2014 MU69 "Ultima Thule" flyby, For discussion of the encounter as it happens Options

[elakdawalla]

It's only 10 days now until the "Core" phase of the 2014 MU69 flyby begins! I thought it was time for a new thread. Carry on discussing distant observations of other KBO worlds in the KBO encounters thread, and use this one for MU69 until after the departure phase is officially over on 8 January.

I'll be posting a "What to Expect" article next week.

[Guest_Steve5304_*]

How longafter flyby will we get the first image or hint of success?

[Explorer1]

Nice overview at the bottom of this post: http://www.planetary.org/blogs/jason-davis...ut-100days.html

Then, there won't be much to do but wait and hope that things go according to plan. Around 10:00 a.m. EST on Jan. 1, the team expects to get a health and safety report from New Horizons letting them know it survived the encounter. The first up-close images of Ultima Thule are expected to arrive on Earth between 6:00 and 8:00 p.m. EST Jan. 1 (22:00 on Jan. 1 and 00:00 on Jan. 2 UTC), a NASA spokesperson said.

[nprev]

One thing I'm curious about is the anticipated total data acquisition as well as the time that will be required to downlink it at this greater distance. Obviously there won't be nearly as much data as there was from Pluto just because UT is pretty tiny and the near encounter hi-res phase will thus be exceedingly brief, but as with the Pluto encounter I wonder if they're gonna have an expected recorder space used message as part of the survival confirmation message.

[Alan Stern]

On thing I'm curious about is the anticipated total data acquisition as well as the time that will be required to downlink it at this greater distance. Obviously there won't be nearly as much data as there was from Pluto just because UT is pretty tiny and the near encounter hi-res phase will thus be exceedingly brief, but as with the Pluto encounter I wonder if they're gonna have an expected recorder space used message as part of the survival confirmation message.

Actually the total data volume taken and stored on the recorders is very close to the same as at Pluto; downloading it all will take 20 months. Through Aug-Sep, 2020.

[nprev]

Really! Delighted to be wrong, then. Thank you, Alan!

So there will be an 'expected volume acquired' ping post-flyby as well, then? That was a big moment at Pluto.

[Explorer1]

And we have our first mystery: No light curve!
http://pluto.jhuapl.edu/News-Center/News-A...p?page=20181220

[fredk]

What about a very slow rotation rate? I didn't see anything about what interval the light curve was taken over. Presumably the lightcurve would look flat if the rotation period was significantly longer than the interval the lightcurve was measured over.

I don't know whether there may be expectations that these objects rotate faster than some rate - if so, that could explain the surprize.

[Alan Stern]

What about a very slow rotation rate? I didn't see anything about what interval the light curve was taken over. Presumably the lightcurve would look flat if the rotation period was significantly longer than the interval the lightcurve was measured over.

I don't know whether there may be expectations that these objects rotate faster than some rate - if so, that could explain the surprise.

We have photometry from HST stretching over years and on NH we have been making measurements routinely since September; since later November the SNRs have been quite good. We're looking for periods ranging from ridiculously long (weeks) to ridiculously short (2 hours). Nothing firm yet.

[NMRguy]

Very curious for better resolution on the shape of the object, if it’s a dumbbell, a binary or something more conventional. The occultation data was certainly curious. Best to the amazing NH team in the coming weeks.

[scalbers]

I wonder how much difference there is in the Ultima Thule viewing angles presently from New Horizons and the from Earth perspective informing the occultation data? Consideration of this may help constrain a 3-D shape model (and light curve interpretation). The answer to this is a modest about 11 degree difference, since Emily's article mentions an 11 degree phase angle from NH and we can assume a near zero phase angle from Earth.

http://www.planetary.org/blogs/emily-lakda...tima-thule.html

[Explorer1]

Nice interview on Planetary Radio, some very good details: http://www.planetary.org/multimedia/planet...w-horizons.html

[WTW]

Very good Engineering Colloquia presentation by Marc Buie at Space Telescope Science Institute on the challenges re. discovery and tracking of MU69, and of the encounter itself:

https://webcast.stsci.edu/webcast/detail.xh...47&parent=1

[nprev]

Emily has posted a new article providing links to flyby coverage.

ADMIN NOTE: There will likely be no NASA TV or other NASA media coverage of the event due to the partial government shutdown in the United States at this time. All members are reminded to please read and heed rule 1.2. We have to acknowledge this fact, but we will not discuss or debate it.

The Forum is politics-free, and it will stay that way.

