Newly Released Triton Images from Voyager 2

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MeteorWayne

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SDC had an article about this today, so here's a link to the NASA site. Perhaps Andrew will have a go at posting some images here.

http://www.nasa.gov/mission_pages/voyag ... 90825.html

Newly released images commemorate the 20-year anniversary of the Voyager flyby of Neptune's moon Triton on Aug. 24, 2009.

Triton was the last solid object visited by NASA's Voyager 2 spacecraft as it headed toward the edges of our solar system.

Triton, Neptune's largest moon, is one of the "coolest" objects in the solar system, literally, with a surface temperature of minus 235 degrees Celsius (minus 391 degrees Fahrenheit). Voyager 2 discovered that Triton has active geysers.

The images and a movie show the moon's sparsely cratered surface with smooth volcanic plains, mounds and round pits formed by icy lava flows
 
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Re: Newly Reeased Triton Images from Voyager 2

Hi Wayne,

I'm very happy to oblige & really love this sort of thing. :mrgreen:

Below: A 250 by 200 KM reqion showing what appears to be frozen 'lakes' & certainly these plains are of cryovolcanic origin, most likely from the enormous tides raised by the event of Triton's capture by Neptune.

Vertical profiles have been exagerated 25 times, to make interpretation easier.


A 500 KM wide area showing very distinct cryovolcanic pits. Vertical profiles have been exagerated 25 times, to make interpretation easier.



I will be back later with some more as well as some imagery that I have worked on myself.

Andrew Brown.
 
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3488

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A 500 Km wide section clearly displaying a wide range of terrain on the large ice covered Neptune moon. Some 'smoothish' plains are clearly visible to the bottom left & Triton thus far (bearing in mind north of the low latitudes in the northern hemisphere remains unimaged) is sparsely cratered, the largest impact crater seen to date is 27 KM across, pretty small for a body the size of Triton.

Some more cryovolcanic pits are visible to the upper right.

Triton has clearly been geologically active into the recent geological past. Triton is quite likely geologically active now, aside from the liquid nitrogen geysers.

The terminator (day / night boundary) shows some relief, but Triton lacks deeps canyons & lofty mountains, possibly due to the surface being warmed & relaxed during the tidal heating phase during the capture by Neptune.

Water ice also relaxes over time & this is certainly true on the large Jupiter moons, Europa, Ganymede & Callisto, but then, as compared to Triton, they are positively tropical at a balmy average of minus 146 Celsius, as compared to Triton's average of minus 235 Celsius.
Vertical profiles have been exagerated 25 times, to make interpretation easier.


Triton based on Voyager 2 tracking data appears to be differentiated, with a large rocky core, surrounded by a water ice mantle & a crust of water & various ices. This could also be very similar to the large KBOs Eris & Pluto.

Below. Schematic of Triton's possible interior.

(1) Crust of various ices.
(2) Water ice mantle.
(3) Silicate rocky core.


Andrew Brown.
 
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MeteorWayne

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I still vividly recall to this day when the first images came down live from Voyager. I believe it was broadcast live on (probably) PBS. The salmon color and the incredible variety of the landscape left everyone at NASA (or was it JPL?) as well as this viewer absolutely dumbstruck. It was not what was expected at all.
 
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MeteorWayne":3fmohliq said:
I still vividly recall to this day when the first images came down live from Voyager. I believe it was broadcast live on (probably) PBS. The salmon color and the incredible variety of the landscape left everyone at NASA (or was it JPL?) as well as this viewer absolutely dumbstruck. It was not what was expected at all.
Hi Wayne, IIRC did you say once before that you were presernt at JPL during Voyager 2's encounter with the Neptune system?

I was at a college in Wales, United Kingdom, called Coleg Elidyr, & I had access to TV news & newspaper reports. It became very clear, very qickly that the encounter was an enormous success & that Triton literally blew the socks off the scientists.

Triton, like the Jupiter moons Io & Europa, Saturn moon Titan & the huge array of features on the Uranian moons before hand, proved that it was not possible to predict what a planetary body would be like.

Triton put paid to the notion that cold bodies far from the Sun, would be dead & inert. Neptune herself threw out many surprises, with the ferocious winds & storms. Triton was just, not what anyone expected.

We'll see what New Horizons finds at Pluto & Charon. I really hope that ARGO / New Horizons 2 gets approved & launched. We'll then see much of Triton's northern hemisphere in close up for the first time.

I will be back later with some images I have worked on.

Andrew Brown.
 
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MeteorWayne

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No, I wasn't there :) I wish!!
I just saw the images as they came down live... :ugeek:
 
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3488

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MeteorWayne":30psstbu said:
No, I wasn't there :) I wish!!
I just saw the images as they came down live... :ugeek:
Still that's quite an experience. I remember Phoenix Mars Lander EDL & first images in May last year, I stayed up pratically all night for that & that was a thrill & also terrifying during EDL.

I would love to be at NASA / JPL / JHU, or wherever when a planetary encounter or landing is taking place.

Despite my slow connection right now, I have at last been able to uplink three images I have worked on of Triton.

First is a crop showing three geysers against softened craters & a rille in the foreground.


Second a sharpened enlargement showing some strange blister like dark features, certainly cryovolcanic.


Lastly for now, is a departure crescent Triton in true colour, that I've cropped, enlarged & sharpened. The south pole of Triton is roughly half way along the crescent & over the limb.


I will be back with more.

Andrew Brown.
 
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CalliArcale

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*drools*

More Triton! Those pictures are astonishing. It's such a strange, strange world. I particularly like the crescent at the end. Sure, you can't make out much surface detail, but it's very evocative.

Another new surprise in old Voyager 2 images: a transit of Despina across Neptune:
Despina, Moon of Neptune
 
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3488

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Wow Calli,

That's incredible & I have not seen that before. Despite Despina's smallish size of approx 150 KM across, that is quite some shadow on Neptune's cloud tops. Despina orbits approx 52,500 KM from Neptune & completes one orbit every 8 hours.

I have cropped & enlarged below the central portion of a frozen 'lake' on Triton. The area shown is approx 200 KM across.


An area approx 400 KM across on Triton I have cropped & enlarged showing many softened craters. Their circular shapes are still visible, but the craters really are ghost craters as he surface warmed & relaxed, then refroze solid again. Note the lack of newer, fresh craters.

What ever softened these, most likely related to the event of tidal heating caused by Triton's capture by Neptune, ocurred within the 'recent' geological past, though AFAIK the cratering rates within the Neptune system is not well known. Perhaps Wayne knows more on this???


A crop & enlargement of two crossing graben on Triton. Note the narrow ridge running along the centre of the graben. Possible upwelling of slushy ice??? Area shown is approx 1,000 KM wide.


A crop of a section of 'ice bridge' between two frozen 'lakes' on Triton. Cropped section shown is approx 150 KM.


An enlarged crop of the giant frozen nitrogen ice south polar cap on Triton. Nitrogen ice is subliming around the edges & is thought to be refreezing in the darkened Winter north polar region. Note the many dark geysers here, over 500 have been identified.


Voyager 2 looks back on the south polar crescents of Neptune & Triton.


Andrew Brown.
 
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