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

[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!