I've made a quick and dirty rotation movie with the LORRI frames taken the days 6, 7, 8, 9 and 10 and some features seem to be consistent between frames.

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Somewhat similar to Triton...... Pluto and Triton have very closely-matched densities too. I think the case for Triton being a captured KBO may be strengthened further following the flyby of Pluto next month.

I wonder if we'll see any 'canteloupe' terrain?

Or geyser plume trails?

Pluto and Triton may be very similar in terms of size and bulk constituency, but they are very different in terms of seasons: Triton maintains a scrupulously constant distance from the sun, but the sub solar latitude varies radically and non-sinusoidally. Pluto has a wide range of distance from the Sun, but everything should be very regular and periodic. This may make for a big difference in how frost or anything else pertaining to variations in illumination is distributed and/or redistributed.

The dark line seen in Bjorn's work got me thinking. Elsewhere in the solar system, what does a long, large linear (but not perfectly linear) feature indicate? Often, it's a sign of geological activity, either extension or horizontal movement. Other causes could be volatiles in motion. Another possibility is that the line is merely the negative space between other things, although this becomes unlikely if the two edges are parallel over long distances.

By and large, geological activity, past or present, is most common. That would be very exciting. But then again, Pluto might break every rule we've ever thought of.

Looking at the possible dark collar around Pluto's pole and comparing the NH images to schematic views (rotated to match the viewing geometry) with a lat/lon grid seems to indicate that the 'collar' is located very approximately between latitudes 40 and 60 degrees north. But this is all very tentative. Even though the presence of the dark, diagonal line in the image I posted yesterday can now be considered certain (it's also seen in later and earlier images processed by me and others), the presence of a polar collar is in my opinion far from certain yet.


I also have doubts about big similarities between Pluto and Triton, for one thing Pluto exhibits much bigger albedo variations than Triton at comparable resolution.

Could the albedo variations on Pluto be caused by clouds? I ask because Pluto does have an atmosphere though it is tenuous.

It's not just tenuous, it makes Mars look like Venus in comparison (post may not be 100% hyperbole-free). So no, not likely at all that real clouds could be present - thin atmospheric hazes maybe, probably only visible above the limb. These brightness variations are most likely to be variations in surface ice cover. But we explore because we don't know, so we could be surprised.

Phil

Oh there might not be any more atmospheric pressure than what was found at Triton. So no clouds, but as it is freezing out there should be some haze yes. But the cameras might not catch it since this ghost of an atmosphere is stirred by Charon and a whisp of it might even wrap also that largest satellite at times.

Pluto's base atmospheric pressure is about like the Earth's mesopause....where noctilucent and polar mesospheric clouds form. I would not so quickly discount the possibility of condensation clouds and/or aerosol hazes-- we will see.

I recall the Uranus and Neptune flybys back in the 80 s. At the time I had to check any info from TV programmes covering the events and there weren't many. This day and age when you get social media and blogs It will be much easier to follow the Pluto flyby and the experience of such an encounter even more thrilling and exciting. Enjoy the ride. Thank you Alan Stern and NH team for this opportunity!

Thank you for your correction Alan. And I should have known since I have indeed seen noctilucent clouds a number of times, and over the years even gotten some nice images of a few. Yet, I did not discount haze, we'll have to wait and see. =)

Latest from yesterday.
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Edit: Failed to disclose this image was processed with a histogram adjustment and a max entropy deconvolution process set to low impact.

Looks like we may be seeing albedo variations on Charon now. Wow. Wow!

So incredibly cool in every sense of the word...

I'm running Eyes On The Solar System 24/7 at the moment. Just fun to ride along and watch the distance tick down.

Indeed any clouds/haze would have to be pretty optically thick to be so bright at this low of a phase angle. One might also compare what the atmospheric pressure is high up on Titan where the haze starts to become optically thick, as a rough analog.

Any chance that polar ice brightness could be enhanced by a slight sun glint effect? The geometry appears to be somewhat favorable if we consider a bi-directional reflectance function (BRDF).

Extended my latest Pluto/Charon raw image animations to include today's images; so now they go through 5-11 June, roughly covering one rotation for Pluto and Charon. The growth of Charon's apparent size is visible as the animation restarts, as is the acceleration of the growth of Pluto's apparent size.

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New deconvolved images released. No word on Charon.

