New Horizons Pluto System Final Approach, 28 Jun-13 Jul 15 Options

[nprev]

More than nine years in flight, many more years before that in the making--this is the time. Please post all comments related to New Horizon's passage through the Pluto system here.

What to expect

Reminder that despite the rather brief duration of the actual encounter, it will be literally months before all acquired data is returned so this thread will be active for an equivalent time. Intrepid TPS space journalist and UMSF admin Emily Lakdawalla has written an excellent guide to planned imagery activities. EDIT: Updated version of guide. Emily has also produced a simulation of the kinds of images that are anticipated.

FAQs

Most Forum members are advanced spaceflight enthusiasts; many are in fact professionals in space-related disciplines. Accordingly, there are no plans to post answers to questions that can be easily answered via a Google search, and we ask that everyone please attempt to do so before posting a question.

EDIT (4 Jul 15): Admin Astro0 has produced an extensive New Horizons FAQ thread.

EDIT: Review rule 1.9 and keep it firmly in mind before posting. Posts violating that rule will be deleted without notice.

____

With all that said, the most important thing by far is to witness the marvel of discovery, of exploration, of New Horizons on worlds never before seen. This is the best seat in the house for doing so, right in the comfort of our own homes. As with previous major events in planetary exploration over the past decade it is likely that not only professionals but also the press may be watching the Forum during the coming days due to its hard-earned reputation as a place for noise-free commentary and stunning contributions by amateur image processors, so please bear this in mind...

...and I can't stop smiling with anticipation and excitement. What marvelous things we will soon see. Enjoy the ride!!!

[um3k]

I was born the same year Voyager visited Neptune, so this is the first of this sort of brand-new-world flyby* in my lifetime. It's super exciting!

*Excluding comets and asteroids, but I've arbitrary limited the meaning of "world" to bodies that won't let you accidentally tumble off into space.

[brellis]

I remain curious about what can be learned from SOFIA observations of Pluto's June 29th occultation of a 12th mag star, and if it will have any bearing on the final opportunities for course correction.

Googling "New Horizons Last chance course correction" - from this article:

A third opportunity for a trajectory correction maneuver is also marked just a week from now, on June 24, to be followed by a fourth one on June 30 and a final one on July 4, just 10 days before New Horizons’ closest approach to Pluto. Whether these future trajectory correction maneuvers will take place, however, will depend on the results of the mission’s ground teams’ continuing study of the optical navigation images that are being returned by New Horizons’ onboard Long-Range Reconnaissance Imager, or LORRI, and the assessment in particular of the debris hazard to the spacecraft from any free-floating dust particles that may be present around Pluto.

[Superstring]

I was born the same year Voyager visited Neptune, so this is the first of this sort of brand-new-world flyby* in my lifetime. It's super exciting!

*Excluding comets and asteroids, but I've arbitrary limited the meaning of "world" to bodies that won't let you accidentally tumble off into space.

Same. I count Ceres as a new world, but this is the first exploration of a *system* of worlds since 1989. It's also the first exploration of a world most of us have known about since childhood, which makes it extra special to me.

[Habukaz]

First new world to be explored for the first time since Neptune with an atmosphere to speak of, I suppose we can say that much.

(though Titan almost ruins this one, too)

[David S.]

I always think twice before saying anything not to add noise to this wonderful place, but I can't resist this time since this encounter will finally put an end to a 26 years long wait for me. I was 14 in 1989 when, right after the Neptune flyby, I started dreaming of seeing "the last one" up close in my lifetime.

There were times when I doubted it would happen but thanks to Alan and the amazing team behind this endeavour, that long wait will soon end in the most delightful way ! So, thanks a milion times to all the people involved for making this fourteen/forty years old happy

Going back to lurk mode now, eyes wide open !

[Tom Tamlyn]

Nature has posted an interesting non-technical article about the difficulties faced by New Horizons' two navigation teams.

[nprev]

MOD NOTE: My fault for not making this clear in the kickoff post, but please review rule 1.9. Pluto's classification as an object will not be discussed here, period.

Fully understand the emotional connotations of this ongoing debate, but it is for precisely that reason that the topic is banned. One post removed for that reason. Please don't try to dance around it. Thanks.

[jgoldader]

Maybe a little fun; is there a poll facility on the site? We could puree our collective brains into a jar and come up with the official unofficial UMSF list of predictions. For example,

New Horizons will see: (choose one)
No visual evidence of an atmosphere on Pluto
Limb haze on Pluto
Clouds on Pluto

New Horizons will see: (choose one)
No visual evidence of an atmosphere on Charon
Limb haze on Charon
Clouds on Charon

Number of new moonlets that will be discovered: 0, 1, 2, etc.

