Juno Extended Mission, Perijove 34-76 Options

[Antdoghalo]

Large Swaths of Ganymede may be improved depending on how close it is. Though don't expect anything like Solid State Imaging.

[Brian Swift]

Mike, do you know yet if MSS will be doing any additional (beyond current operations) JunoCam work due to extended mission?

[mcaplinger]

Mike, do you know yet if MSS [sic, it's MSSS] will be doing any additional (beyond current operations) JunoCam work due to extended mission?

Planning the satellite encounters and processing the results is obviously beyond the scope of what we've been doing so far, so yes.

[mcaplinger]

Large Swaths of Ganymede may be improved depending on how close it is.

Bolton's presentation to OPAG (linked upthread) said the minimum altitude of the Ganymede flyby was 1000 km, at which Junocam would get ~670 meters/pixel resolution. It's a bit hard to say what the best resolution in the current coverage is, but it's probably better than that in most places, and the gaps are near the north and south poles, which AFAIK won't be seen in this encounter. As I said, we won't know for sure until the final flyby geometry is established. Note that this first Ganymede flyby is in mid-2021.

[I guess I should mention that my perspective is obviously Junocam-centric and JIRAM will also get images, which are both higher-resolution and not subject to the limitations of darkness.]

[antipode]

Magnetometer science at the Ganemedian magnetosphere might be interesting too. Are the flyby geometries favourable?
I know the magnetosphere is tiny.
Also - imaging of the Ganemedian ultraviolet aurora!

P

ps I better read those posts, maybe its in there. I'm excited though. Always great to get bonus unexpected science (thinking of Deep Impact etc)

[mcaplinger]

I better read those posts, maybe its in there.

Start with https://www.lpi.usra.edu/opag/meetings/opag...Bolton_6011.pdf and
https://www.lpi.usra.edu/NASA-academies-res...nior-Review.pdf

It doesn't look like the final extended mission proposal from Juno was made public, so you have to infer what it may have said from the review of it.

[mcaplinger]

we won't know for sure until the final flyby geometry is established.

The SPK file for the current baseline (which may change) is at https://naif.jpl.nasa.gov/pub/naif/JUNO/ker...1021_210111.bsp if people want to look at it.

See https://naif.jpl.nasa.gov/pub/naif/JUNO/ker..._210111.bsp.lbl for info on the flybys.

CODE

Satellite Flyby Events
Satellite Time Range vInf Lat W.Lon Phase Alt.
km km/s deg deg deg km
Ganymede 07-JUN-2021 16:56:07 UTC 3676.38 18.427 23.63 55.23 98.2 1045.2
Ganymede 20-JUL-2021 16:48:30 UTC 52631.20 17.885 -22.46 235.80 80.9 50000.0
Europa 16-OCT-2021 08:46:28 UTC 82920.00 22.502 50.00 217.54 89.8 81359.2
Europa 24-FEB-2022 18:15:38 UTC 48472.17 23.501 77.33 128.35 100.6 46911.4
Io 05-JUL-2022 04:55:50 UTC 87913.57 29.490 77.93 172.05 92.8 86092.0
Europa 29-SEP-2022 09:36:04 UTC 1916.98 23.581 -0.84 49.08 130.1 356.2
Io 14-DEC-2022 23:16:05 UTC 65547.98 30.270 75.99 112.84 100.5 63726.4
Io 01-MAR-2023 01:32:03 UTC 53390.33 29.020 55.00 208.59 71.0 51568.7
Io 16-MAY-2023 03:15:49 UTC 39219.03 29.290 54.18 206.71 67.8 37397.4
Io 31-JUL-2023 04:57:16 UTC 23988.43 29.723 65.11 188.22 77.3 22166.8
Io 15-OCT-2023 06:47:26 UTC 13448.57 29.811 65.86 182.35 77.4 11627.0
Io 30-DEC-2023 08:36:10 UTC 3316.44 30.027 63.69 94.23 108.9 1494.8
Io 03-FEB-2024 17:48:50 UTC 3245.51 30.139 -32.67 35.81 143.6 1423.9
Io 09-APR-2024 05:00:37 UTC 20373.15 29.988 -66.56 294.64 81.5 18551.6
Io 25-NOV-2024 05:33:31 UTC 85679.33 28.794 -55.42 278.23 74.5 83857.7
Io 08-MAY-2025 18:03:36 UTC 90943.96 30.643 -58.63 339.88 113.7 889122.4

[volcanopele]

Expect an animation of the Io encounters on YouTube by end of day (it will assume HGA to Earth pointing, which at least for the Io flybys based on the OPAG presentation is a reasonable assumption)

[volcanopele]

Placeholder post for Io flybys based on spk_ref_210111_251021_210111.bsp :

ground track map:




Neat view before the PJ57 encounter:

[stevesliva]

(it will assume HGA to Earth pointing, which at least for the Io flybys based on the OPAG presentation is a reasonable assumption)

...because radioscience?

Groundswaths are very exciting!

[Phil Stooke]

This map (from here:)

https://astrogeology.usgs.gov/search/map/Ga...IM3237_Database

shows image coverage for the USGS basemap of Ganymede. There will be small areas of high resolution coverage scattered through this.

It suggests to me that any swath of imaging from Juno's closest pass will improve our maps to some extent.

Phil

[volcanopele]

It suggests to me that any swath of imaging from Juno's closest pass will improve our maps to some extent.

Looks like best imaging along terminator at around 48°W. best "swath" looks centered around 30 W, covering 15 south to 70 N

[Antdoghalo]

Placeholder post for Io flybys based on spk_ref_210111_251021_210111.bsp :

ground track map:

That map reminds me of the early Cassini days of observing Titan and anticipating what will we find with each swath. Similar with Io since it changes so much.

[mcaplinger]

Looks like best imaging along terminator at around 48°W.

Something like that, but note that I think this is a little past closest approach. We come in on the night side so the best visible imaging is on the outbound leg, where the resolution is going down fairly quickly.

It'll be cool regardless, but I don't want to oversell it.

[Bjorn Jonsson]

Ganymede was actually fairly well imaged by the Voyagers since V1 flew by Ganymede when outbound whereas V2 did so when inbound. Later Galileo filled some gaps (plus limited 'postage stamp' hi-res images).

However, there are some really poorly imaged areas on Europa because only one of the Voyagers (V2) obtained moderate resolution images and most of the many Galileo flybys occurred over the antijovian hemisphere (also the HGA problem prevented the return of lots of gap-fill images from non-targeted Europa flybys like G7). The coverage is especially poor near longitude 130 degrees and there are also some 'annoying' patches of low resolution coverage near longitude 70 degrees and longitude 320 degrees. I haven't checked the new Juno SPKs yet (e.g. spk_ref_210111_251021_210111.bsp) so I don't know if Juno has opportunities to image these areas at better resolution but I suspect not.

The two close Io flybys look interesting to me since the ground tracks posted above are over a relatively poorly imaged area.

Of course this is exciting but I suspect the satellite data from JIRAM or even the magnetometer may turn out to be far more interesting than the JunoCam data. That said, I'm especially interested in seeing the JunoCam coverage of Jupiter's north polar region. The north pole will soon be in sunlight which is great and saves me from becoming frustrated by the fact that the north pole will be in darkness when JUICE arrives at Jupiter and will still be in darkness at the end of the mission (there is an inclined phase during JUICE's tour, allowing it to view the polar regions). So we get to see the north pole during summer after all.