Down-scaled 4-frame version:


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Media schedule is out now; quite busy!

http://www.nasa.gov/press-release/nasa-ann...for-pluto-flyby

For some reason that makes it even more real, that this is actually happening... time to dust off the ol' swear jar soon!

Here is a different processing of the deconvolved frames, greatly exaggerating brightness variations to show subtle features.

Phil

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So I'm confused about their animation. I see it and it appears that it rotates correctly as an animation but not like other images we've been seeing. Has this just been rotated to the right 90 degrees? It looks like, and they even annotate it as if NH is approaching Pluto right in its equatorial plane. Completely confused here.

The raw images are rotated around the camera z-axis, each series differently. So if you try to register the raw images, you need to align them according to the faint background stars, or use the filename as timestamp, together with the known orbital period of Charon to rotate the raw images correctly.

That looks exactly like Mars when imaged through a small telescope, although contrast seem a bit stronger (even taking into account processing).

These are the frames taken from the new video, giving a full rotation.

Phil

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Phil, that's excellent, thanks!

In fact, comparing it with the average of Buie's maps in post #82, the very bright spot at ~180 deg and the much darker spot next to it on the older map appear to be very much confirmed. (This assumes both the maps and your thumbnails are in the same coordinate system--are both right-hand rule?) Is the dark region on the bottom of the 281 degrees image in the area to close to the south pole to be mapped in the older data? Is this our first hint of "new" features?


Jeff

Could it be some residual feature from the formation of the Pluto/ Charon system such as impact scars from the original collision? Something analogous to the Vallis Marineris on Mars perhaps. It's never too early to speculate.

In the image from the new video, centered at 17 degrees, it almost looks as if there is a crater about 1/3 of Pluto's diameter, near its South pole. The bottom rim of this supposed crater seems to be faintly visible, at the very bottom edge of Pluto's disk. It surrounds a dark elliptical area, which is presumably the correct shape for a crater seen at the indicated angle.

Taking those images I posted above, and a bit of crude fudging rather than a proper reprojection (because I should be doing something else) - hey presto, a map, north up, 0 longitude at the left edge.

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And a comparison with an average of several maps by Mark Buie (see near the start of this thread):

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I can see my latitudes are a bit out, but I'm not sure why just yet.

Phil

For those who didn't click, and for the record here, the near term has the following events in store for us:

June 16, 23 and 30 (WEEKLY)
11:30 a.m. -- Mission Updates

July 7- 12 (DAILY)
11:30 a.m. -- Final approach to Pluto; live daily mission updates on NASA TV

Daily updates? I'm swooning. It'll be like the first few days of a Mars lander mission!

The forum's appropriately modest collection of emoticons doesn't include any that is sufficient to celebrate this good news.

TTT (remembering the days when the daily MER briefings were on CSPAN but weren't archived for long)

Bellissimo collage Phil..
What kind of energy can 'cause Pluto in CHaron and Charon in Pluto?
marea force?
Pluto-Charon ratio is much small compared to the Earth-Moon ratio.
Earth-Moon ratio farther thAn hydra.
Thanks, Daniele

Do you mean tidal forces?

Today, Charon and Pluto are tidally locked. There isn't any tidal flexing going on, so no heat is being generated and any current activity is unlikely. When they formed, though, they were much closer, and the tidal interaction would have been very strong before they became locked.

In fact, at a recent New Horizons Science Team Meeting, Bill McKinnon explained that Pluto may still be oblate as a relic from its high spin rate after the Charon-forming collision. Relaxing from that state could lead to a lot of fault systems on the surface, and these should be easy for NH to map if they exist.

yes.. tidal forces (marea forces in italy).
sin .. :-/
I hoped that generated a some 'heat yet..
I have forgotten that Pluto and Charont are tidally locked..my fault

It's interesting to note that Mars, Venus, and Titan all have some sort of massive, roughly east-west, chasm near or at the equator.

But larger worlds don't show any scars from formative collisions. Vesta, however, does. I suspect that Pluto is big enough to have put itself back together and gone on evolving after its formative events – closer to Mars than Vesta. But we'll see.

It's interesting to compare oblateness to what would be expected from present day rotation rate on various bodies. Iapetus for example seems more oblate than I would expect. Ceres is actually in equlibrium.