New Horizons will see:(choose one)
No evidence of recent geologic activity of resurfacing events on Pluto
Evidence of recent resurfacing but no ongoing activity on Pluto
Ongoing activity (geysers/etc caught in the act) on Pluto

New Horizons will see:(choose one)
No evidence of recent geologic activity of resurfacing events on Charon
Evidence of recent resurfacing but no ongoing activity on Charon
Ongoing activity (geysers/etc caught in the act) on Charon

Hydra and Nix will be: (choose one)
Roughly spherical
Irregular in shape
Artificial, the Mi-Go shipyards of Yuggoth (sorry, big Lovecraft fan)


Etc.

[JRehling]

A bit of saccharine sentimentality, echoing an earlier post:

We will almost certainly never again in our lives see a world this big up-close for the first time, and perhaps no people will for many generations to come.

The biggest world closer than Neptune which we haven't seen up-close is Pallas, a quarter Pluto's size.

For fans of first looks at a world, this is the Omega. We'll probably get first looks at many small bodies: Comets, asteroids, and hopefully TNOs in the path of New Horizons, but to the extent that geological complexity requires some sort of minimum size, this is the last gasp.

The next time we get new science of such an interesting planetary body of this size, it will be something extrasolar, just a pixel across, giving up a few secrets to light curves, photometry, and spectroscopy.

Savor this. It's the last time.

[Mongo]

For fans of first looks at a world, this is the Omega. We'll probably get first looks at many small bodies: Comets, asteroids, and hopefully TNOs in the path of New Horizons, but to the extent that geological complexity requires some sort of minimum size, this is the last gasp.

The next time we get new science of such an interesting planetary body of this size, it will be something extrasolar, just a pixel across, giving up a few secrets to light curves, photometry, and spectroscopy.

There's always Eris, although I doubt I will still be around when it is finally visited.

[Superstring]

There's always Eris, although I doubt I will still be around when it is finally visited.

Perhaps I'm being too optimistic, but I like to think we'll visit another big KBO in the next 50 years -- especially if Pluto proves to be really interesting. Probably not Eris, though, since it's so far away right now. I predict Haumea will be next, and hopefully some of us will be around to see it.

Either way, this flyby is historic and I'm thrilled to be around to take it in.

[Explorer1]

Sedna too, assuming a propulsion breakthrough in a couple of decades.
Also the unmapped hemispheres of Triton and the Uranian moons (though they're not quite in the same category of 'first time', I'll admit!)

[nprev]

Copied a portion of Habukaz' calculated LORRI resolution & major object image widths for the next two weeks as a quick reference. Original post here:


29.06: 86.5 km/px - Pluto 28 pixels across, Charon 14 pixels

01.07: 74.7 km/px - Pluto 32 pixels across, Charon 16 pixels
03.07: 62.6 km/px - Pluto 38 pixels across, Charon 19 pixels
05.07: 50.9 km/px - Pluto 47 pixels across, Charon 24 pixels
07.07: 39.0 km/px - Pluto 62 pixels across, Charon 31 pixels
09.07: 27.1 km/px - Pluto 89 pixels across, Charon 45 pixels
11.07: 15.2 km/px - Pluto 158 pixels across, Charon 79 pixels
12.07: 12.7 km/px - Pluto 189 pixels across, Charon 96 pixels

[fred_76]

It is much easier to use these formulae to determine the size in pixels of the objects :

Pluto : 392/N px
Charon : 205/N px
Styx : ~3.5/N px
Nix : ~7/N px
Kerberos : ~5/N px
Hydra : ~8/N px

resolution = 5.9*N km/px

where N is the number of days (decimal number) before NH goes through the planetary system.

[i]For example, right now the number of days remaining is 15 days 5 hours, this gives 15.2 days.

The diameters are :

Pluto : 26 px
Charon : 14 px
Styx : < 1 px
Nix : < 1 px
Kerberos : < 1 px
Hydra : < 1 px
resolution = 90 km/px

A view of sizes, with the Moon as a model, full size :

[Habukaz]

The SOFIA telescope is observing Pluto occultating a star today; does anyone know if results of this will be available before the Pluto encounter? It would be interesting to know if Pluto's atmosphere is still growing, remains stable or has started shrinking.

Maybe a little fun; is there a poll facility on the site? We could puree our collective brains into a jar and come up with the official unofficial UMSF list of predictions.

Another option would be to have a separate thread where members are invited to post their predictions for the Pluto system. I think it could be fun.

[Herobrine]

@fred_76 At what point do those formulae cease being reasonable approximations? You have an asymptote to infinity on the day of the flyby.

