New Horizons: Pre-launch, launch and main cruise, Pluto and the Kuiper belt Options

[Alan Stern]

New Horizons Team Sticking to Original Flight Plan at Pluto

June 14, 2013

Unless significant new hazards are found, expect NASA’s New Horizons spacecraft to stay on its original course past Pluto and its moons, after mission managers concluded that the danger posed by dust and debris in the Pluto system is less than they once feared. .....

http://pluto.jhuapl.edu/news_center/news/20130614.php

[ngunn]

Great news! We want all the pictures and all the science. Good luck.

[SpaceListener]

How did they anticipate lower risks of presence of dust and debris?
I suppose it is not a conclusion from the optical point of view but
somewhat from maths and physics law properties?

[Explorer1]

The conference next month should have the whole story from start to finish, I imagine.
https://dnnpro.outer.jhuapl.edu/plutoscience/Home.aspx

[john_s]

How did they anticipate lower risks of presence of dust and debris?
I suppose it is not a conclusion from the optical point of view but
somewhat from maths and physics law properties?

Actually it's a combo. We estimated limits on the amount of dust in the small-satellite region near Nix, Hydra, P4 and P5 from Hubble observations, and then used physics-based models of the likely distribution of the dust to extrapolate to the likely amount of dust in the region the spacecraft will pass through (which will have much less dust than the Nix/Hydra region, thanks to Charon's clearing effects). Plus we made improved estimates of the probability of damage from a dust impact of a particular size, which showed that the spacecraft is less likely to be damaged by small particles than we had initially thought. Alan's PI Perspective article has more details.

John

[TheAnt]

Thank you for the update and explanation John_s and Alan Stern. =)

I also do like the idea of that fail safe contingency plan of sending some data and images from the approach ahead of the closest passage.

[brellis]

More moons = less dust, or more organized dust?

[centsworth_II]

More moons = less dust, or more organized dust?

I think Charon alone can take credit, according to the PI Perspective linked by john_s.

...we're headed to a closest approach in the region that Pluto's Texas-sized moon Charon efficiently clears of debris. In fact, Charon offers such a good hazard-removal service that even if a recent impact onto a small moon created debris near Charon's orbit just months before encounter, Charon would clear almost all of it by the time the spacecraft arrives.

[Paolo]

Votes are in from the public for official names for newly-discovered P4 and P5.

finally it's Styx and Kerberos http://www.iau.org/public_press/news/detail/iau1303/

[dlilb200]

After years of reading these forums I finally have something to contribute - New Horizons is now 4 billion km from the Sun!

I very much envy the people who have had or now have the opportunity to work on this project. 876 million km to go! God speed New Horizons ....

[Paolo]

meanwhile, New Horizons has spotted Charon http://pluto.jhuapl.edu/news_center/news/20130710.php

[Julius]

Given the close proximity of Charon and Pluto I could imagine that both would exert tidal forces on each other with heating effects within both celestial bodies very similar to the Earth Moon system! This makes me think of tantalizing possibilities even as this far out as they are in the solar system! Its only a matter of time now.

[djellison]

They are tidally locked to each other - I don't imagine there would be a great deal of tidal heating as a result.

[john_s]

In the early days there would have been a lot of tidal interaction- the pair probably formed in a giant impact much closer together than they are now, and then moved apart, with Pluto slowing to synchronous rotation with Charon in the process. Once everything synchronized the tidal stresses would relax and any fracturing and heating would cease, as Doug says, but it's possible we'll see the effects of the early tidal evolution on the surface of Charon at least, perhaps as a system of fracture patterns. On Pluto my bet is that subsequent activity will have erased any such traces, but I could be wrong.

John

[djellison]

I wonder if either/ both will have a two-faces appearance like the moon does with it's near/far side differences. And on top of that, I wonder if there's a chance for the sort of effects in play on Iapetus.

So many questions - and the thing is....after NH....we'll have answered a few, but I bet we'll have even more.