The circular dark area near the bottom of the disk in the best-processed of the recent images looks like a huge basin to me. One that either has a very dark floor, or that is in shadow as it rides the terminator 'round and 'round like a carousel. If so, the sun shining on its ramparts may be what has made Pluto look really lumpy in the early approach images.

Some of the lumpiness is apparently due to image processing artifacts. The basin or crater-like feature near the bottom of the images appears real enough, though. If it were a crater, its size would indicate an impact on the verge of having the power to disrupt Pluto. Similar in proportion to the Herschel crater on Mimas. Supposing an impact, it seems it would have had to either come in from a low angle, or had an orbit well above and below the ecliptic.

Recall that Pluto's orbit is inclined more than 17 deg from the ecliptic. Given that we don't know yet whether this thing is an impact basin or an albedo feature or something completely unexpected it's probably a bit early to start drawing inferences about the orbital parameters of a postulated impactor.

Agreed, Nick -- but in terms of speculating based on the best available images, I have to say that the first three of that four-image set are extremely suggestive of a basin. Especially (in my re-posting of just the first three images, below) the middle and right images. The left image shows an entire circular feature that could be just an albedo feature, but the second shows it on the terminator, partially shadowed, with what appears to be a far rim in sunlight. That suggests the far edge of the circular feature is raised above the center of the feature. The right image shows a similar lighting of the far rim, but Pluto's aspect to the sun has changed somewhat and the portion of the far rim illuminated is slightly different.

Again, yes, I could be reading too much into images of still-poor resolution. But on most (if not all) bodies in this solar system, a circular feature this large in comparison to the size of the body is an impact feature. I guess I'd say I would be very, very surprised if this isn't a basin. I'd even place a bet on it, if I had any money to bet with...

-the other Doug

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This like Mare Crisium and the Crisium basin. One is a dark patch, the other is a hole in the ground. At this stage it is impossible to tell which we are seeing. It might be both as on the Moon, but it might be just albedo.

Phil

2015-6-11 - 4 stacked with deconvolution

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Heres the stacked image without deconvolution as well.

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And just for good measure, a flip animation to make it easier to see if artifacts may be at play.

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Right on the money--we conducted a successful Pluto targeting burn this a.m., just 52 cm/sec, and right on target!

Great news, Alan: thank for the update!

I don't know why using a dart board for Pluto-Charon feels so appropriate. It just works.

It's a stochastic system. The Universe is thumbing it's nose at G*d...

--Bill

This is a composite of the four June 13th LORRI frames, 4x enlarged.

Phil

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This is getting so good I am seriously considering installing IRAF on my Mac so I can mess with the images and play with deconvolutions.

Folks here doing deconvolutions, are you building the PSF from the stellar images in the long exposures? If not, maybe I'll give it a shot.

Here is a quick attempt at processing the two unbinned 2015-06-15 05:00 images obtained at a range of 34.9 million km. This is a stack of the two images from this time, sharpened and denoised in Registax and then slightly sharpened with an unsharp mask in Photoshop. The images are enlarged by a factor of 4. The viewing geometry is also shown.

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The subspacecraft longitude is -3 degrees [corrected - I initially posted an incorrect longitude].

Most of the large scale details on Pluto in the image above should be real but the exact shape of these features might differ a bit from what this processed image shows. What's really interesting is that now Charon is starting to show details too (there have probably been hints of these details in earlier images but they are becoming more obvious now). There is very probably a dark feature in Charon's left 'half' but its exact shape is probably different from what the image above shows. But if the image is compared to the diagram it looks as if Charon's polar region may be darker than the terrain farther from the pole - this is rather tentative though but should soon become clear.

More to come...

Here's a 4x enlargement with no other image processing (I promise). The dark boundary outside of the polar cap seems to be real.

I'm also noticing a large surface marking on the left side of the Charon image.

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I suspect that with some image processing Nix and Hydra are probably now visible in these 1x1 bin images.

http://pluto.jhuapl.edu/soc/Pluto-Encounte...sure=100%20msec

Andy

My version of the newest images - it's not a deconvolution, just a merge of differently stretched versions of the image. I think the Charon dark feature is probably real, and it will be good to see it become clearer very quickly now.

Phil

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Below is the June 15 data stacked and processed with some luminance adjustments and a max entropy deconvolution.

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And also a blown-up flip between the stacked frames output and the further processed image.

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Lots of details becoming visible here.