[machi]

Pluto+Charon today, magnified 2.5×.
EDIT: Added colorized version.

Attached thumbnail(s)

 

[fred_76]

@fred_76 At what point do those formulae cease being reasonable approximations? You have an asymptote to infinity on the day of the flyby.

In fact there are two things :
1) the approximation of the inverse tangente atan x ~ x because the diameter of the planet by far smaller than its distance from NH,
2) the asymptote you talk about

In practice, those formulae are quite valid until a pair of hours before "contact" as NH travels at 46500 km/h which is >> planets dia.

[Habukaz]

Trying to compare one of the raw images from today (rotated only first from left, rotated and interpolated scaling second from left) with two deconvoluted releases from 8 June and 15 June (respectively):

[fred_76]

Nix and Hydra viewed the 29th june's bin x 1 images. Kerberos still not visible.




Fred

[JRehling]

Thanks, fred_76. This is a good way to convey the progression.

It's particularly poignant to see that 3-days-out image, because that's the best view we'll get of the anti-encounter hemisphere (AEH).

However, I'll point out that the Moon is about 1.5x the size of Pluto, so while Pluto will appear that *size*, we'll see Pluto at 1.5x the resolution that those Moon photos show. Consequently, we'll see the AEHs of Pluto and Charon at the same resolution as your left 2-days-out image of the Moon.

It's quite evident there that Tycho is a crater and one could surmise that Copernicus is. Otherwise, one could interpret the features in comparison to the better imagery of the other hemisphere, but on its own, it's still quite murky. The spectral imaging will add a lot, so that units on the AEH can be identified as likely similar to corresponding features on the encounter hemisphere.

The Charon-shine imagery may fill that in wonderfully, though, and even more important, give us a look at the winter pole that won't otherwise be seen at all.

The data set will basically be a tale of three Plutos: The encounter hemisphere, the anti-encounter daylight "hemi"sphere, and the winter pole. Similar for Charon, but we will only see its winter pole in Plutoshine from 3 days out, so we'll only get albedo/spectral information at very low resolution. On the other hand, Plutoshine is 4x brighter than Charonshine.

As a reminder of "shine" imagery, here's Iapetus in Saturnshine.
http://www.nasa.gov/mission_pages/cassini/...a/pia06168.html

Saturn is, of course, a hell of a lot bigger and brighter than Pluto or Charon, but it's also 200 times farther from Iapetus than Charon is from Pluto, so Charon occupies ~2x the area in Pluto's sky that Saturn occupies in Iapetus'. So Charonshine on Pluto is only a few times dimmer than Saturnshine on Iapetus.

[Mercure]

I was born the same year Voyager visited Neptune, so this is the first of this sort of brand-new-world flyby* in my lifetime. It's super exciting!

So you won't remember how we saw Neptune on rasterized photos in the newspaper. Earth has changed a lot since those summer days of 1989, amazingly by now letting all of us have a front-row seat to, and be part of, space exploration. Thanks UMSF!

[fred_76]

@JRehling : I Know the moon is bigger than Pluto, therefore I redimensionned it's image so that it has the same size as Pluto, when views from the same distance.

Now, for sure, as Pluto is certainly not made from the same materials as Moon, it's aspect will be different.

[JRehling]

Ah, sorry, Fred - I misread! My fault. And I'm doubly sorry, because that means the resolution will be 2/3 of what I'd thought.

The Moon seems, to me, to be unusually hard to interpret in its full phase. A lot of worlds, like Io, seem to look pretty good when full, but the Moon becomes a smear of maria, highlands, and rays. I hope Pluto is easier to make sense of in those distant, full images.

[Phil Stooke]

Io may look pretty good when full... but it sure wasn't easy to interpret!

I think the difficulty in interpreting the Moon at small phase angles (full or nearly so) is repeated for all worlds, notably in recent times Ceres and now Pluto. When Ceres looked twice as detailed as Pluto does today, we had interpretations of giant rifts and canyons on this very forum. Only resolution saves us.

Phil

[Bjorn Jonsson]

Here are the 2015-06-29 05:03 images. This is a stack of three images enlarged by a factor of 4. Two images were also obtained 6 minutes earlier that I could have added to the stack but the resolution is now probably high enough for Charon's changing position relative to Pluto to possibly have become a minor problem without correcting for it (but I notice that machi used them successfully). This image is also a 'milestone' of sorts because the size of Pluto (and the distance in pixels between Pluto and Charon) is now so big that from now on I will probably post images enlarged by a factor of 3 (or smaller) instead of 4.



