This will be where we talk about the data as it arrives over the next 20 months or so.
Just made it a little smoother
Can we expect more images by Friday 11th?
Which areas of Ultima Thule got the highest resolution coverage?
Posts concerning the search for a new target after Ultima Thule moved to the http://www.unmannedspaceflight.com/index.php?showtopic=5368 thread.
New Horizons is in solar conjunction, I think new data will be arriving next week
http://www.planetary.org/multimedia/space-images/spacecraft/dss43-talking-to-new-horizons.html
https://spacenews.com/new-horizons-completes-flyby-of-ultima-thule/
The LORRI field of view in the highest-resolution "CA06" LORRI images is just a bit bigger than the size of the target, so with luck we could get the whole thing. The relatively slow rotation means that we'll cover much the same face as seen in the images already down, though of course from a somewhat different angle.
John
Canberra is listening and talking to New Horizons according to DSN Now.
(Rubs his hands impatiently)
An excellent article was just posted by the NH team about Ultima-Thule :
"Overview of initial results from the reconnaissance flyby of a Kuiper Belt planetesimal: 2014 MU69"
https://arxiv.org/abs/1901.02578
CONGRATULATIONS again to the NH team ftr this incredible feat !
Does anyone know when the next press conference will be or if it has been scheduled?
It's hard to know without seeing the raw images how much noise we have in these views. To me they look noisy (and we were told to expect noisy images), so I'm suspicious of the fine, pixel-scale detail. But on the other hand, the abstract cited above refers to the "mottled appearance", and the team should know whether the amplitude of that fine detail is consistent with noise or not. Or maybe by the "mottling" they mean several-pixel-scale detail? It'll be really interesting to see the closer views.
And also interesting to see higher phase angle views, to break the degeneracy between topography and albedo variations...
The interesting light color at the "neck" might suggest there could be slight movement between the 2 component bodies, and "grinding" of relatively fresh ice in that area...
Tidbit from Alan Stern on Twitter yesterday: "We’re plaiinong an inage release— in 10 days!" (I make that about 23 Jan).
https://twitter.com/AlanStern/status/1084661266159931393
An animation about details. Quality of 4:22 LORRI image is lower, but still.
A slightly more elongated and less round shape of UT from a slightly different perspective ? https://twitter.com/hashtag/UltimaThuleFlyby?src=hash
New movie from 500000 km to 28000 km: http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20190115
Oops! Sorry about that.
John
Wonderful images! Amazing how a slew of pictures at very moderate resolution can still be pretty insightful. I took one of the GIF animations and made an aligned and 'bouncy' version:
My speculation is that the two lobes were never individual objects in the first place, and that the original fast rotation of MU69 -- back when it was newly formed and more prone to deformation -- caused a 'blob' to begin to separate from the main body due to centripetal forces, which in the end weren't enough for the two components to part completely.
Just a stab in the dark from a layperson!
For example, two bodies could be originally separate and flattened independently as a result of rotation. More data from New Horizons is needed.
Ultima Thule looks like a snowman. A big snowman is a good way to think about formation and properties.
Comets have density about that of handmade snowballs. U-T is probably similar.
Calculating gravitation and centrifugal acceleration will show it is gravitationally bound over the entire surface and so was not formed by stretching a sphere.
The escape velocity is about that of a human thrown snowball. Fall velocities would be similar. At such velocity, a small snowball acreating under gravity will splat. For a large falling snowball, self gravitation will keep the ball in shape. Higher impact velocity would change things, but without large nearby planets to shift orbits, this is unlikely.
The compressive strength ordinary packed snow is sufficient to prevent a 19km and a 14km balls from merging to a much more compact space. It is easy to estimate the contact area.
Modelling the gravitational field shows local down is up to about 30 degrees from surface normal near the neck. This is about the angle of repose of lightly packed snow.
As Stevesilva supposes, the slightly flattened shape of Ultima (and Thule?) - if it is not a low resolution artifact - may be the result of the specificity of the accretion process itself - in one plane, a bit like an accretion disc (?)
I think the wonderful New Horizons team is already working on the interpretations.
