New Horizons, Only 100 days from Pluto.

[DRT]

The dark stuff in the troughs could well be liquid of some kind between the cracks in the ice............leading me to think that an ocean below the surface is a real possibility.

Or they could be Plutonian Killer Whales making their way trough the sea ice looking for the open ocean

When i first saw the Heart of Pluto, my first thought was "Ice cap". Its seems to be that. Its weirs that it lies on the equator. Maybe we have it all wrong and Pluto is 90 degrees off axis and the heart of Pluto actually is located on either its northern or southern pole?. It would help if i (we) knew about any magnetic field on Pluto and how it works.

The Earth's axis is tilted by 23° - Pluto's by 123° it is more or less rolling along its orbit around the Sun.

The large string of circular features (the whale) that could be seen ad NH approached Pluto run along the equator, so the Heart lies between the equator and the north pole.

These two things combined mean that the Heart probably spends a few decades in total darkness whilst the southern hemisphere is facing the Sun as Pluto moves around its orbit.

[LukeSkywatcher]

These two things combined mean that the Heart probably spends a few decades in total darkness whilst the southern hemisphere is facing the Sun as Pluto moves around its orbit.

So as i said, the apparent ice cap on Pluto may well be on the equator (as we know it here on Earth)...........so if Pluto's Northern or southern pole is facing the Sun.........ice caps will form around its equator (the coldest least lit part of the planet).

[Stub Mandrel]

They reminded me of tundra polygons:

But it looks like they have similar things on Mars:

Now the Pluto polygons are 20 miles across, not 20 or 200 metres, but the similarity in shape could mean its similar physics - repeated incomplete melting and freezing. Is it a dynamic crust floating on a mantle of nitrogen that gasses out when Pluto warms up on its trips inside the orbit of Neptune?

[The Admiral]

Gosh, I wasn't even aware of something called a tundra polygon, and that's here on earth. To be honest, without reading the title, I thought it was a picture of crazy paving!

Ian

[Piero]

Another stunning image representing Pluto and Charon. 

The New Horizons has been doing an excellent work.

It is amazing that our generation is assisting to this big event and that we can see all these details immediately. 

[RLWP]

Seeing that image, Pluto and Charon are pretty close together. And they aren't wildly different in size either. I wonder what point each of them orbits around?

Richard

[Stub Mandrel]

It's slightly foreshortened, the separation is 19,000km which I work out as about 21 Charon diameters. Much closer than earth-moon. According to WP the 'barycentre' is at 17,000 km, outside pluto.

https://en.wikipedia.org/wiki/Charon_%28moon%29

[RLWP]

It's slightly foreshortened, the separation is 19,000km which I work out as about 21 Charon diameters. Much closer than earth-moon. According to WP the 'barycentre' is at 17,000 km, outside pluto.

https://en.wikipedia.org/wiki/Charon_%28moon%29

Ahh - thank you!

How cool is that!

Richard

[RLWP]

Hah - not as cool as this:

Pluto and Charon as imaged by New Horizons

What an amazing mission this is

Richard

[niallk]

All very cool

[DRT]

It's slightly foreshortened, the separation is 19,000km which I work out as about 21 Charon diameters. Much closer than earth-moon. According to WP the 'barycentre' is at 17,000 km, outside pluto.

https://en.wikipedia.org/wiki/Charon_%28moon%29

That isn't correct. The barrycentre is much closer to Pluto than it is to Charon, as shown in the diagram above. According to this Wikipedia page the barrycentre is 960km from Pluto.

[Stu]

That sounds correct. The 17k in stub mandrel's post is from the centre of Charon not Pluto. It puts it outside Pluto still though.

[DRT]

That sounds correct. The 17k in stub mandrel's post is from the centre of Charon not Pluto. It puts it outside Pluto still though.

Ah, I missed the comma in the sentence

Apologies.

[Stub Mandrel]

That isn't correct. The barrycentre is much closer to Pluto than it is to Charon, as shown in the diagram above. According to this Wikipedia page the barrycentre is 960km from Pluto.

I rounded the figures, 17,000 from 19,000 leaves 2,000 from Pluto, subtract half a pluto radius and its not that far off.... :-)

Ah, I can see my post could be read as 17,.,000 km from Pluto, not Charon...

[Astrobod]

Just spent the evening catching up the all the posts about Pluto & Charon, absolutely amazing pictures and data

[symesie04]

Hmm think we could be jumping the gun a little with all this talk of ice caps and sub surface oceans  Keeping in mind that its going to take 18 months just to download all the data and then i suspect it will be at least another 5 years before any serious theories are proposed.

Regarding the poles and equator i have yet to see it clarified anywhere when referring to them if it is from the perspective of our orbital plane or if referenced to via Pluto's highly irregular orbital path. I would assume the latter but the two would be quite different. The orbit of Pluto is i believe one of the reasons it was down graded from planet status.

