No, but I don't know what Bill was talking about. Sure, one would expect some relief from clouds, and sure, stereo could see that in theory.

Don't even get me started about shape from shading.

On a three-axis stabilized spacecraft, any camera can do this by using a long exposure time. It's only because Juno is a spinner that it becomes so difficult. And the SRU is terribly constrained as a general-purpose imager. No reflection on it, it's a star camera and was never intended for this application.

Sure, subject to the caveats that every Junocam "image" is a sequence of framelets taken at slightly different times from slightly different locations, the clouds themselves are moving dynamically, and the orientation of epipolar lines is complex and variable across the FOV. See Gerald's slides for a taste of all the complexities involved and all the work left to do.

I'm don't think it's happening here, but I've seen lots of "stereo" images where there was some factor that wasn't considered, and people were just deluding themselves into seeing relief.

Does anyone know how the old twitter bot https://twitter.com/dsn_status got its information? It no longer appears to be updating.

https://eyes.jpl.nasa.gov/dsn/data/dsn.xml gets you an XML file with the current DSN status, but this doesn't include the in-lock/out-of-lock and modulation info that dsn_status displayed.

Better unpaywalled link is https://www.esa.int/Science_Exploration/Spa...s_of_Red_Planet

4.3 microns is not quite thermal IR, and there is an CO2 absorption there, so I would guess the 4.3 micron signal is correlated to elevation at least in part.

Seems odd that they didn't show the same FOV between the two wavelengths.

Nice, but my sims show Europa not leaving the FOV so quickly. Are you using a C kernel like juno_sc_prl_220928_221105_jm0450a_v01? There's a 4.5 degree offset from grav orientation for this pass.

Correct. Strictly speaking, there's no such thing as an active radiometer. Anything that has active and radiometer in the name is probably some kind of hybrid radar/radiometer, but MWR is not that, it's receive-only.

https://dataverse.jpl.nasa.gov/file.xhtml?f...amp;version=1.0 is sort of old, but the full Springer paper is paywalled, alas.

Sorry, yes, obviously, I meant km/pix. Edited.

Probably. USGS coverage maps claim 6 km/pix over that area and we should get 2-4 km/pix. But we've found that the coverage maps are often optimistic about resolution, as some of it is motion-blurred or otherwise not great. On the other hand, it's a fast flyby and I don't want to overpromise anything.

Junocam will take four RGB images on one-minute intervals starting at around terminator crossing (roughly 09:37:30 UT), using the same method used for the Ganymede imaging last year. I'm not sure when we can expect the data to show up, hopefully before that weekend but no guarantees.

I see very little evidence that Chinese plans have influenced NASA plans in any way. The Chinese have also said they intend to return martian samples by 2031 (see https://www.space.com/china-return-mars-samples-earth-2031 ) but that has had no effect on NASA/ESA's MSR plans.

If you look at the entire history of Discovery and NF mission selections, I'm not sure what conclusions you could draw. IMHO a lot of the selection seems to be done on the basis of non-scientific considerations (cost, cost phasing, mission schedule flexibility, real or perceived technical maturity, NASA center assignment, etc.) To think it's 100% about the science is naive. I'm not accusing anyone here of naivety but it's worth pointing out.

I'm not sure what this discussion is doing under Mars&Missions/Past and Future in the first place. Agreed the Venus-specific stuff could go elsewhere.

Fair enough, but that is a back-rationalization, not an explanation of how the two missions were selected. FWIW, I see no evidence that ESA considered synergy with the NASA missions at all. The selections were likely pure coincidence (an ANTZ/BUG'S LIFE situation, if you will.)

We seem to have gone from a perception that Magellan did everything there was to be done (common in the 90s and 00s) to a perception that Magellan data was so awful that redoing Magellan with somewhat higher resolution (Envision claims 30 m/pxl globally and 10 m/pxl in selected regions, Magellan was nominally 75 m/pxl but probably not that good globally) is absolutely revolutionary. It will be interesting to see a new generation of scientists confused by SAR data

I'm sure one can find lengthy descriptions of why Envision SAR will be so much better. Maybe they're even true.

Admittedly, I would not have predicted that outcome either. And ESA's thought process in that case is a mystery to me.

