Looks like hydrated clay to me Looks a lot like Triton's color and less like pluto.

Will love to see what data comes back.

That looks like an image generated from a 3D model, rather than a photograph.

You could be right, but I'm not sure really. If this is a 3D model, I would have expected them to present it in a different way. At the resolution it's being shown, he could have used on of the real images instead, so why go trough the trouble of creating a 3D asset at this point, especially since they're sure yet about the topology? Considering this was not shown at the briefing, i'm completely puzzled bu the origin and purpose of this image.

The fact it lacks the albedo markings makes it pretty clear. It was probably just meant to show that they have a 3D model, which would be easy to create once you have the stereo pair.

Here's a cross-eyed version of the flicker gif released today, no further processing:
Click to view attachment

I tweeted this at Alan Stern but I imagine that he's getting so much spam that I'm going to repeat the question here in the off chance that he gets some time to read it and give a reply:

@AlanStern Amazing work by the whole team. I'm curious why thumbnails of CAO6 weren't prioritized among some of the first data? Couldn't those be binned down to more or less trivial amounts of data by the spacecraft and still give you an idea of what to expect? Thanks!

Since I'm in long form - GIF compression with white and black only, say 4x4 each, then maybe even reduce that to a 4-bit value that simply represents the number of pixels that ended up white(and if you are really trying to conserve bits, then gzip the whole 4-bit series as a C struct/array with the sequence identifiers as the keys, I imagine it would compress to <300 bits or something ridiculous like that) - all 3 of these options are practically nothing even at <1000bps, and the binning process sounds like a good deal less work than the process described during today's press conference to try to infer if and in which sequence there is anything useful based on refining trajectory elements, so I assume that there's a very good reason for not using thumbnails and I'm very interested to learn what it is.

Odd, but I'd received the impression that an image with about twice the resolution of that shown yesterday was likely to be seen today.

Looking at the above 3d image, it appears as though the possible large depression on the 'Thule' lobe could be unusually deep and steep-sided.

According to Emily, we were supposed to get another 140 m/pixel image overnight, which would be similar resolution to the higher-res one from yesterday.

It helps to consider that the two lobes of Ultima Thule are, roughly, the size of the nucleus of Halley's Comet.
Which raises the possibility that it could also be a comet 67P style sublimation pit.

But that triggers some really interesting questions about the scale of KBO building blocks-

Comet 67P shows evidence that is formed out of ~10 foot/3 meter units, "dino-eggs" (aka "accretting pebbles").


UT is about 10x the diameter of comet 67P, so, roughly, the "pits" on UT are around the size of 67P's lobes.

One big question is whether is UT is composed of 67P sized chunks, or from 10m "pebbles", or a mix of both.

Another big question is, which follows from observing the "diamond in the sky" rubble pile asteroids Bennu and Ryugu, is, what is causing the lobes of Ultime Thule to hold their shape? Are Ultima and Thule just "pebble piles" which hold their shapes because they have acquired a tholin surface skin?

As I understand it, the Milky Way (our galaxy) is inclined at about 60 degrees to the Plane of the Ecliptic in which Pluto, Ultima Thule and New Horizons currently reside.

Right but the two planes intersect, and at that intersection, in the crowded star fields of the galactic centre, it's difficult to detect solar system bodies amidst the glitter of lights.

Quite possible. An impact that large, in proportion to the size of Thule, might have shattered it. Is much sublimation expected at 44 AU from the Sun?

And we need to be thinking in terms of dynamics of materials at near absolute zero. (That react differently than materials heated by high-velocity impacts, radiation, etc.) Maybe even a "low velocity" impact could add significant heat relative to those low ambient temperatures, and cause structural as well as chemical changes.

Likewise, could heating from radioactive decay of things like 26Al be very localized within those bodies -- causing such things as outgassing from certain areas and not others?

Yep, quick double-check shows that common ices are still volatile way past 44 AU.

N2 sublimation- 22 Kelvin/160AU
CO sublimation- 25 Kelvin /120 AU
CH4 sublimation- 31 Kelvin / 80 AU

Using Cometary Activity to Trace the Physical and Chemical Evolution of Cometary Nuclei

Not having to have the ground in the loop to decide what to send down would be one reason. Especially when you're six light-hours away.

No need for the ground to be in the loop for the operation I described. What I described is a simple sequence of software that the spacecraft can run to produce a data product that could be less than 300 bits which would tell them if, and in exactly which images the highest resolution pass captured UT. It's not unprecedented, this has been a common practice during the opening days and hours of multiple recent missions and encounters(thumbnails in general that is, not the extra reductions I described to further minimize the size of the useful dataset in the case of this particular mission.)