Thanks!

[Explorer1]

Based on the Administrator's recent tweet, and this observation by Keith Cowing, I think there might be something on NASA TV after all. The last few shutdowns had no major space events happening, so my guess is that some arrangement must have been made behind the scenes. We'll see if there is actually a briefing tomorrow...

[nprev]

That would certainly be a most welcome development if it happens; thanks!

In the meantime...UMSF itself is of course a project of The Planetary Society, and we are a part of their education and public outreach efforts. Accordingly, I would encourage all to share any information sources concerning the flyby you can not just here but on your other social media platforms.

Above all else save the success of the flyby itself, it is vitally important that as many people as possible are made aware of this historic event and are afforded the opportunity to witness it. The NH team also should know that they are far from forgotten, and we are all working to spread the word of their work to the world.

It's on. And we, as in each of us, will be a part of making it happen.

GO NEW HORIZONS!!!!

[MahFL]

Not sure if everyone knows but NASA Eyes does have a MU69 flyby preview and a current live view.

https://eyes.nasa.gov/

[JRehling]

Before this flyby takes place, I feel a surge of wonderful curiosity about what we will see. The oldest books about the solar system I read as a kid speculated what the surface of the Moon would look like, and similarly had art depicting imagined landscapes of Mars, Mercury, Venus, Titan, and more. I remember the first Viking photos of Phobos and the supposition (not inaccurate) that asteroids would be similar. Pluto most recently brought us unconstrained surprise.

And now we're seeing yet another new kind of world, and this may not happen many more times (constrain that as you will: this century, in any given person's lifetime, or ever). And we just do not know what we'll see. Will it look like a main belt asteroid, but of nitrogen? Strangely eroded? Shaped by electrostatic forces? A globular cluster of pellets slowly orbiting a center? We do not know!

There'll be some wonderful moments ahead, and it may be that nothing is as fun as the anticipation. Anticipate away!

[nprev]

Undoubtedly. It is a remarkable privilege to be the first of all the humans that ever have lived to see an entirely new type of world for the very first time up close...to say nothing of the fact that KBOs/TNOs were only theoretical concepts until perhaps 40 years ago with the discovery of Chiron.

We already have one mystery: Why no light curve? Unless NH is flying nearly parallel to UT's rotation axis and/or it just doesn't have any significant albedo variations at all that's a real head-scratcher; other KBOs definitely have them.

[MahFL]

2.9m miles now...

[nprev]

BREAKING: Alan Stern now reporting that NASA social media and NASA TV will indeed cover flyby activities.

[dudley]

Perhaps Ultima Thule's lack of a normal light curve means that it's rotating extremely slowly, so slowly that its aspect hasn't changed appreciably since we've had it under observation. Perhaps it's not rotating at all.

Then again, assuming the object is binary in form, perhaps the object's outer-facing hemispheres are lighter in color than those facing each other. This might provide a steady light as it rotates. The light level could be enhanced when less surface area is presented to our view, and detracted from when both lobes are in fuel view.

Judging by the shape model derived from stellar occultation, the two lobes appear to be very close to one another, and to partially overlap, from our point of view.

[fredk]

Check this post from Stern where he addresses slow rotation.

For sure a cancellation between shape and albedo markings could be to blame, but it does seem unlikely.

Another point is that S/N isn't infinite, so all they can say is that the lightcurve is consistent with flat to some % level, and we don't know what that level is (of course it's decreasing as we approach).

[nprev]

Slow rotation in itself would be a fascinating find. Most of the asteroids in the inner system we've visited seem to have rotation periods in single-digit hours.

If this turns out to be true then gotta wonder if UT might be completely pristine, as in virtually no impacts or outgassing throughout its history. Alternatively, if it is a contact binary then how was the system's angular momentum dissipated so much?

[scalbers]

NASA TV Briefing on now...

[rhr]

On where? I can't find a live stream from any of Emily's links.

[elakdawalla]

Sorry about that. I did my best with the information provided, but it turned out not to be accurate. Here is a partial recording of today's briefing but it's only 19 minutes' worth -- if anyone finds a full recording, please share it here! https://www.youtube.com/watch?v=N5BNOo4LJmM

[scalbers]

Looks like a full 30min recording here, now posted on the jhuapl site & YouTube channel.

Next briefing Dec 31 2pm EST.

[PDP8E]

We have seen several artist's interpretations of MU69 ... a contact binary ... an orbiting binary...