New post from Alan: http://pluto.jhuapl.edu/News-Center/PI-Perspectives.php?page=piPerspective_01_17_2019
In addition to data downlink from MU69, some distant observations of the unchosen flyby target in March, and some extra fuel for post 2020 maneuver to a more distant object.
I just played around with the sequence
https://www.youtube.com/watch?v=T_HGXKO9kus
Looking for surface features. Strong Fourier-based processing performed, details are exaggerated if resolved properly.
05:01:47 (better res) vs 6 stacked 04:04
Focused on Ultima:
What would happen when a body the size of one of UT's lobes was spun up if most of its mass was made up of a bunch of spheres a few km's in diameter instead of many smaller pieces? Would it end up hamburger shaped instead of football shaped as it shifted toward equilibrium?
Analysis of Ultima Thule comparing its morphology with those of previously-imaged comets....
https://www.forbes.com/sites/startswithabang/2019/01/21/new-horizons-big-reveal-on-mu69-ultima-thule-is-a-typical-future-comet/#633d1e8431e0
...by astrophysicist author Ethan Siegel.
The current best image (a big improvement over the earlier ones, due to lower noise and higher phase angle) has just been posted:
http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20190124
John
Wow, that is a fantastic image - I have just played with it slightly here by brightening the terminator to show faint features a bit better. Just don't ask me to interpret it! - well, OK, maybe the broader depressions near the terminator of the large lobe look a bit like they are bounded by scalloped scarps retreating due to volatile loss.
Phil
An amazing object!!! And it is becoming more and more fascinating. There are really a lot of these small hollows on almost the entire surface. I can not wait for more detailed pictures. Sadly, we'll never see the reverse side...
This faint white ring is... interesting:
Amazing new image! It really does look more like the smaller lobe has massive impact on it (like Phobos' Stickney crater) or Damodar on Mathilde.....
This confirms the closest approach images were captured successfully? Big sigh of relief!
Any idea where exactly the rotation pole is? I'm assuming near the centre of mass, on the right side of the circle Gladstoner added.
I get the impression that its possibly evidence of been put together like a hailstone accretion and the lines and lumpy appearance might be an artifact of that. https://upload.wikimedia.org/wikipedia/commons/9/94/Granizo.jpg Could also be the reason for the 'hamburger' shape if the individual lobe were slowly rotating during the accretion process before coming together.
Yeah that's my thought too, kinda like a kid with a snowball that keeps packing more snowballs onto it. Maybe the Thule lobe is just large enough to hold itself together, while the smaller objects just slumped.
It's a jaw-dropping image: congratulations to the NH science team.
Here's a colorized version, purely for aesthetic purposes:
One side of that dim ring on Ultima appears to be made up of two slightly separated arcs, on the side nearest Thule. The ring looks lopsided at first glance, but appears to have bilateral symmetry, on either side of a line running across it diagonally toward the dark cleft on one side of the 'neck' region.
The news article comments on differences in the geologic character of the two lobes of Ultima Thule. Whether the suspected difference is compositional or textural this could imply the lobes developed separately. If so then when Ultima and Thule came together there would potentially have been a few scrapes, bounces and heat as linear and angular momentum was sorted out. In this respect the light ring Gladstoner refers to seems to fit the crater in the smaller lobe. Bit of a stretch but not beyond the bounds of possibility.
The two best views of UT thus far (courtesy of LORRI and MVIC):
If we think back to the fact that they're more hamburgers than spheres that ring might be circumpolar (well, the pre-merger rotational pole) and Ultima might've looked like Saturn's moon Atlas or Pan before getting a remora.
The sparse cratering is intriguing. So far, the bodies don’t seem to be crater-saturated as one would expect for small, primitive bodies. Either they were resurfaced, or we are seeing a barely altered primordial surface. I don’t know of any other body in the solar system where this is close to being the case. Of course, forthcoming images will provide more details.
Plus, the crater size distribution seems to be one large depression on Thule and a few pits near the limit of resolution. So far, there appears to be a dearth of intermediate sizes. It’ll be interesting to find out what this says — if anything— about object distribution in this part of the solar system, assuming these are impact craters.
