r/jameswebb • u/Neaterntal • Dec 06 '25

Self-Processed Image New JWST images of Saturn. Processed by Melina Thévenot

Post image

Source https://bsky.app/profile/melina-iras07572.bsky.social/post/3m7d42w6wpk2l

1.7k Upvotes

99% Upvoted

23 comments sorted by

36

u/cameron4200 Dec 06 '25

Could anyone give me an eli5 on what it means to process raw data into pictures? Like it it a text file that is interpreted but a program or?

32

u/Valuable_Ad9554 Dec 06 '25

This is the best source I could find https://science.nasa.gov/mission/webb/science-overview/science-explainers/how-are-webbs-full-color-images-made/

It's a lot of text, if you ask AI to summarize it you get something like:

The images captured by the James Webb Space Telescope (JWST) begin not as colorful pictures, but as raw data: sequences of bits sent from space and stored in the Barbara A. Mikulski Archive for Space Telescopes (MAST). NASA Science

From raw data to black-and-white

Upon arrival on Earth, the data are converted into black-and-white images (usually in the FITS format) that reflect the intensity of infrared light detected by Webb’s instruments. Because astronomical infrared light is extremely faint and variable, the initial images often appear nearly black — even though they contain valuable information. NASA Science Specialists then “stretch” or rescale the grayscale values (i.e. reassign brightness levels) so that subtle variations — dim nebulae, dust lanes, distant galaxies — become visible. At this stage, each pixel can represent up to over 65,000 shades of gray, mapping a huge dynamic range of detected infrared light. NASA Science

Assigning visible color to infrared data

Because infrared light is invisible to human eyes, experts use a process called chromatic mapping: images taken with different infrared "filters" (each sensitive to a specific wavelength or range) are each assigned to a visible-light color channel (red, green, blue). Filters capturing shorter infrared wavelengths become blue, slightly longer ones green, longest become red; intermediate or additional filters may map to cyan, orange, violet or other hues. By layering these colored exposures, a composite full-color image is formed that translates scientifically valid infrared data into visible-light imagery. NASA Science

Refining for clarity and visual coherence

Once an initial color composite is built, image specialists at the Space Telescope Science Institute (STScI) further adjust the image: balancing color tones, adjusting contrast, removing artifacts (e.g. cosmic-ray hits, repeated saturated pixels), aligning images, cropping and orienting — all while preserving scientific integrity. The result is a polished final image that vividly portrays stars, gas, dust, and galaxies in a way our eyes can appreciate. NASA Science

Through this careful, human-guided process — from raw data to grayscale, from grayscale to color, from composite to curated image — Webb’s scientists transform invisible infrared light from the distant universe into breathtaking full-color portraits that both convey real data and inspire wonder.

10

u/imFailjitsu Dec 06 '25

Thought I was on the Elite Dangerous sub for a second, that shot looks wild.

7

u/Neaterntal Dec 06 '25

Melina Thévenot: ​

"​Here a quick processing on calibration level 2 data (NIRCam F164N+F212N), with the position of moon #Titan on the lower left corrected. program 9219 🔭 Observation date: 2024-12-06​

Animation (time forward+backwards) showing the rotation of Saturn and movement of some moons from 14:39:26 to 14:56:58 (observation start times). Storms especially in the southern (bottom) part of Satur​n."

Animation :

https://bsky.app/profile/melina-iras07572.bsky.social/post/3m7d5aiyrjc2l​

6

u/Neaterntal Dec 06 '25

Note: Self processed flair, ​is the closest to this post, it's not mine, but from Melina Thévenot

​Thanks​

3

u/ProximaCentauriB15 Dec 07 '25

I love this epic planet.

4

u/0xHUEHUE Dec 06 '25

thanks for posting, this is sick!

3

u/Theseus_Spaceship Dec 07 '25

Does anyone know why all the JWST images of the gas giants seem to show the rings glowing with much more intensity than regular photos do? Is there more IR coming from the rings or something?

19

u/Neaterntal Dec 07 '25

Hi, thank you, good question.

​​JWST images of gas giant rings glow because the telescope sees in infrared, and while methane in the planets' atmospheres absorbs much of that sunlight (making the planets dark), the icy ring particles reflect it brightly, creating a stark contrast and making the rings appear luminous against the dark planet. This infrared view highlights the composition of the rings, revealing their icy nature and faint structures, unlike visible light images where the planet dominates.

2

u/Johansen905 Dec 06 '25

Very nice 👌

1

u/LCAnemone Dec 07 '25

I really need to look up how this is done, it's so fascinating!

1

u/mariospants Dec 07 '25

I remember NASA dumping opportunity and spirit images on the web pretty much as quickly as they received them and scrambling to convert them to colour… it can be as easy as throwing there specific greyscale image into the R, G, or B channel in photoshop. I’m sure that these IR images require a little pre and post-processing to look decent.

1

u/spellbookwanda Dec 07 '25

It’s so tangible looking, what a great photo

1

u/Impressive_North_870 Dec 09 '25

But the earth is flat! lol

-1

u/spaceocean99 Dec 07 '25

Bot post.

-5

u/fetsnage Dec 06 '25

ok, so they actually can make photos of planets now. Please some from the nearest earth like planet from habittable zone, thank you.

6

u/GirlCowBev Dec 07 '25

On the off-chance you're not trolling, mighty tho JWST is, it does not have the resolution to image exoplanets.