Here is a computer program's interpretation of MU69 ... a programmed hallucination ... but based on inputs of Vesta, Phobos, and the Lorri image released a few days ago (which was 10x if I am not mistaken but was used to constrain the program's output). The program crunched the data for 17 minutes and came up with the image below. This is what MU69 might look like from Lorri at about 50K km away... or probably not.



for your enjoyment only...

[Explorer1]

Well, we'll see next week how accurate that is!

[tanjent]

PDP8E, in the same spirit, I predict that the soon-to-be-revealed observations will bear "some" but "not too much" resemblance to your model image.

[MahFL]

1.9m miles now.

[jasedm]

Were this the Saturn system, we'd be within Iapetus' orbit now...

[Lucas]

Interesting tweet from Alan... perhaps they have resolved Ultima Thule?

https://twitter.com/alanstern/status/1079111629604831233

[MahFL]

Interesting tweet from Alan... perhaps they have resolved Ultima Thule?

https://twitter.com/alanstern/status/1079111629604831233

It seems to be something, but they are still too far out to resolve anything, except maybe if it's a binary or not ?
Also according to Emily's posted schedule no pics are due to be downloaded today.

[Alan Stern]

It seems to be something, but they are still too far out to resolve anything, except maybe if it's a binary or not ?
Also according to Emily's posted schedule no pics are due to be downloaded today.

Emily's article is about scirct science data. But all data are useful for science, even OpNav images.....

[dtolman]

Emily's article is about scirct science data. But all data are useful for science, even OpNav images.....

Squinting at where the wand is pointing in your twitter post, I'd say LORRI has resolved Ultima Thule into multiple pixels, right on schedule! I guess all will be revealed soon enough

[fredk]

I don't think he can see where he's pointing.

There appears to be a vaguely ringlike structure about the centre of that image (and darkness at the very centre). My guess: they've subtracted a point-source model (PSF) from the image where MU69 is predicted to be and see a residual around it, which would suggest it's starting to be resolved.

[john_s]

The raw image page is now up-

http://pluto.jhuapl.edu/soc/UltimaThule-Encounter/

Enjoy!

[nprev]

Thanks, John. I assume that the fact that UT is near the center of the frame is a very good indication of nav accuracy...?

[nprev]

Spaceflight Now is going to live-blog the encounter in real time from JHAPL.

[JohnVV]

artist's concept
do to software constraints a render of UltimaThule as a SPHERE


( this is basically my default KBO generator using Blender )

we will see in a few days , then something much closer to the real thing


PS.

dose anyone know of a naif spice kernel for New Horizon for the fly-by.
The last kernel ( nh_pred_alleph_od124.bsp ) has a end date of September 2018

[nprev]

Alan just reported on FB that they finished their last nav meeting a few minutes ago, so possible that there might be a REAL fresh one available soon.

[Bjorn Jonsson]

Interesting tidbit in the Spaceflight Now live-blog from Hal Weaver, there are some hints that Ultima Thule is a quickly-rotating object.

[Aldebaran]

Interesting tidbit in the Spaceflight Now live-blog from Hal Weaver, there are some hints that Ultima Thule is a quickly-rotating object.

Could that explain the lack of light curve? (temporal resolution constraints)

[Bjorn Jonsson]

Could that explain the lack of light curve? (temporal resolution constraints)

I doubt it - some of the light curve observations probably include images taken with a short time interval between the images and probably also a variable interval.

But if it turns out that UT really us a quickly rotating object that must be good news since it means NH will be able to observe a bigger part of UT's surface.

[MahFL]

0.9m miles now.

Failsafe 1 images download starts at 8:31 pm EST.

[dudley]

How fast would Ultima Thule have to be spinning, I wonder, so that the light curve would be smeared out into one consistent light level?

[Hungry4info]

It doesn't appear to be a binary object from this image.
(Processed by Daniel Bamberger (stacked, deconvoluted, enlarged)).

Attached thumbnail(s)

 

[Explorer1]

DSN Now shows 1.06 kb/ sec download! This is 'Failsafe 1', right?

[MahFL]

DSN Now shows 1.06 kb/ sec download! This is 'Failsafe 1', right?

Correct, download ends at 23:56 EST.

[WTW]

DSN communication seems to have stopped at 04:43UTC, with several bounces lasting until ~04:47 when the signal dropped.

With the exception of a weird signal drop at ~04:26UTC, signal strength was fairly steady at ~ -147 to -148.5 dBm throughout, indicating good tracking at Canberra and stable pointing by the spacecraft - a good sign...