Which missions are those?

Maybe they just didn't think of it or they couldn't make it fit in their FSW. There's a general bias to minimize work done on the space side even if work on the ground side is 10x harder.

We use thumbnails on MSL, obviously, but usually not to pick and choose what to send down once we see the thumbnails. Sometimes, not often.

MSL is the one that comes to mind instantly, however I've seen the same practice being used on Cassini for encounters, ROSETTA did it, and I just assume it's being/was used for insight, since phoenix did the same. Perhaps the piece that I'm missing is just your third sentence about 10x ground. Thanks for that insight.

Did Cassini use thumbnails? Maybe, I wasn't aware it did.

NH probably wasn't designed with a flyby of a small body with such uncertain centering in mind, I don't think they had so much of a problem at Pluto (but I could be mistaken.)

FWIW, I argued long and hard that thumbnails for MSL Mastcam were not worth implementing. In hindsight I was wrong, but the use case of ground-in-the-loop selective transmission doesn't end up getting used that often, and we had to work fairly hard to get the thumbnail products small enough to be cheaply downlinked. They are mostly useful just to show that a sequence executed as designed, but that's fairly expensive for what amounts to debugging messages (though one can amuse oneself by building mosaics of thumbnails while waiting for the full products, etc.)

You may have answered your own question. Req. We don't know how the flight software of NH is configured, so it's possible that adding such a feature would incur operational risks that we with our limited (as in zero) understanding of the FSW do not know. Additionally, time and labor are limited resources, and presumably something like this has gotta rank pretty low on the priority list.

EDIT: I see that Mike has answered you as well.

Moving on...

Emily mentioned that histogram data are included in the image metadata that is being downloaded before the rest of the images are -- which should be enough to determine which frames contain UT image content, and to help prioritize them.

ADMIN NOTE: Since the encounter phase and frequent press briefings are nearly over we'll be starting a new thread to discuss the flyby results as they come in over the next 20 months, similar to what was done after Pluto.

This thread will be closed in the near future.

Just to be clear, the only reason I asked the question in the first place is because during today's press conference, Alan said this:

"Yeah, we don't know that yet Ken. In order to get that, we're going to have to analyze the images that we have in a little bit more detail. But more importantly, we have to get down some engineering data that tells us about the pointing, and we have to get our next trajectory reconstruction of the first post-flyby, and to get all of those steps is going to require a couple of weeks of work after we get out of the solar conjunction that I was talking about, and at that point we will be able to calculate where in that long train of hundreds of images we will find Ultima, and then place commands in a command load for February to download only those that contain the targets." This answer seems to explicitly state that they will be doing this selection "in the loop" by Mike's above definition, regardless of the method that they use to identify the sequence numbers to grab first.

Thanks again Mike for the insight, I love learning about the details of MSL, or whatever. I really appreciate all of your responses.

I'm not trying to act like I know better, this team has my complete benefit of the doubt, I just want to learn why they didn't just write/QA some quite simple code(especially compared with the other things they have to write/QA for this mission) and then download 300-10,000 bits of data to know right now, so that they can augment their team planning, and as an extremely distant second, give a better answer to the easily predictable question that Alan answered above during their (second)15 minutes("You said you might not get the best images. Did you?")

Re. helping to observe and measure occultations by Kuiper Belt Objects:

A major omission from my previous links:

The RECON project:
http://tnorecon.net/about-us/about-the-project/

RECON is devoted to observing stellar occultations by "Trans-Neptunian Objects" (TNOs) -- i.e., bodies whose semi-major orbital axis is greater than the semi-major orbital radius of Neptune -- and which include the KBOs.

Here is a quote from their website:
RECON — the Research and Education Collaborative Occultation Network — will involve students, teachers, amateur astronomers, and interested community members in a citizen science astronomy research project to study the outer solar system. We are providing telescopes, camera equipment, and training to over 40 schools and education centers across the Western United States so students and teachers from these communities can help us determine the sizes of objects out past Neptune through occultation measurements. To learn more about RECON, visit http://tnorecon.net/

Funded by the National Science Foundation, RECON is run by planetary scientists Marc Buie from Southwest Research Institute and John Keller from California Polytechnic State University.

You can sign up to join their project or request more information at
https://docs.google.com/forms/d/e/1FAIpQLSc...6b7X9g/viewform

A few points-

- One additional big reason why we can't get down the highest-resolution images earlier, is that they are stored on the second solid-state data recorder (SSR2), which we can only access when we power up the backup computer, Given our tight power budget and other complexities (e.g. additional housekeeping data are generated and need to be downlinked when the backup computer is is powered up), we have to wait a while to power up that computer again to get at the SSR2 data.