It's not like anyone asked me to participate in an Io proposal, so it makes no difference how I feel about it. At various times I have had to do a ton of work to support proposals that seemed like long shots to me. Most of the time I've been right, but I've been wrong just often enough to make it impossible to write anything off.

Of course you're right scientifically; I should have said "will be viewed as redundant" rather than "is redundant".

Politically, I think it's very unlikely that an Io mission will get selected when two other big missions will be active in the jovian system; the Io community is just not big enough to make that happen.

But this is just my own take, obviously.

Hard to say what EC will ultimately do; they have understandably hunkered down to a very Europa-centric plan but one could hope that might loosen in an extended mission.

Thank goodness, because if they had left it on some group(s) would have insisted on proposing it, despite the IMHO essentially zero chance that another Venus mission would be selected at this point. And I hate to see people bang their heads against a wall like that, having done it myself more than once


We can't talk about Endurance-A here, but the desire of the lunar community to not spend SMD money while moving the goalposts on the original fairly simple SPA sample return mission is what I was talking about when I said lunar missions were unlikely to be selected as part of an NF AO in the current environment.
https://www.hou.usra.edu/meetings/leag2022/pdf/5031.pdf

FWIW, if I was writing the NF AO I wouldn't allow any lunar missions in the first place.

I'd be surprised if advocates of a Saturn probe don't have answers to those objections, valid or otherwise.
See slide 14 in https://ntrs.nasa.gov/api/citations/2016000...20160009334.pdf though it is at best heuristic

Yes, that and overall mission duration.

Fair enough (I can't speak to the similarity of instrumentation) but it's a long way to go for such a short period of data-taking, and missions that take all their data in a short period without any do-overs are always going to be perceived (rightly IMHO) as more risky.

It seems to me that, after Dragonfly, another mission to Saturn is unlikely to get picked next regardless of how worthy it is.

I think history would support the contention that there is not a large correlation between decadals and which missions are actually selected.

My take, FWIW: the lunar missions are DOA due to confusion with the HSF program if nothing else. Enceladus and Saturn will be judged too risky/immature. Io is too redundant with the other upcoming jovian missions.

Assuming they even issue the AO due to budget issues.

Forgive my cynicism (if that's what you want to call it) -- I've been in the business for a long time.

Not needed.

https://mars.nasa.gov/mars2020/spacecraft/r...-On-The-Surface

Unless you deliberately blurred the images, this kind of simulation always massively overestimates how many details you would really be able to see. Just FYI.

Yes, all of our "digital CDS" CCD systems going back to the original MS98 MARCI have had this, it seems to be intrinsic to the CCD output. The DC offset has to be compensated for if you use sqroot companding. You can perhaps find indications of this if you look at papers, the PDS docs for MSL and M2020, etc. hard enough (or not.)



Yes, and this image shows that it is unchanged since pre-launch.


There's a mode like that for MSL/M2020 though AFAIK nobody has ever used it. There's no such mode for Junocam, which uses a piecewise-linear compander instead of a table lookup compander to save parts and logic in the JDEA.

The reconstruction method you describe might work for a smoothly-lit bland object. The TV system on Mariner 6/7 had a "digital video" stream that consisted of truncated samples like these, but the reconstruction method had problems and the whole concept was generally thought to be a bad idea and was never used again IIRC. https://nssdc.gsfc.nasa.gov/nmc/experiment/...id=1969-030A-01

Or maybe even a little better. 0.6 microns = 600 nm is in the visible, of course.

JWST's IFOV is about 0.031 arcsec (NIRCAM), compared to HST ACS WFC of 0.05 arcsec, 0.028 arcsec for the HRC (no longer working), and 0.04 arcsec for WFC3 STIS.

Though I'm not sure how JWST is defining their resolution with respect to the PSF at any given wavelength.

Of course not. That's sort of like expecting a Coke machine to reload itself if you just leave new cans next to it on the floor, isn't it?

"Mars 2020 Rover Adaptive Caching Assembly: Caching Martian Samples for Potential Earth Return" https://trs.jpl.nasa.gov/handle/2014/52365

This was companded with the "linear 1" settings, I wanted to see if there had been any significant changes in the black level of the sensor.

[IIRC linear 1 maps 0-255 directly, 256-511 divide by 2, and clamps higher values to 255, because of idiosyncrasies in the logic implementation. ]