[nprev]

Remember that DSN Now is not an authoritative source to determine what's going on with any given spacecraft. See this post re the Opportunity listening campaign.

It's definitely cool, but anything but official.

[angel1801]

Closest approach is just under 24 hours away. In fact, as of right now it is 23 hours and 1 minute to go.

[centsworth_II]

Interesting tidbit in the Spaceflight Now live-blog from Hal Weaver, there are some hints that Ultima Thule is a quickly-rotating object.

From Alan Stern's post #9 in this thread:
"We're looking for periods ranging from ridiculously long (weeks) to ridiculously short (2 hours). Nothing firm yet."

[nprev]

How fast would Ultima Thule have to be spinning, I wonder, so that the light curve would be smeared out into one consistent light level?

That's an excellent question. I suppose it would depend on how continuous the dataset was above all else and the rate of sample acquisition; would think that there would also have to virtually no detectable albedo variations at any distance much beyond where NH is right now, which is maybe not too much of a stretch for such a small (and likely primeval) object.

We should hopefully know well before C/A, though. That image Hungry put up looks SORTA maybe kinda oblong if nothing else, so it oughta spin around in a noticeable fashion.

[paraisosdelsiste...]

According to spanish newspaper "Publico", New Horizons is due to land in Ultima Thule tomorrow and also states that was launched in 1996. We've been trying all the morning to get that text updated, but seems impossible. Don't know where they've got all this information.




Anyway, there is a lot of expectation in spanish social media about the flyby, and that is really nice. Good luck for the team!.

[climber]

According to spanish newspaper "Publico", New Horizons is due to land in Ultima Thule tomorrow and also states that was launched in 1996. We've been trying all the morning to get that text updated, but seems impossible. Don't know where they've got all this information.




Anyway, there is a lot of expectation in spanish social media about the flyby, and that is really nice. Good luck for the team!.

Neither they’ve heard of the Voyagers and Pioneer 10&11th....

[scalbers]

It doesn't appear to be a binary object from this image.
(Processed by Daniel Bamberger (stacked, deconvoluted, enlarged)).

Interesting to see this result from the deconvolution (deconvolving?), since a number of the neighboring stars appeared to have an L shaped appearance in the raw images.

[MahFL]

Failsafe 2 should be downloading now.

[scalbers]

DSN Now (unofficially) indicates the downlink at 500b/sec from Goldstone.

[nprev]

Fingers crossed that the latest data gives some solid indication of UT's shape and consequently its rotation state.

[Hungry4info]

Press conference has started.

[nprev]

It's apparently indeed oblong, at least!

[Explorer1]

John Spencer confirms: elongated blob!

[Hungry4info]

Failsafe 1.

Attached thumbnail(s)

 

[nprev]

And STILL no apparent light curve.

[dtolman]

Now that its shape is apparent, are there explanations left besides it tumbling so slowly that its not apparent in images?

[Gladstoner]

I wonder if it could be a relatively smooth oblate ellipsoid rotating around the short axis? That could mask a rotation rate until details become resolved.

Here’s hoping for the unexpected...

[scalbers]

Has the elongation (possible fainter lobe) rotated ~180 degrees relative to the previous image 15 hours earlier? This (together with an absent light curve) would be consistent with a rotation axis aligned with the viewing direction.

NASA TV New Horizons Q&A is to begin shortly at 2015 UTC.

[Daniele_bianchin...]

ok. . Binary system is excluse?

[nprev]

No, still possible that it is a binary. Resolution is not yet good enough to determine one way or another.

[JRehling]

In the absence of any other forces, could solar radiation have halted its rotation in the orientation that presents the least "pressure"? That would indeed be a wacky possibility, but the Yarkovsky effect sounds wacky at first, too.

[WTW]

Again, a completely "unofficial" indication from DSN NOW:
The download signal from New Horizons seems to have dropped at approximately 21:03UTC. Again, the indicated signal strength was fairly stable throughout at about -147 to -149 dBm.

Almost simultaneously, antenna DSN26 at Goldstone began transmitting a very strong (79kW) signal directly toward MU69 and New Horizons -- presumably for the radio science experiment when that signal arrives hours later.

And meanwhile, it appears that all four antennas at Canberra are all aligned and arrayed and tracking New Horizons as it climbs above the Earth's horizon.

I know that DSN Now is not in any way definitive (and can be misleading), but these folks are actively involved in this endeavor. They never get to be up on the platforms at news conferences, but they are crucial. And fun to watch.

