Juno is in a 53-day orbit. When it passes close to Jupiter (“PeriJove”
or “PJ”) we will take as many pictures as we can. The number of pictures that we take is
limited by the amount of onboard data storage that we have for JunoCam, so we
have to be selective. The images are
collected as we go from the north pole of Jupiter to the south pole, which
happens in a brief 2 hour portion of the orbit.
On any given perijove pass we will only be able to image targets in a
narrow swath of territory the spacecraft flies over (“groundtrack”).
Juno’s orbit geometry is evolving so we will carry out
campaigns rather than voting on specific targets. Campaigns are focused on a specific science
theme and take advantage of the changes in lighting.
What happened to Voting?
Up through PJ8 everyone could vote on their favorite Point
of Interest (POI) and those rounds can be viewed here. Changes in the orbit and mission plan mean
that we are no longer selecting targets by vote.
There will still be a voting page for every orbit and we
will describe the specifics of each perijove pass such as the spacecraft
orientation. Because of the challenges
to predict the Points of Interest that will be in the JunoCam field of view we
are now timing the image collection by latitude and/or executing campaigns.
We will take polar images on every PJ pass to assemble
timelapse sequences to study the dynamics of the circumpolar cyclones. Between the north and south pole images will
be timed to get complete latitudinal coverage.
The rest of the resources will be used for campaigns. Options are to look for lightning, take
multiple methane images to study high altitude hazes, study Jupiter’s ring,
take stereo pairs for cloud altitudes, image Galilean moons when available, etc. We will keep the Voting Round discussion for
comments on what would be best. We are
hoping that you enjoy being a part of this process, that you enjoy being a member
of the JunoCam team.
Voting Round :
CLOSED : 2017-05-11 17:00:00
Perijove on : 2017-05-19 06:00 UT
About This Round
At PJ6 the orientation of the Juno spacecraft will be optimized for gravity studies, to understand more about the interior structure of Jupiter. That means that we will have radio contact with the spacecraft throughout the perijove pass. That in turn means that we will be able to downlink data the entire time, and we won't be limited by our onboard storage so severely.
Given this situation, we would like to increase the number of images in the polar timelapse sequence to study the intriguing motions of the storms around the poles. We will also be able to take just as many images on the pass across the midlatitudes and equator as we did on PJ5 - so we expect to be able to collect just as many images of Points of Interest that you vote on! Help us with that selection by weighing in on which sites you think are most important and, of course, voting.
Perijove Predict MapWinner Selection
We had 20 Points of interest to select from for the PJ6 swath.
We started the process of generating image commands as soon as the voting closed. We looked first at the predictions of what time an image would need to be taken to get a particular POI. We have constraints on how closely together we can take images, because an image must be moved from the camera to the spacecraft computer before we take the next one. That means if targets are closer together in time than 90 sec we combined them. We took the time that corresponded to the higher priority target, but we will get the other POI's in the image.
This time the POI’s were close enough together in latitude that we were able to get all of them! It also helped that the spacecraft will be in contact with the earth transmitting data throughout the flyby, so we had more data volume to work with on this pass.
The list of POI’s we will image in order of the votes they received is as follows, with the “+” indicating targets we combined:
A whirl of a pearl + String of Pearls
The darkest spot + A multi-colored band
little greenish place + Hotspot + Hotspot tail
The big red stripe
Scott polar cap
Gas Irregularity + Spot of Brahman
Carl Sagan’s jawbreaker + South tropical zone
Things seem quiet in the south + Southern FFRs
Southern edge of northern FFRs
Great polar spot
These images will be available after we get "C kernels" which is a file with the spacecraft orientation as a function of time. This data is necessary for us to process the data before we put it on the website. It takes two days for us to get that data from the navigation team. Perijove 6 is on Friday, May 19, so we expect to start posting the images on Tuesday, May 23.
Voting has closed for this round. View results in the Candidates list below. Be sure to keep an eye on the Processing Gallery for images of POIs/Campaigns selected during this round of voting taken by the JunoCam!