Perijove 31 flyby experimental animation

2021-05-31 21:57 UT
Credit : NASA / JPL-Caltech / SwRI / MSSS / Björn Jónsson © cc nc sa
Submitted By : Bjorn_Jonsson
Mission Phase : PERIJOVE 31

This is an experimental animation showing Jupiter as seen from the Juno spacecraft during its perijove 31 flyby on December 30, 2020. The flight path follows the spacecraft from 21:08:59 to 22:43:29 on December 30, 2020. In this movie everything happens about 13 times faster than it really did. The flight path is taken from the relevant SPICE kernels.

To create the animation I used all of the JunoCam RGB images from image PJ31_7 to image PJ31_43 and also a small patch from image PJ31_47. This is a total of 34 images. An important goal was to show everything at the highest resolution possible. This made it impossible to assemble all of the images into one map-projected mosaic of Jupiter; that map would have been far too big (about 160,000 x 80,000 pixels). Instead, several seamless map-projected mosaics covering different parts of the planet at various resolutions were created. The resolution of these maps ranges from 80 pixel/degree to 450 pixels/degree. The effects of the varying solar illumination were removed using a slightly modified Lambert illumination model combined with a new limb darkening function. The maps were then processed to enhance the contrast and colors a bit.

The animation was then rendered by using different maps for different parts of the animation. When rendering the animation, shading was applied using the same illumination model as the one originally used to remove the illumination, i.e. modified Lambert and a new limb darkening function. The parameters were slightly modified in order to slightly increase the brightness of dimly lit areas near the terminator and poles relative to bright areas.

Overall, Jupiter's appearance should be fairly realistic but some artistic license has been used. As mentioned above, the contrast was increased but not as much as I usually do in the enhanced versions of images I have processed. This makes various subtle details more obvious. Jupiter didn't look realistic with a perfectly sharp limb so I also added some atmospheric effects. These effects are a bit exaggerated, especially in the dimly lit polar areas. For example Jupiter's bluish sky at the limb is brighter and more conspicuous here than it is in most of Juno's images. On the other hand the atmospheric effects reduce the overall contrast a bit - but not so much as to cancel out the previously mentioned contrast enhancement.

To show Jupiter in its full splendor the animation has a very wide field of view (90°).