- The command loads, which each cover 2-3 weeks of spacecraft activities, are developed over a cycle that starts well over a month before execution. So to downlink jailbars and use the m to determine which images to send down wouldn't be any faster than what we're currently planning.

- Yes, we get down histograms for each LORRI image, but they are quantized in a way that means that a faint target like Ultima doesn't show up in the them, in the short exposures needed for our highest resolution images. So histograms don't tell us which images contain the target.

- Adding the capability to generate and downlink thumbnails, like any flight software change, would take months to develop and test to ensure it was bulletproof. Given our small team, it wouldn't be a good use of resources.

- Like Alan said, New Horizons is a mission of delayed gratification. Patience is a key requirement.

- The best illustration of the quality of the best images we hope to get is the Phobos-based simulation that I showed on NYE, which includes the actual expected smear and noise levels. The Manhattan image is hot intended to be a high-fidelity simulation.

John

any targets after Ultima Thule?

Thank very much, John, and congratulations!

Second that - thanks John.

We're like a hoard of excitable kids who just want the party bag, with (for the most part) little conception of the effort and work involved in organising the party.

I learned to be patient from the Galileo mission.

Thanks for taking the time to weigh-in with us John during what must be the week of a lifetime for you. You guys and gals are amazing!

I always keep handy the January 1977 National Geographic issue that was my first major source of results the Viking mission, six months after Viking 1 landed. To paraphrase Bane, "I was born in patience, molded by it. I didn't see quick results until I was already a man."

Thanks enormously to the whole team and everyone involved!

Thanks to the entire New Horizons team for this astonishing achievement!

As for the next target, my humble suggestion is: a photo of Earth, surpassing Sagan's Pale Blue Dot shot.

I understand that it entails a level of risk, but capturing such a prospect would be an inspiring legacy if you manage to pull it off. Our planetary survival challenges are very acute and near-term and we humans need all the inspiration we can get asap.

I believe Alan said they will wait until they're sure they will not have any encounters before attempting this; apparently the Sun is still bright enough to damage LORRI in case of accidental pointing (for Voyager's portrait this was not an issue).

I kinda-sorta got the feeling that NH team wants to hold that photo until the 2030s when their Cassini-RTG has nothing better to do.

Which reminds me, as to getting data down- has anybody floated any wild plans for "rose petal" 70 meter class double-dish DSN relay? Put a matched pair of 70 meter radio telescope out Saturn, Uranus or Neptune? Provides 70 meters looking out, 70 meters of data relay back towards earth.

Another encounter would be amazing.

Denoised version of the latest picture of Ultima Thule with starfield and cropped and colored version.

They will use LORRI to look for targets.

Composite image of Ultima Thule.

Looks like a good time & place to start moving the discussion over to the new NH Ultima Thule Encounter Observations & Results topic.

This topic will be closed and archived on 6 Jan. Thanks.

Trying to simulate "true colours" by using red and blue-filtered frames, with a synthetic green channel:

Click to view attachment

There seems to be some colour variation, with bluer areas around the "neck".

They will use LORRI to examine known objects and get light curves and other information.

To find new potential objects to visit next will require getting an extension of the mission approved and getting time on Hubble and terrestrial big scopes to search for objects that they can reach. They will then need to determine the new objects orbit precisely with star occultations---ie a repeat of how they found 214 MU69 and got its orbit.

Actually, according to Alan Stern's post in "KBO encounters" thread, they will use LORRI to search for another targets : )

Yes, at this point in time, our best "eye on the Kuiper belt" is on the spacecraft IN the Kuiper belt;
in an odd way, it's interesting, frustrating, and exciting; all at the same time.

The /possibility/ versus practicality of NH finding its own targets has been the focus of a bit of discussion over the years: speculation kicks up every few years, as necessity prods invention.

As of 2012, HST was a better telescope...



Now, as of 2019 LORRI is functionally better than HST, so you just use the best scope you've got,
at least until JamesWebb is up and running....

I hadn't heard that limitation of LORRI before. Is that due to a memory buffer limitation?

That seems to be more of a practical limit due to the object moving during flybys, a few sources indicate the exposure limit is actually 29.9 seconds-

http://spaceflight101.com/newhorizons/instrument-overview/

IIRC, the optics were optimized to take low-light fly-by pictures of Pluto, trying to stare at a patch of sky and build up an image of KBOs photon-by-photon wasn't in the design specifications.

Great encounter, and now it's time to archive this topic and move the discussion over to NH Ultima Thule Encounter Observations & Results for ongoing discussion as the data comes down for slightly less than the next two years.