Juno's Perijove-03 Jupiter Flyby, Reconstructed in 125-Fold Time-Lapse

2017-12-07 18:28 UT
Credit : NASA / JPL / SwRI / MSSS / SPICE / Gerald Eichstädt © cc by
Submitted By : Maquet-80
Mission Phase : PERIJOVE 3

On December 11, 2016, NASA's Juno probe successfully performed her Perijove-03 Jupiter flyby.

From JunoCam's raw image data, and SPICE navigation data, the movie reconstructs the two hours from ISO time 2016-12-11T16:00:00.000 to 2016-12-11T18:00:00.000 along Juno's trajectory in 125-fold time-lapse.

JunoCam is the Education and Outreach camera of NASA's Juno spacecraft. Juno's major science objective is looking beneath Jupiter's impressive cloud tops. In addition, JunoCam gives us a first close look at Jupiter's polar regions at wavelengths of visible light.

The reconstruction makes use of the 19 raw JunoCam Perijove-03 RGB images #94, #99, #101, #103, #104, #105, #107, #109, #110, #111, #113, #114, #116, #117, #118, #120, and #122.

In steps of five real-time seconds, one still images of the movie has been rendered from at least one suitable raw image. This resulted in short scenes, usually of a few seconds.

Playing with 25 images per second results in 125-fold time-lapse.

Resulting overlapping scenes have been blended using the ffmpeg tool.

In natural colors, Jupiter looks pretty pale. Therefore, the still images are approximately illumination-adusted, i.e. almost flattened, and consecutively gamma-stretched to the 4th power of radiometric values, in order to enhance contrast and color.

Blending between some of the close-ups nevertheless shows considerable changes of brightness, since those images have been taken close Jupiter's terminator.

The movie starts with a resonstructed in-bound sequence approaching Jupiter from north. Then the orbit approaches Jupiter down to an altitude of about 4,000 km near the equator.

This is followed by a transition into the outbound orbit, during which Jupiter's south polar region comes into view.

Rendering the still images of the movie took about four days on one up to three virtual CPU cores running in parallel.

The rendering software for the stills is proprietary. Trajectory data were retrived from SPICE kernels with the SPICE/NAIF tool spy.exe. from For combining stills to movie files, the tool ffmpeg has been used.

Blending may result in feature-doubling in overlapping scenes due to reprojection inaccuracies.

Most repetitive bright and dark camera artifacts are patched. Due to the intense radiation near Jupiter, several additional bright pixels occured. Those aren't patched in this animation.

In rarer cases, lightnings on Jupiter might also show up as bright pixels.

Sometimes, the edges of the raw images show up as black triangular areas in some corners of the movie rendition.

During blending, features may be doubled due to alignment inaccuracies of the blended scenes.

Some of the outbound images show subtle color banding. This might be a result of decompanding inaccuracies, which means undoing the way the camera encodes data numbers into raw data.

Some cloud motions are just perceptible, but very small from this distance, and within the short time. So, you may or may not notice them at a small number of locations during scene blendings.

Any residual issues in the movie are due to imperfect image processing.

The movie may nevertheless provide you an idea of Juno's Perijove-03 flyby.

JunoCam was built and is operated by Malin Space Science Systems in San Diego / California / USA.

Many people at NASA, JPL, SwRI, and elsewhere have been, are, and will be required to plan and operate the Juno mission.