Also, there seem to be a number of concave scarps that are outward facing. Could these be slumping that occurred on an earlier, rapidly-rotating Ultima?
Very nice work!
Some "scientific artists" of the past had anticipated the shape of that new type of solar system object. Really remarkable!
At first sight, I would bet that the density of Thule is higher than the density of the external blanket of Ultima since Ultima seems to have been more distorted by the relatively soft impact wheras Thule seems more uniform (or less distorted).
Can the gravitational interactions between the two parts in the rotation process engender landslides or resurfacing events erasing some craters?
I would think that you just don't have that much out that far...it unlikely to be any sort of resurfacing...how would that even happen that far out on a dead object like this?? Accretion over millions of years??
It seems to me that an impact as large as the one on Thule would create enough momentum to separate the lobes, at least temporarily. Could the "ring" be a previous "attachment point"?
Small round pits are not necessarily impact craters. They are best seen at the terminator, but they seem to cover large surfaces - they appear as white dots. They can be "internal" and not "external" origin. They have similar size and lack of size distribution typical of craters. (I'm not talking about a big hole at Thule - it can be a crater, but it does not have to be!)
Some speculation based on the last image two-frame rotating image...
In the rotational image it seems as if there was not one, but two rings of bright material: the central one, and another one to the lower left side of the image. If this is a remnant of an ancient contact point between Ultima and Thule, I speculate that one of them was an earlier contact point and a later impact made Thule roll over Ultima creating the second ring. The exact place where the rolling happened could be the bright patch of material that is where both possible rings find each other. Since the lower left area apparently has two small craters / sinkholes, it would be the most ancient area.
In Thule there appears to be two different types of terrain. Right on the top we see some possible cratering, as well as on the right side of the depression / crater. But the central left side of the depression / crater appears smooth to a certain degree. This may be due to lightning conditions, but I think that an impact has enough kinetic energy as to melt partially the material in Thule and make it flow over older terrain. With such a low gravity, most of the splash would be lost but the melting could flow that way. The "melting" also seems to hide a bright line, that could be the ancient contact point between Ultima and Thule: it appears to be an arc of roughly the same size of the other rings in the current contact area and in Ultima. If so, stretching the hypothesis the V in Thule could correspond to the marking of the rolling: in Ultima we see two well-defined arcs touching, and the V in Thule would be the remnant of one of the sides of the touching arc. Also, the crater / depression has no clean border which could be explained by the melting hypothesis.
So the story of these bodies, according to these speculations, would be:
1. Formation of both bodies and for some unknown mechanism they eventually enter in contact. Original contact point is the central circle on Ultima.
2. Some moderate impact causes Thule to roll over Ultima, possibly from a not strong contact equilibrium position. This creates a second neck, the lower-left circle that seems more visible in the rotation image.
3. A bigger impact creates the crater / depression seen in Thule, splitting the contact binary and causing both bodies to change rotation axis. Eventually both bodies came into contact again, in the position we see nowadays. Impact creates enough cynetic energy as to partially melt the surface of the bodies, causing the flows we see and partially erasing the original contact rings in Thule, as well as melting the crater borders. Ejecta orbits the plane of the impact until collisioning with both bodies, littering the craters we see near the border of both bodies. Since ejecta impactors are small, melting is on a smaller scale and don't cause flows.
Against these hypothesis: there appears to be some sort of flow on Ultima, or at least similarities in the surface features, yet the rings are dimmed but not erased. This could mean that the flow is not such, but the rain of fine debris from the impact. The original impactor would then be the source of most impact craters we see in the border: we can see in the high-resolution image at least a couple of craters of a similar size in the (2) ancient neck, so at least from current data it seems that craters have a clear distribution over both surfaces.
As for the mechanism of making both bodies end up contacting, the only idea that comes into my mind is that since both bodies are fairly irregular in shape, the micro-gravity field should be far from homogeneous causing losses over time as mutual rotations cause shifts in the gravity field, so orbit would degrade over time. But I have no expertise in orbital mechanics, so I don't know if I just said something stupid here.
Exciting!
