Skip to main content


With the amazing images coming back from Juno's flyby of Io, I finally took a stab at processing some JunoCam images. This image shows Io's north polar region from 2839km distance.

https://flic.kr/p/2ppYk8v
Credit: NASA/JPL-Caltech/SwRI/MSSS/Simeon Schmauß

#Io #Jupiter #Juno #Astrodon #Solarocks #Space #Astronomy

reshared this

in reply to Simeon Schmauß

I processed this image from the individual framelets, which I preprocessed with a python script and then assembled in PTGui.
This allowed me to retain the complete horizon which is often lost with JunoCam images.
in reply to Simeon Schmauß

I also developed a color calibration for the JunoCam filters based on the CIE1931 color system. This allowed me to process the image in approximate true colors as the human eye would see them.

However, this wasn't an easy task because the JunoCam RGB filters don't match the spectral response of the human eye very well. Particularly the red filter is way too sensitive in the near infrared and Io's surface is especially reflective there.

in reply to Simeon Schmauß

In addition to the common ColorChecker 24 spectral target I used an Io reflectance spectrum (Spencer et. al. 1995), so I could better fit my calibration matrix to the spectral characteristics of Io.

Even with weighting the Io spectrum, my calibration only managed a dE of the Io reference target of 8.3 which really isn't great. That's why I'm only calling it an "approximate" true color image for now.
There is probably room for improvement by using more representative spectra.

in reply to Simeon Schmauß

Even with those compromises my image still looks rather similar to
@volcanopele's Galileo true color processing of Io.
I might try to process/calibrate some Galileo and Voyager images in the future.
https://www.planetary.org/articles/2629
in reply to Tom Montgomery

@tom30519 Not at all, but I would give everything to see it with my own eyes from orbit (in a very radiation hardened spacecraft that is) 😁
in reply to Simeon Schmauß

With currently available transportation, the trip there is about 5 years, and, presumably another 5 to come back to Earth! 🚀

I think I'll be content with the amazing images that Juno is providing! 😃

in reply to Simeon Schmauß

what are the red in the upper right part of the image? Looks like wind spread it in lines? Oh oh and what is the orange/yellow ring in the lower right part?