New Horizons to flyby Pluto this year

My understanding is that it is going to take 16 months to download all the data rather than one month.

I think the most extraordinary thing is not the 'young' surface of Pluto, but rather the 'young' surface of Charon, suggesting that not just Pluto but also the smaller Charon is also geologically active. I wonder if it might have something to do with the relatives sizes of Pluto and Charon being quite close; Charon is slightly more than half the diameter of Pluto whilst all the moons of other planets in the solar system are relatively much smaller than their 'parent.' And they are also extremely close together; a mere 19,570 km compared to the moon at 384,400 km from Earth. On the other hand, as Pluto and Charon are both tidally locked and I don't think there's much variation in their separation, there shouldn't be much in the way of tidal forces at work. Curious...

Certainly going to give the geologists something to think about.
 
 
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It is interesting that we are really looking at a binary planet rather than a planet, albeit a dwarf one, with a moon. Strictly speaking Pluto and Charon are a binary planet with other moons circling around the pair of them.

Sadly @hardsciencefanagain, fascinating though those links are, I'm afraid they are way over the top for a layman like myself :oops: I can just about cope with their summary, introductory paragraphs!

Edit: on more reading it seems the scientists think that, though close, Pluto and Charon are too small for tidal forces between them to be causing geological activity and they are now speculating on radioactivity generating heat or even underground lakes. Though I can't see why the latter would retain heat any more than the body of the planet.
 
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I'm a layman,but reasonably well informed.
I learned to read articles like that,so my science is always sort of "straight from the horse's mouth"
I started out with Scientific American,American Scientist and progressed naturally to articles from the technical journals.Stick at it,and sooner or later the dime drops,so to speak.
 
Absolutely not. This one image that they've already received has no crater impacts on it meaning they estimate the surface cannot be older than 100 million years. A mere clock tick in geological times. They are apparently gobsmacked having expected a heavily cratered surface:

Alan Stern, the mission's chief scientist commented: "We now have an isolated, small planet that's showing activity after 4.5 billion years."

Prof Stern said the discovery would "send a lot of geophysicists back to the drawing boards".
Click to expand...

I love that: a lot of head scratching going to be going on I think! :)
 
Earth's early impact record is rather obscure,most craters have disappeared.
But:this because of geological activity
Might there be less reason for impact at the edge of the solar system?
 
I'm not sure, they've got the Kuiper belt to deal with and there are some craters on Charon, just very few. They seem pretty certain that the surface is 'young.' Compare it with the moon, rather than Earth, and then bear in mind that it is smaller than the moon.
 
hardsciencefanagain said:
Might there be less reason for impact at the edge of the solar system?
Click to expand...
No.
Nor does Pluto stay at the Edge of the Solar system. The lack of craters is because of geological activity. So now the puzzle is what is causing it.

Pluto and its moons have a very strange orbit. If anything, I'd have thought it would make is more vulnerable to other Kupier Belt objects, other objects in closer orbits and bits of comet or other stuff in Solar orbit.
 
I'm with Vertigo about being a layman for those articles. The math and even the symbology are beyond me. But I believe I can answer this question.

hardsciencefanagain said:
Might there be less reason for impact at the edge of the solar system?
Click to expand...

If I am right the answer goes in the opposite direction. Having Saturn and especially Jupiter in the outer orbits of the sun has significantly decreased the number of hits the earth takes. Being outside of their orbit as Pluto (are we going to start saying Pluto/Charon?) is that would increase the statistical probability of hits, not decrease them.
 
And bear in mind that Pluto and Charon themselves are now thought to have collided with each other and stayed locked together as the binary, rather than Charon being a chunk of Pluto knocked off by a collision with another body. And as Ray says, it does have an odd orbit where it is sometimes closer to the Sun than Neptune. They seem to think it used to be in a much closer orbit but got spun out by the gas giant bullies ;)
 
Vertigo said:
And bear in mind that Pluto and Charon themselves are now thought to have collided with each other and stayed locked together as the binary, rather than Charon being a chunk of Pluto knocked off by a collision with another body. And as Ray says, it does have an odd orbit where it is sometimes closer to the Sun than Neptune. They seem to think it used to be in a much closer orbit but got spun out by the gas giant bullies ;)
Click to expand...

This is all new information for me. Especially the part about being spun out of a nearer orbit by the gas giant bullies.


Edit: I did know about the eccentric orbit part.
 
Check this out:

It's part of a series of 'Pluto in a minute' videos that Nasa have released to YouTube. They're actually quite good, though the presenter is a little frantic, but then she is trying to cram a lot into each minute.

And from Wiki:
Simulation work published in 2005 by Robin Canup suggested that Charon could have been formed by a collision around 4.5 billion years ago, much like Earth and the Moon. In this model, a large Kuiper belt object struck Pluto at high velocity, destroying itself and blasting off much of Pluto's outer mantle, and Charon coalesced from the debris.[29] However, such an impact should result in an icier Charon and rockier Pluto than scientists have found. It is now thought that Pluto and Charon may have been two bodies that collided before going into orbit about each other. The collision would have been violent enough to boil off volatile ices like methane but not violent enough to have destroyed either body.
Click to expand...
 
The physics of celestial collisions* are not well constrained yet
err
*no pun intended:D
you just gotta love the exploration of space.
*fondly remembers Ley/Bonestell*
 
Oh groanations... Pluto has a very eccentric orbit around the Sun, which means its more volatile ices could slough off which would to a certain extent de-crater the surface. Don't forget the Pluto has just passed its closest approach to the Sun.

But whilst this would be a contributory factor to the new-ish surface, it is far from being the whole story. Yes there is a little bit of tidal heating, but not to make a new surface like that.

Radioactive materials producing heat? Possible, but unlikely because radioactive materials are usually the heavy elements whose atoms and molecules would have stayed close to the Sun when the Solar System was developing.

So the normal causes of a new geological surface do not explain the surface.

So how about a recent collision with Charon? This explanation would also go to explain the newish surface on Charon.

But there are two other possible explanations...

1) The sloughing off of material could be re-gathered onto the surface of Pluto and its moon to smooth things out and if you include icebergs being sloughed off and brought back to a semi-liquid surface, this could explain the 'cryo-volcanic' features we are seeing
2) Pluto was formed far away from the Sun. We can't say for certain what its internal structures are like, but I would not be surprised if they were so weak that they effectively suffer from a form of tidal heating, but not as we know it.

On the second point... fingers crossed that a certain editor accepts my latest science fiction story. Whilst not located on or around Pluto, it does give some insight in the possible processes.

Right... that's the end of my rant... for now...
 
Yes, highly eccentric orbit but it's closest point to the Sun is only just inside the orbit of Neptune, I wouldn't have thought that was close enough for significant sublimation, but I may be wrong. And it's thought that it wasn't formed nearly as far out as it is now (see my #56 above)
 
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