Here's a version with some colours plugged in from a reprocessed colour image:
As for the mechanism bringing the bodies back together after a major impact, tidal dissipation immediately comes to mind. If the impact energy was enough to make one body at least partially plastic the dissipation would be greatly increased.
However explicitly calculating the effect on two highly irregular (and possibly inhomogenous) rotating bodies in probably very eccentric orbits would be quite challenging. Qualitatively I would guess that the tidal effects would first slow down rotation of both bodies until they became tidally locked, and probably simultaneously decrease eccentricity of the orbits. Once tidal rotational lock is reached any further dissipation would very slowly bring the bodies together.
Of course they could also have re-collided physically long before this. It all depends on the orbits.
An attempt to add colors ...
https://flic.kr/p/23PsZrT
My attempt to improve the image.
Not the best way to do such things when you have no raw image, but anyway
Following on from discussions about the surface geology, some of the shapes seem to be somewhat reminiscent of 'patterned ground' - polygonal structures caused by freeze/thaw and subsequent differentiation of surface material. I'm not sure if UT has enough of an eccentric orbit to cause these processes, but it seems a possibility.
I'm assuming the raw MVIC data downlinked thus far hasn't been thrown up onto the PDS or any other place just yet?
re: resurfacing, we're certainly looking at a world where geology doesn't apply in the usual sense, but there are still mechanisms at this scale that can blank the surface:
• The shaking that occurs with a straight-on impact could cause material to flow down slopes.
• An impact could shower the surface with material causing a new surface to overlie the old one.
• Porous portions of the body could collapse inward to a new configuration at higher density.
• Electrostatic accumulation of fine-grained material burying the old surface.
More?
Another mechanism comes to my mind for the white lines we see. If these bodies are made of lesser balls of aggregated material, which originally may have clumped before being added to Última and Thule, they would have boundaries. Any energetic impact that could have partially melted the surrounding material of the impact area could cause a melting, which would naturally flow through these discrete boundaries filling them up and causing contrast of materials.
As a result, even if there was a full melting of the clump surface, boundary would still differentiate. And the big circle in Última seems exactly that: melted surface which slightly seems a done with a surrounding ring, but the flowing material escapes this boundary - this seems apparent on the right side.
Against this, is where would be the impact crater causing any such melting. Thule has a crater, but Ultima seems devoid of any such originator in the area.
During Rosetta's 67/P mission, there have been lots of speculations about cometesimals as building blocks. https://www.aanda.org/articles/aa/pdf/2016/08/aa26968-15.pdf appears to contain some of the according discussion, especially subsection 4.3 about their hierarchical agglomeration.
The paper is referencing a paper about simulations of this mechanism. Here an excerpt of https://ui.adsabs.harvard.edu/#abs/1997Icar..127..290W/abstract:
Ultima resembles a bit Atlas too, which would imply it accreted within a ring of particles
This model assumes gravitational instabilities formed 1 km planeteseimals which them accreted leftover cm-sized pebbles. It includes a period when similar sized planetesimals accrete each other:
Forming the Cold Classical Kuiper Belt in a Light Disk
http://adsabs.harvard.edu/abs/2016ApJ...818..175S
There are also some LPSC abstracts discussing formation mchanisms:
https://www.hou.usra.edu/meetings/lpsc2019/pdf/2809.pdf
https://www.hou.usra.edu/meetings/lpsc2019/pdf/3044.pdf
Interpolated animation derived from CA04 LORRI and CA06 MVIC frames
https://arxiv.org/abs/1902.00997
Will our estimate of the rotation rate ever become good enough to look back at the occultation results from last year and work out exactly how many rotations have happened since?
New Horizons' Evocative Farewell Glance at Ultima Thule
Images Confirm the Kuiper Belt Object's Highly Unusual, Flatter Shape
http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20190208
I usually read with fascination but don't contribute for fear of denting the signal to noise ratio. However, it seems worth noting that my very un-expert brain immediately drew a connection between the weird shape of Ultima Thule and the weird shape of Omuamua. A flat, sail like, shape has been put forwards as an explanation for Omuamua's light curve I believe, and now it seems we have proof that nature can indeed craft such a flattened shape. Is it rediculous to suggest that the interstellar object could have formed in the same region of it's original solar system that Ultima Thule occupies in ours, and the two formed along approximately parallel lines under similar forces - acting in a bizarrely
pro pancake shape fashion?