[barkis]

Well,  Pluto spends 20 years out of 248 inside the orbit of Neptune, which is an indication of how elliptical it's path around the Sun is.

Perhaps the AU.  should reinstate Pluto as a Planet for those 20 years .

Of course they couldn't possibly relegate Neptune to that of a Dwarf Planet  .

I think the Information, and the images of both Pluto and Charon, have gone some way to forge a healthy respect for those

little bodies, because whatever designation the Powers that be have assigned Pluto and family, that remote little

group are  bound to our star,  and they have real  personalities now, I reckon.

Ron.

[impactcrater]

hear hear , Ron....it was never fair that Pluto got the flick when it was completely unknown. It is also so unlike Ceres which I can accept as a dwarf planet.

On another matter which has received some attention already, I was listening to Professsor Fred Watson , an eminent British-Australian Astronomer who says "Charon' should be pronounced as "care-on'.

This has Greek origins and I assume the Ch beginning refers to the Greek letter Chi or squiggley X. He doubts the Oarsman would like to be called Sharon...could some Greek scholars confirm this ?

PS lovely new pictures of the second lot of newly discovered Mountains on the "Heart'

[impactcrater]

re Lukeskywalker post on 19th...My Nasa reading says Pluto's Southern hemisphere is currently in Winter mode. Eventually, the Northern hemisphere will be...the concept of Rolling around the Sun is confusing and slightly simple. Whilst it is Rolling on its own axis it is not rolling about its'ecliptic'. This is much easier understood diagrammatically...but I can't do that.

Perhaps some expert can clarify this for us....

[Stub Mandrel]

hear hear , Ron....it was never fair that Pluto got the flick when it was completely unknown. It is also so unlike Ceres which I can accept as a dwarf planet.

On another matter which has received some attention already, I was listening to Professsor Fred Watson , an eminent British-Australian Astronomer who says "Charon' should be pronounced as "care-on'.

This has Greek origins and I assume the Ch beginning refers to the Greek letter Chi or squiggley X. He doubts the Oarsman would like to be called Sharon...could some Greek scholars confirm this ?

PS lovely new pictures of the second lot of newly discovered Mountains on the "Heart'

Charon in Greek (as in the boatman) is pronounced 'karon', but legend says it's discoverers wife's name was Charlene so it should be 'sharon' - but then again the discoverer was James Christy (kristy) so perhaps the wife story was a cover for naming it after himself ;-)

[Piero]

Other nice pics! 

Mountains in Pluto's heart: 

"This image was acquired by New Horizons’ Long Range Reconnaissance Imager (LORRI) on July 14, 2015, from a distance of 48,000 miles (77,000 kilometers) and sent back to Earth on July 20. Features as small as a half-mile (1 kilometer) across are visible. These frozen peaks are estimated to be one-half mile to one mile (1-1.5 kilometers) high, about the same height as the United States’ Appalachian Mountains. The Norgay Montes (Norgay Mountains) discovered by New Horizons on July 15 more closely approximate the height of the taller Rocky Mountains. "

source: http://pluto.jhuapl.edu/Multimedia/Science-Photos/image.php?page=1&gallery_id=2&image_id=242 

and the moons Nix and Hydra: 

"The image shows features as small as approximately 2 miles (3 kilometers) across on Nix, which is estimated to be 26 miles (42 kilometers) long and 22 miles (36 kilometers) wide. Pluto's small, irregularly shaped moon Hydra (right) is revealed in this black and white image taken from New Horizons' LORRI instrument on July 14, 2015 from a distance of about 143,000 miles (231,000 kilometers). Features as small as 0.7 miles (1.2 kilometers) are visible on Hydra, which measures 34 miles (55 kilometers) in length. "

source: http://pluto.jhuapl.edu/Multimedia/Science-Photos/image.php?page=1&gallery_id=2&image_id=241

[Grotemobile]

That is very good.

Nix & Hydra,

look like they are,

just lumps of rocks

really.

[Stub Mandrel]

Now they are really motoring!

A telling feature of the Pluto picture are a few flooded craters at the left that, unlike lava flooded craters on the moon, are disconnected from the pale plain.

My guess is that the paler stuff is an ice of some sort that has been liquid in the past and flooded and retreated, or at least melted/sublimed away.

[Northern Soul man]

Great thread Guys - just looking at the Mountains - they seem very "angular" to me - not much sign of weathering here by the looks of it - so to presume not much wind to weather the surface or very very young.

Paul

[RLWP]

Great thread Guys - just looking at the Mountains - they seem very "angular" to me - not much sign of weathering here by the looks of it - so to presume not much wind to weather the surface or very very young.

Paul

Time for wild speculation......

Crystals

Richard