And this is Pluto with a lat/lon grid:



This reveals that the pole may be close to the center of terrain that is slightly darker than the terrain farther from the pole. This is a somewhat tentative result though.

Charon's shape looks slightly irregular here (and also in machi's version), probably for the same reasons that Pluto looked slightly irregular at lower resolution (Pluto now appears perfectly spherical).

[machi]

Here is slightly improved version. It's now made from 5 stacked images (previous was made from 4) and it's corrected for Charon's motion so Charon is now sharper.
BTW, darker area around Pluto's pole is almost certainly real feature because it's visible also in previous set from 28. June.

Attached thumbnail(s)

 

[jgoldader]

These last few images remind me of Titan, sans atmosphere.

[Daniele_bianchin...]

These last few images remind me of Titan, sans atmosphere.

Probably-stupid quedtion, There are possibilty that the Black Long feature are a metane or azote liquid lake?

[Explorer1]

Still too early to tell (17 million km to go!). If these images were coming out in a newspaper, I would not be taking a magnifying glass to them and exclaiming that Pluto is made of tiny coloured dots!

Two weeks left....

[jgoldader]

Probably-stupid question, There are possibly that the Black Long feature are a metane or azote liquid lake?

Too cold, I think. Wolfram says methane's freezing point is around 90K and Pluto's colder than that. At least, it is today. But the bright and dark regions on the latest Pluto images reminded me of the bright highland and dark lowland regions (probably wrong nomenclature) on Titan. If we see something like that on Pluto, that would be very interesting indeed.

[nprev]

Daniele, I don't think that it's possible for those to be methane lakes since Pluto's atmospheric pressure is far, far lower than even that of Mars; around three micro(not milli-)bars per this NASA fact sheet.

[Decepticon]

I remember a day when triton was theorized to have lakes of methane.

Ciao!

[eliBonora]

One stack of yesterday images (full 400%)
I cannot wait to focus on these features!

[Gladstoner]

The dark features may be more akin to those visible on Triton:

http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA00329

[ZLD]

Well, I was hopeful that all of the June 29 images could be stacked but I think there is actually enough movement that it degraded the quality too much for my liking.


Single frame on left, blink animation on right

June 28, 2015 - 2 images


Charon is absent in one of the images and so I simply excluded it.

June 29, 2015 - 04:56 UTC - 2 images


June 29, 2015 - 05:02 UTC - 2 images



June 29, 2015 - 05:03 UTC - 1 image


Keep in mind these are all limited data stacks so noise is likely to be apparent and different features are also likely to pop in and out of visibility.

[alk3997]

I thought I would see if I could tease some information out of the dark areas using a single image of Pluto/Charon. The original is the 6/29/15 at 05:03:10 UTC 1:1 bin image released today.



No stacking on this one. The only processing was a 4x enlargement followed by contrast/brightness/midtone enhancements.

If anyone would like to speculate about clouds the wispy area near Pluto's dark band certainly could be a starting point or it could be ice. Charon's anti-dark pole almost looks like it has some relief showing.

Anyway, just an attempt to find more information from the data (that will hopefully be obsolete within a week).

When we get images this quickly from New Horizons, it very much reminds me of watching Dr. Albert Hibbs and his guests at JPL explain Voyager images as they appeared on the monitors in real time during the Saturn/Uranus/Neptune encounters.


Andy

[Explorer1]

When we get images this quickly from New Horizons, it very much reminds me of watching Dr. Albert Hibbs and his guests at JPL explain Voyager images as they appeared on the monitors in real time during the Saturn/Uranus/Neptune encounters.

Andy

Will there be anything like that during the NASA TV coverage during the week of the flyby (i.e. seeing mission control)? I've read Emily's blog post but it seems like it will be a combination of press conferences and hammering refresh on the raw images page, not that that's a bad thing....
(Speaking of which, some dedicated Hydra targeting has started: http://pluto.jhuapl.edu/soc/Pluto-Encounter/index.php )

[nprev]

Refer to the first post of this thread, and esp. to Emily's article about planned activities. The data rate from Pluto's distance is nowhere near as high as it is during a Jupiter encounter (1kb/sec vs. something like 38 kb/sec), so we're likely gonna see just a few images with a good deal of time between them on encounter day. Per Emily's article again, only 1% of the acquired science data will be returned then.

[Explorer1]

Yep, I know how slow it will go considering how thin the data-pipe is over these distances. Just wondering about the coverage itself, beyond the critical 'beep' on the 14, all the live reactions from MC (which I'm such a sucker for!)


Also: SOFIA's observations got some good data: http://www.sofia.usra.edu/News/news_2015/06_29_15/index.html

[ZLD]

Best I can do with the June 29 data. I think temporal blurring is subtle but likely problematic at the same time, even at this distance.

