 December 2022 (UTC)[reply]
    I don't think so. HDR and focus-stacked images are taken at (almost) the same time from (almost) the same position. A composite is a selection of different images combined into one. That's what this looks like. You are suggesting that they extracted the Neptune image from this 'wide angle' shot. That would surprise me. Charlesjsharp (talk) 18:22, 20 December 2022 (UTC)[reply]
    In fact the different frames were tacken at almost the same time (all on 12 July 2022) at almost the same position (L2 of Earth-Sun with the move of less than one day). I furthermore remind, that this is a considerable shorter time compared to e.g. this image. This short times are a feature of JWST. Of course, this is a image of a solar system object and not of galaxies. Habitator terrae 🌍 19:20, 20 December 2022 (UTC)[reply]
    (Edit conflict) I think you've misunderstood what this image is. This is not Neptune and bunch of images of other galaxies thrown together in one picture, it's what the sky looks like from that point of view when all the stars and galaxies are brought up to the same visibility/brightness, like you do with HDR. They are there all the time, but we have not been able to see them this well until now. Have you seen how big the Andromeda galaxy would look in the sky if you just bring up the light with HDR? You talk about the image of Neptune and its rings being 'extracted' from this, like this was just an ordinary photo. The photos we get from NASA are only what they release. My guess is that this was originally an extremely large image. The part with Neptune and its rings was released as one photo, then the whole wide view was downsized by NASA to fit being shown over the internet and that is what we see here. I also suspect that the JWST sensors can, in simple terms, to a degree zoom in and out on objects they want it to record. You have to let go of thinking about this extraordinary machine in terms of normal cameras and telescopes. --Cart (talk) 19:50, 20 December 2022 (UTC)[reply]
    "HDR" is NOT what it's about. The main point of astronomy is to study observable (by eye, instrument, any wavelength, etc) characteristics and how these relate to each other. Adjusting an image like you would in case of a HDR would be falsifying scientific data. What they do is take images at different wavelengths and combine these into one composite image. You can think of it in away that the Leica M10 monochrome can only take monochrome images however if you take 3 images, one with a red, one with a green and one with a blue filter, then combine these into one composite you'll get a true color image. But, again, it has nothing to do with fiddling with the brightness of objects observed. -- KennyOMG (talk) 22:03, 24 December 2022 (UTC)[reply]
    just to get you an idea, how the raw data looks like: Here an raw image (which is part of the image in green), with an exposure of 7515.740 seconds. This was parallel taken, by what is shown in blue, starting on 2022-07-12 06:28:25.913 (with perhaps, I don't know filtering the noise out with parts of the exposure). Red and orange hat an exposure of 1878.935 seconds, starting with 2022-07-12 06:52:35.448. Habitator terrae 🌍 20:03, 20 December 2022 (UTC)[reply]
    In Addition, perhaps, that's what's the problem for some, the exposure was more like a "scanner" and didn't all the time viewed the same region of the field because of the size. That's why they end up with different intensities, as shown, if you automatic put all the raw data for one wavelength together (as linked). I presume for the processing of this image they used the original "small" exposures to remove all the noise and different intensities across the image. But all of this seems to be pretty standard for most JWST images. Habitator terrae 🌍 10:54, 21 December 2022 (UTC)[reply]
    Thank you for the link to the raw data example. This makes me much more confident of the final result. --Aristeas (talk) 08:12, 21 December 2022 (UTC)[reply]
  •  Support I think this needs to be featured and explained, so the knowledge has more opportunities to be spread. It's fascinating how we can see Neptune's rings. - Benh (talk) 13:04, 20 December 2022 (UTC)[reply]
  •  Support This is impressive for a space photo. --SHB2000 (talk) 08:03, 21 December 2022 (UTC)[reply]
  •  Support Thank you for all the explanations, Benh, Cart and Habitator terrae! --Aristeas (talk) 08:12, 21 December 2022 (UTC)[reply]
  •  Oppose Neptune and Triton in the center are interesting, but compared to the Hubble Deep Field image the wide field is not outstanding. -- IamMM (talk) 09:11, 21 December 2022 (UTC)[reply]
  •  Support The wow takes a while to materialize in this one, but it's there. --El Grafo (talk) 09:32, 21 December 2022 (UTC)[reply]
  •  Support --Ermell (talk) 11:26, 21 December 2022 (UTC)[reply]
  •  Support per El Grafo. -- Radomianin (talk) 15:31, 21 December 2022 (UTC)[reply]
  •  Support Daniel Case (talk) 03:29, 22 December 2022 (UTC)[reply]
  •  Support --Wieggy (talk) 20:52, 22 December 2022 (UTC)[reply]
Confirmed results:
Result: 9 support, 1 oppose, 0 neutral → featured. /--A.Savin 23:03, 28 December 2022 (UTC)[reply]
This image will be added to the FP gallery: Astronomy#Neptune
Retrieved from "https://commons.wikimedia.org/w/index.php?title=Commons:Featured_picture_candidates/File:Neptune_Wide_Field_(NIRCam).jpg&oldid=720675476"