Absolutely bizarre! A bit like the tiny moons of Saturn... but no rings anywhere nearby.
At the very least, this is good confirmation of two separate bodies being formed.
I realigned the MU69 departure movie on MU69 itself to make an occultation fence. It looks like the small lobe is relatively well-constrained by stellar occultations. The larger lobe is a little more difficult to pin down, with fewer stars along the occulation path.
Bravo for the occultation fence photo. The movie of it was too hard to follow for me.
Could it be that the problems of dissipating momentum, and the odd, flattened shapes of Ultima and Thule could be related? Could the momentum have been dissipated when the two objects encountered each other in space, in the process of pulling each other into the flattened shapes we observe today?
http://www.unmannedspaceflight.com/index.php?showtopic=8437&st=200&p=243031&#entry243031 on the press conference remind me that it was predicted that CA06 would be the potentially highest resolution images. These "crescent" images are CA07 and I see CA01 and CA04 in thehttp://pluto.jhuapl.edu/soc/UltimaThule-Encounter/. Still more coming!
Alan Stern tweeted, new pics tomorrow .
Sharpest view of Ultima Thule: http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20190222
"...The most detailed images of Ultima Thule -- obtained just minutes before the spacecraft's closest approach at 12:33 a.m. EST on Jan. 1 -- have a resolution of about 110 feet (33 meters) per pixel..."
"... The higher resolution brings out a many surface features that weren't readily apparent in earlier images. Among them are several bright, enigmatic, roughly circular patches of terrain. In addition, many small, dark pits near the terminator (the boundary between the sunlit and dark sides of the body) are better resolved. "Whether these features are craters produced by impactors, sublimation pits, collapse pits, or something entirely different, is being debated in our science team," said John Spencer, deputy project scientist from SwRI."
Am I the only one that thinks that NH missed MU69 at the closest distance ?
Amazing new views!
A bit disappointing how grainy the images are, but I'm sure a few image processors will pretty them up in no time! Absolutely astonished that they were able to capture the entirety of MU69 in the frame, considering how fast everything was going, and the margin of error! What a feat of engineering and mathematics this is! Congrats to all involved!
The noise in the pictures is the effect of adding up the huge speed of the ship during the flight, the very dark surface of the small object and the poor lighting due to the great distance from the Sun. Under these conditions - really great photos!!! Congratulations for the precision of framing!
I think that this noise will leave us forever with many unsolved questions about UT.
I am thinking that the posted image is just a placeholder for better processing to come. In just a minute or 2 in PS I got this:
Here is my colorized version of the latest and sharpest LORRI picture of Ultima Thule. Colors from MVIC low resolution picture:
https://www.flickr.com/photos/thomasappere/33304280358/sizes/o/
I think a lot of us were expecting to see more detail, of course MU69 does not have the topography Pluto does. Also the pictures of Manhattan that were posted by people did really help much to give an accurate expectation. There are no Freeways or Skyscapers.
[post removed] just got confused with LORRI images archive, sorry.
Raw pictures posted: http://pluto.jhuapl.edu/soc/UltimaThule-Encounter/
I wonder that, maybe however, the NH team is hiding "something special" for the March conference...???
it's just my little hope
Well, there's been no public release yet of the colour version of the http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20190124 from Jan 1st...
This animation helps to better understand the shape
Recent talk by Alan Stern:
https://www.youtube.com/watch?v=vCr_bkzgFT0&feature=youtu.be&t=3714
Lots of Ultima Thule talks tomorrow at the LPSC:
https://www.hou.usra.edu/meetings/lpsc2019/pdf/lpsc2019_program.htm#sess103
To the extent that the spectral responses of the two cameras are different, you could create a crude 2-false-colour image from those frames. You'd need to warp one frame to align them better, though.