[fred_76]

Nix and Hydra the 29/06/2015 in the bin x1 images :



Close up on Pluto and Charon :



It seems there is a huge impact crater on Pluto...

Fred

[Explorer1]

We can't be seeing a crater shadow yet; NH is still at a tiny solar incidence angle until nearly closest approach; it's 'only' a dark patch (see the previous thread, with Bjorn's illustration).

[Habukaz]

The dark features may be more akin to those visible on Triton:

http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA00329

In those images, the dark band near Triton's equator looks a lot like the dark bands near Pluto's equator; though it appears to be somewhat brighter on Triton.

It seems there is a huge impact crater on Pluto...

In rotation videos, the shape looks wrong; too oblong.

We can't be seeing a crater shadow yet

It could though be possible to see different surface composition due to altitude - i.e. like mountains on Earth may have a white snow cover.

[fred_76]

However, the light coming from the Sun (the area facing the Sun is shown with the yellow dot) is quite correct to explain a potential crater rim illumination on the southern hemisphere of Pluto :

[4throck]

Here's my take on the 6/29 images.
5 image stack with unsharp mask, minimal level manipulation, to preserve the overall albedo variations.
I think that the pole shows up nicely this way, and the rest of the details are quite convincing.
Not that different from the other versions posted here, I guess that's a good thing :-)

[pitcapuozzo]

Probably-stupid quedtion, There are possibilty that the Black Long feature are a metane or azote liquid lake?

Here are the phase diagrams of methane and nitrogen. As you can see, both are stable only as solids in Pluto's conditions (T = 35-55 K [-238 to -218°C], 10-20 microbar [0,00001-0,00002 bars])

Attached thumbnail(s)

 

[JRehling]

I don't think *anything* endures as a liquid at pressures as low as Pluto's, at least nothing that's likely to exist in reasonable quantity at Pluto.

Interestingly, hydrogen and neon are liquid at Pluto's temperatures and 1 ATM. Maybe there could be underground liquifers of those, but they'd probably be in tiny abundance unless something has broken down a quantity of H2O. I doubt if we're going to see any signs of present liquid anywhere on Pluto, but some past impact/geological events may have left signs of melting behind. As I noted earlier, Charon may be even more likely to show this.

[Habukaz]

Excerpt from a blog post on the potential for liquids on Pluto:

After Jeff Moore's talk, Jeff Kargel stood up and suggested that liquid nitrogen or neon could potentially flow across Pluto's surface, at least at some times of its year. Then Will Grundy pointed out that nitrogen ice is "a fantastic insulator," so even if liquid nitrogen doesn't flow on the surface, it's quite conceivable that it could be flowing not very far down below the surface. If it's not very far down, it wouldn't take much for some other process to excavate those deposits and make them visible from space. Alan Stern pointed out that impacts on Pluto would happen at 1-2 kilometers per second and would be expected to "locally fluidize" the nitrogen ice. Then Bill McKinnon said that if the impact is big enough, it could briefly increase Pluto's atmospheric pressure and you could have an episode of global nitrogen rain.(!)

[pitcapuozzo]

Alan Stern pointed out that impacts on Pluto would happen at 1-2 kilometers per second and would be expected to "locally fluidize" the nitrogen ice. Then Bill McKinnon said that if the impact is big enough, it could briefly increase Pluto's atmospheric pressure and you could have an episode of global nitrogen rain.(!)

That's how we think Charon could have a transient atmosphere (other than the N2 escaping away from Pluto that it briefly intercepts). Impacts so far away from the sun happen much more slowly than in the inner solar system (1-2 km/s maximum, as Stern stays), and it would be possible for some of them to lift volatiles in the air and make a transient atmosphere around Charon. Stern and Gladstone calculated that Charon is hit by a 1-km KBO approx. every 10^6 yrs, and that such a transient atmosphere would last 10^4 yrs (as an upper limit value).

A few months ago, Gladstone told me: "Apart from the tenuous atmosphere Charon will intercept from Pluto’s escaping N2, the chances of Charon having an atmosphere during the New Horizons flyby are pretty small (but we may be surprised!)"

[neo56]

Here is my take on LORRI pictures taken on 28 and 29 June.





I'm enjoying holidays to catch up my delay on New Horizons photo processing So far I processed pictures from 23 to 29 June.