[Explorer1]

In the absence of any other forces, could solar radiation have halted its rotation in the orientation that presents the least "pressure"? That would indeed be a wacky possibility, but the Yarkovsky effect sounds wacky at first, too.

That far out from the Sun, I doubt that there's any significant pressure from light, at least for a natural object. We don't know of any slow rotaters beyond the Trojans.
Though given 4.5 billion years, many things are possible....

[nprev]

If it is indeed a slow rotator AND it's binary/contact binary that's even more puzzling just from a conservation of momentum standpoint. Would have had to have been an extremely low-velocity capture indeed and one or both of them had to be barely rotating in the first place.

I suppose it's possible that there were one or more encounters with or impacts by other objects at some point in the distant past that hit all the various vectors just right to create this hypothetical binary, but it is very empty way out there, not like the inner system at all. Not really buying that scenario.

[scalbers]

If it's a (non-contact) binary we'd be referring to a slow orbital revolution rather than rotation. My odds would favor a peanut shaped single object, like Halley or Borelli. This would mean a sizeable neck if it is a contact binary. At least so far there hasn't been any hint of a saddle point or minimum of pixel intensity between the two "lobes".

[Explorer1]

Less than 1 lunar distance now; 7 hours to close the remaining gap, just like after launch (Newton's First Law )

[Floyd]

At the press conference Dr. Spencer used a pen to demonstrate how if it rotates perpendicular to its long axis, and the rotation axis is facing you, you see the same surface all the time.

[JohnVV]

based on failsafe1 artist concept


as seen from NH

[HSchirmer]

In the absence of any other forces, could solar radiation have halted its rotation in the orientation that presents the least "pressure"? That would indeed be a wacky possibility, but the Yarkovsky effect sounds wacky at first, too.

Hmm, evaporation from the sunrise side removes mass and momentum, transfers it to the evening-side via condensation....

"In Lower Pomerania is the Diamond Mountain... every hundred years a little bird comes and sharpens its beak on it"
The Brothers Grimm

"You must think that's a helluva long time!... Two Billion years...Personally? I think that's a helluva bird"
Steven Moffat/Peter Capaldi

[MahFL]

Less than 200K miles now.

[Daniele_bianchin...]

My interpretation,

Attached thumbnail(s)

 

[angel1801]

One hour and 53 minutes to closest approach now.

[Gladstoner]

I'm imagining it as something with a form like Methone, but probably not as smooth. Perhaps this vast and remote neighborhood could have been quiet enough through the ages to prevent any disruptions that would result in an irregular form.

[Decepticon]

I expect a crater-less comet like object.

[MahFL]

I expect a crater-less comet like object.

I predict more than 1 crater.

[Explorer1]

Less than an hour left....

[Aldebaran]

Now that its shape is apparent, are there explanations left besides it tumbling so slowly that its not apparent in images?

Surrounded by millions of tiny orbiting particles

[MahFL]

Surrounded by millions of tiny orbiting particles

Hope not as NH would be destroyed.

[angel1801]

Only 9 minutes or just over 9000 KM to closest approach now.

[MahFL]

Only 9 minutes or just over 9000 KM to closest approach now.

Gratz to the NH team, hopefully everything worked ok.

[nprev]

We wait on the beach of a midnight sea, anxiously awaiting the faintest of comforting whispers from our small, small ship as she passes a distant, mysterious island faster than dreams, far beyond our horizon

Good luck.

[Tom Ames]

We wait on the beach of a midnight sea, anxiously awaiting the faintest of comforting whispers from our small, small ship as she passes a distant, mysterious island faster than dreams, far beyond our horizon

Good luck.

That's beautiful, and a wonderful and optimistic sentiment with which to start the new year. Thank you.

[Daniele_bianchin...]

We wait on the beach of a midnight sea, anxiously awaiting the faintest of comforting whispers from our small, small ship as she passes a distant, mysterious island faster than dreams, far beyond our horizon

Good luck.

A Good words.. Many Thanks . .����

[nprev]

Acquisition of signal for 'phone home' expected at approx. 1535 GMT, NASA TV live coverage beginning now! (1520 GMT)

[nprev]

Carrier!

[nprev]

TELEMETRY LOCK!!!

[Explorer1]

Telemetry coming down....

[nprev]

RECORDER POINTERS AS PREDICTED, EXPECTED AMOUNT OF DATA ACQUIRED!