I was in that session at LPSC - they are working on shape and stereo but more to do for a final shape model. Then the images can be merged effectively.
Jeff Moore said they are not convinced the small pits are impact craters, and suggest some may be drainage depressions leading into sub-surface voids. Not sure I agree, but a size distribution plot would be a useful thing to help with that problem.
Phil
Livestream here at 1 ET
https://livestream.com/viewnow/lpsc2019
unmannedspaceflight.com was just mentioned at the press conference
Press conference material is up on NH website
http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20190318
with slides here:
http://pluto.jhuapl.edu/News-Center/Press-Conferences/index.php?page=2019-03-18
more reporting coming out, this from https://www.sciencenews.org/article/new-horizons-mu69-ultima-thule-frankenworld?tgt=nr
Initial results from the New Horizons exploration of 2014 MU69, a small Kuiper Belt object
https://science.sciencemag.org/content/364/6441/eaaw9771
Outstanding.
In addition to name-checking the forum & highlighting Roman's work, an UMSF moderator is one of the coauthors of this paper.
Though this issue is moot now, the article only says "following a significant backlash", so I don't think the final name and the New Horizons team nickname are really connected in any way. The headline writers are just looking for clicks by putting the two together.
I do wonder if the sports equipment transport company or the air base in Greenland ever got a complaint...
If the new name is all right with Alan, it's certainly OK with me. I do wonder whether NASA will also be giving new names to the two individual lobes?
The IAU is the authority for all naming conventions, including classes of features. What might get interesting is what exactly the lobes would be classified as geologically, or if they'll come up with a new category for them.
This may have already happened with comets since 67P C-G, 103/P Hartley, and Borrely apparently consist of lobes as well, though the mechanism by which they arose may be different.
More on the naming process that was followed in this instance
http://www.spacedaily.com/reports/NASA_renames_faraway_ice_world_Arrokoth_after_backlash_999.html
IAU had the final say, but it seems the change was initiated by the NH team itself, then passed to NASA, who then consulted the Powhatan tribal elders.
One problem with the name "Ultima" was that it was rather... ultimate. Even for NH, with luck Arrokoth won't be its farthest encounter and "Penultima" might've been more appropriate.
(PS - time to change the name of this thread?)
Thread title amended as requested.
Arrokoth Flyby
(3D visualization)
I can't stop rewatching that. It's just peacefully tumbling out there as NH flies by it.
Arrokoth Synthetic Stereo Pair (Cross-Eyed Version)
This is really wonderful, especially since there were no actual "half-phase" images, (the lack of illumination combined with flyby speed made it impossible, I assume)?
Arrokoth Approach.
About 230 images of Arrokoth were aligned, stacked, deconvolved, resized and de-rotated to create this 'ping-pong' animation.
The animation covers 13 hours of observations.
That is fascinating, Roman. Well done!
Phil
We already know what the other side looks like, at least in terms of shape, from the observations of blocking starlight during the flyby.
See here: http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20190208
On the other hand, AI is not the genius your post suggests it is, it can't tell us anything about the actual appearance of the other side in the absence of actual data. The animation goes so fast that it's a bit hard to tell what we are seeing, but this view does not include the other side, just the side we can see at close approach from a different angle.
Phil
I noticed that the official names of the surface features on Arrokoth have finally appeared on the IAU website: https://planetarynames.wr.usgs.gov/Page/ARROKOTH/target
(and also Bennu: https://planetarynames.wr.usgs.gov/Page/BENNU/target
and Ryugu: https://planetarynames.wr.usgs.gov/Page/RYUGU/target )
New paper on Arrokoth's discovery by Buie et al.:
The following article is Open access
The New Horizons Extended Mission Target: Arrokoth Search and Discovery
https://iopscience.iop.org/article/10.3847/PSJ/ad676d?fbclid=IwY2xjawFQ-cVleHRuA2FlbQIxMAABHasyhG_fg-0X46K0a5_iyNC8qbI_tzGlQbiR2KAEAZ7xT4vuNgfPNw3YwA_aem_Vgey3rQR-hyyyY8sOaWKqA
List of citizen ice hunters at the end there.
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