[Herobrine]

Since all the cool kids are doing it, I took a crack at bringing out features from the 5 LORRI images from 29 June. I opted not to do any deconvolution, to ensure I wasn't inventing features. I'm reasonably confident that any apparent features in these images are real and not artefacts. The result is more-or-less consistent with what has already been posted, but represents one more unique approach that indicates the same features.
Note: Probably best to ignore Charon here, as I aligned the images on Pluto (to 1/8th of a pixel). Charon moves by a noticeable amount between the first and fifth images due to its distance from the barycenter and I've done nothing to correct that movement.

[Phil Stooke]

My stack of June 29th images. Charon's position was adjusted to correct for any movement. No deconvolution is done here.

Phil

[jgoldader]

Downlink ongoing at present, 1kbps. Maybe images later tonight.

[ZLD]

Looked into how much Pluto moved over the course of the course of 6 minutes and decided it wasn't probably enough to fudge too much detail so I had another go.

Much better this time around.




(click to animate)

I wouldn't probably trust the appearance of Charon. It does move a fair bit in 6 minutes and I did not correct for that in any way. Probably why It looks kinda oblong.

[pitcapuozzo]

New Horizons has performed its last TCM (Trajectory Correction Maneuver) before Pluto Flyby.

Stats: third Pluto-approach TCM, sixth TCM since 2006
Date: 3:01 am UTC, June 30th / 11:01 pm EDT, June 29th / 5:01 am CEST, June 30th
Delta-V: 27 cm/s (0.97 km/h)
Delta-T: 23s
Spatial correction: 184 km
Time correction: 20 seconds late
First TCM telemetry: 9:10 am UTC, June 30th / 5:30 am EDT, June 30th / 11:30 am CEST, June 30th

Source

[Gerald]

"OpNav Campaign 4, LORRI 1X1", update of animated gif until 2015-06-29, 27 frames:

Individual frames have been obtained by registering/stacking/cleaning/"dark frame subtraction" of image sets; the resulting frames have then been registered to (faint) background stars as a common reference for the animation.

[pioneer]

Neat. I was wondering if anyone was going to create an approach animation with the latest LORRI optical navigation images.

[nprev]

Here's the official release re today's TCM.

So does this mean that rings and other potentially hazardous debris have been definitively ruled out? According to the 15 Jun update the final analysis was to be completed on 25 Jun, but there doesn't seem to be any announcement of that happening on the site.

[stevesliva]

So does this mean that rings and other potentially hazardous debris have been definitively ruled out?

How wide do you want your error bars?

[ZLD]

How wide do you want your error bars?

As I understand the situation with debris is that it is likely to be in the system but the 4x4 binning should have been able to detect anything that they could avoid but not necessarily much smaller particles. Still haven't seen anything suggesting clouds of debris but we can't easily see the rings of Jupiter on the sun facing side either. It'll probably be fine.

[Gerald]

Debris should be correlated to the presence of additional satellites.
Since we can now distinguish Kerberos, and sometimes Styx in the lossy version of the 4x4 images, those potential smaller satellites should be detectable down to about 1/16 the brightness of Styx/Kerberos or even below by analysing the lossless images. Sensitivity close to Pluto/Charon is maybe not quite as good, due to scattered and reflected light in the LORRI optics, pixel bleeding, and some frame transfer smear.
Detection of small satellites is also dependent of their orbit. Satellites on circular orbits, coplanar to Charon's, are more likely to be detected than satellites with highly inclined, eccentric orbits. Satellites on resonant orbits are particularly likely to be detected, since simulations show where to look for.
Then two analysis results need to be distinguished: Evident or definitive detection of a satellite in the sense of a discovery, and evident non-detection of a new satellite or a ring in the sense of absence of hazards above a given probability.

The latest of these "Search for sources of hazardous material" series, available thus far, are of 2015-06-26.
Accurate analysis and preparation of an official statement takes time.

[pitcapuozzo]

I was wondering, just how old could the surface of Pluto be? I mean, it is tidally locked with Charon, so the lack of tidal heating should make it a pretty inactive world, right? That would make me think its surface should be pretty old. But on the other side, with all that sublimation action going on between atmosphere and surface (I even read something about "sublimation winds") and material exchange between Pluto and its moons (I recently read a paper about that), Pluto would seem a pretty dynamic world. So, do we expect its surface to be young, old or whatever in between?

[craigmcg]

One tidbit I liked from the AMA session yesterday was that at some point they might adjust the spacecraft clock in order to deal with uncertainties in Pluto's position. I assume that is partially because it's a low-risk, low-bandwidth change, and also because the biggest uncertainty is along the radial axis?

[Mercure]

https://www.reddit.com/r/IAmA/comments/3bnj...s_new_horizons/
(Link to the recent Reddit "Ask me anything"-session by the New Horizons team)

[pitcapuozzo]

One tidbit I liked from the AMA session yesterday was that at some point they might adjust the spacecraft clock in order to deal with uncertainties in Pluto's position. I assume that is partially because it's a low-risk, low-bandwidth change, and also because the biggest uncertainty is along the radial axis?

(I hope I understand the question correctly) they are doing so because after July 4th they can't perform any new maneuvre with the propulsion system, so if the find they're a bit late or a bit early compared to the planned trajectory, they are simply going to move the science sequence in time instead of moving the spacecraft in space.

[pitcapuozzo]

So, we have methane! Not that we didn't already know that, but an important proof that the instruments are working as desidered. Also, an important test of Alice, the spectrograph which will observe the Pluto-Sun and Charon-Sun occultations.

http://www.nasa.gov/feature/new-horizons-u...-sunrisesunset/

[4throck]

Also nice approach animations on that link!

[Phil Stooke]

This is a composite of all the different versions of the June 29th images posted here. We all have different processing methods, so this is averaging them, hopefully to reduce processing artifacts.

Phil

[dudley]

The very large feature that resembles a crater appears to be at least 1/2 of Pluto's diameter. Wouldn't an impact of that size have destroyed the integrity of the planet and erased all traces of itself? Does this consideration rule out an impact crater as an explanation of this feature?

[alk3997]

The very large feature that resembles a crater appears to be at least 1/2 of Pluto's diameter. Wouldn't an impact of that size have destroyed the integrity of the planet and erased all traces of itself? Does this consideration rule out an impact crater as an explanation of this feature?

Still too far away and too much image processing to say this is a crater. It could be albedo differences that your eye/brain forms into a crater.

As to your question, how does a methane crater form in these temperatures? I don't know how much strength is provided by methane at very very cold temperatures.

[Habukaz]

Pluto during a rotation that is close to a full one from the deconvolved release:



Compare Pluto to Triton in these images:




Compare the zig-zag dark border on Pluto to the dark border on Triton. Triton's dark border seems less sinuous, but given that both borders are pretty close to a pole in summer...maybe they are related. I thought Pluto looked ridiculously much like Triton when I first saw those frames in the animation (Triton's border looks more sinuous in some of these images).

[Phil Stooke]

That is a very useful comparison. Thanks for posting it.

Phil

[MahFL]

July 1 pics down :

http://pluto.jhuapl.edu/soc/Pluto-Encounter/

[EDG]

I was looking at the latest pic from NH at:

http://pluto.jhuapl.edu/soc/Pluto-Encounte...sure=150%20msec

and I spotted two little dots (at 10:00 and 7:00 positions relative to Charon) - are those two of the smaller moons? I did a bit of histogram stretching around the dots to enhance them a bit, but haven't done anything else to the image.

[Habukaz]

Finally feels like we are in flyby mode. The latest pics are really awesome.

Deconvolved release from 25 June vs. raw image from today:



(the deconvolved frame is darker in the upper part and the black band there is thicker; the comparison was quickly and not carefully made (!))

[volcanopele]

Hydra and Nix are visible in the full-frame mode images from July 1:



I've also summed the three "Hydra" images, enlarged by 200%, and rotated so that Pluto north is up:

[Nafnlaus]

Wow, hardly even needs processing any more...

http://pluto.jhuapl.edu/soc/Pluto-Encounte...sci_1.jpg"" target="_blank">Image link

Even the raw images are getting impressive.

[Nafnlaus]

Manually stacked and unsharp mask'ed

Attached thumbnail(s)

 

[fred_76]

Nix on the bin x1 images of the 1st July :

[neo56]

My take on pictures taken on 29 June at 23h07 UTC and today 1st July at 4h14 UTC:

[JRehling]

I was wondering, just how old could the surface of Pluto be? I mean, it is tidally locked with Charon, so the lack of tidal heating should make it a pretty inactive world, right?

Pinning down the history of tidal heating/interaction for an unknown world is totally impossible. Variables describing how the internal structure reacts to tidal stresses are not only unknown for Pluto and Charon, we don't even know those things for Venus and Mars. What was the initial state of the system: Was Charon in a highly elliptical orbit that required tremendous energy to circularize, or was it pretty circular in the first place? We have no idea. (Well, we have some idea, but not very precisely.) So we have no idea how much energy was converted to heat, or at what rate it was converted to heat. Nor have we seen any close analogues to this system.

It's not yet understood exactly why Enceladus has thermal heating altering its surface into recent times and, say, Dione, does not, nor why the southern hemisphere of Enceladus monopolizes all the activity while the northern hemisphere is ancient. So when we don't understand worlds that we've imaged very well, forget about predicting the internal history of un-seen worlds with any accuracy.

Some things about Pluto's atmosphere are a bit clearer, but only a bit. Certainly seasonal changes have the ability to deposit/remove thin layers which are optically observable, and there's been data to that effect for many years now.

[FOV]

Pluto and Charon:

Pluto: Charon:

Getting more difficult to process both Pluto and Charon together in one image. And yeah Pluto and Charon are getting big enough in the LORRI images to see features clearly, no processing required. On to spotting Nix, Hydra, Styx, Kerberos.

[Julius]

The Pluto system is really coming into view now. It is still surprising even thou it was mentioned before, to see the sharp contrast between light and dark surfaces on Pluto.

[Mercure]

Weirdly, the closest visual match to these last images of Pluto & Charon would actually be the Earth and the Moon, what with Plutos clear delineation in dark and bright areas and Charons more uniform greycard albedo surface (excepting the Pole).

[Alan Stern]

Weirdly, the closest visual match to these last images of Pluto & Charon would actually be the Earth and the Moon, what with Plutos clear delineation in dark and bright areas and Charons more uniform greycard albedo surface (excepting the Pole).

Indeed. We've been occasionally discussing the same on the NH science team the past couple of weeks. That is an old analogy for this system and it applies in other ways (e.g., Earth--like Pluto--also has the volatiles, the color, and the atmosphere; Charon--like the Moon--has none of those).

[ZLD]

Hey Alan, since you are on, do we have any other colors than orange through MVIC as of today? Or is that supposed to be a surprise?

Edit: And... he's off. Oh well.

[machi]

Processed images from 29.6. and 1.7. Magnification 2.5×.
B&W and colorized version.

Attached thumbnail(s)

 

[Herobrine]

Weirdly, the closest visual match to these last images of Pluto & Charon would actually be the Earth and the Moon, what with Plutos clear delineation in dark and bright areas and Charons more uniform greycard albedo surface (excepting the Pole).

Plot twist:

[JRehling]

Processed images from 29.6. and 1.7. Magnification 2.5×.

Are we seeing a specular glint between the center and the limb?

Maybe it's wishful thinking.

[Explorer1]

http://www.nasa.gov/press-release/nasa-s-n...course-to-pluto

All clear confirmed! No debris, so no further TCM needed.

[machi]

Are we seeing a specular glint between the center and the limb?

I have no idea. As it's based on the processing of 5 images, it can be easily remnant of some DCT compression artifact.
But Triton has few smooth frozen plains/lakes so we can expect many interesting things (it's already magnificent view!).

[Gladstoner]

If there was a specular reflection, where would it be on the disk?

[pitcapuozzo]

Damn, these evenly spaced equatorial dark patches are on the opposite hemisphere, the one that will set over the horizons at P-3 days.

http://www.nasa.gov/feature/new-horizons-c...-that-fascinate

[Phil Stooke]

True, but don't forget we will still be able to see half of it at P-1.5 days.

Phil

[Bjorn Jonsson]

Specular reflections are very unlikely in my opinion, also they would be more likely to be visible at high phase angles.

Here is my version of the 2015-07-01 images, a stack of 5 images. For the first time I stacked Pluto and Charon separately using the 2015-07-01 04:17:10 image as reference. The image is enlarged by a factor of 3. The details in this version of these images are consistent with the images already posted here.



Now the resolution is improving rapidly, there is a big difference from the June 29 images. It is now pretty clear that the dark terrain isn't continuous around Pluto's equatorial region and there are now also clear hints of bright terrain south of the dark terrain. Since the dark terrain now covers several pixels in the original JPGs it is now possible to measure its brightness more accurately than earlier. The bright terrain is ~3 times brighter than the dark terrain. Pluto's 'dark' polar cap is very subtle in the original JPGs but it is defnitely visible there. Pluto is now starting to remind me more of Triton than it did 1-2 weeks ago.

Charon is looking steadily more interesting and is now as big in the images as Pluto was in mid-June. The large dark markings in the processed images are real and there are possible hints of an irregular light-dark boundary.

[pitcapuozzo]

True, but don't forget we will still be able to see half of it at P-1.5 days.

True. Plus, they all seem alike, so we really just need to see one to see them all. However it would be interesting to see the space in between, if it's something like a geological boundary (ridges etc) or not.

[Bjorn Jonsson]

Here is a very early and very quick and dirty attempt to do a map of Charon. This is from the June 27 and 29 and the July 1 images. The map is extremely crude but at least this is a starting point. There are at least two features here that are definitely real: The dark north polar region and the dark area farther south near the right edge of the map. Longitude 0 is at the left edge of the map.

[Phil Stooke]

One for the history books! (history of planetary cartography books anyway).

Phil