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Unmanned Spaceflight.com _ New Horizons _ New Horizons: Approach Phase

Posted by: MahFL Feb 4 2015, 09:22 PM

The LORRI image release for today is up at :

http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20150204



Posted by: JTN Feb 4 2015, 11:23 PM

QUOTE (MahFL @ Feb 4 2015, 09:22 PM) *
The LORRI image release for today is up at :
http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20150204

Are we seeing a terminator here, or is that an artifact?

Looking at Solar System Simulator (http://solar.apoapsys.com/api/solarsyssim/?tbody=999&vbody=-98&date=1422151260000&month=0&day=25&year=2015&hour=2&minute=1&fovmul=-1&rfov=90&bfov=5&porbs=1&brite=0&showsc=1&showac=1, http://solar.apoapsys.com/api/solarsyssim/?tbody=999&vbody=-98&date=1422328860000&month=0&day=27&year=2015&hour=3&minute=21&fovmul=-1&rfov=90&bfov=5&porbs=1&brite=0&showsc=1&showac=1) I think the terminator's in the wrong place to match the "flat side", but I might be driving SSS wrong (e.g. not attempted to check for SCET/ERT). In any case phase is only 14.1°. And "Pluto and Charon subtended 2 pixels and 1 pixel, respectively" (I guess the larger 'discs' are due to lack of deconvolution). So I guess it's just an artifact of some kind.

Posted by: MarsInMyLifetime Feb 5 2015, 06:17 AM

We need a lot more pixels in order to differentiate a gibbous shape from a true circle. This shape is pretty much an artifact of making a very few points try to approximate a circle. On the other hand, the two are separated by enough pixels that the barycenter of their dance is truly a point in space between them, about 1/3 the distance from Pluto, now very easy to imagine in this gif.

Posted by: john_s Feb 5 2015, 03:08 PM

The apparent shapes of Pluto and Charon at this resolution are still dominated by the LORRI point-spread function, which is slightly teardrop-shaped, giving that gibbous appearance. It will be another month or two before we see the true shape of Pluto, and then Charon a little later. Can't wait!

John

Posted by: Bjorn Jonsson Feb 7 2015, 09:50 PM

Even though the resolution is far too low to reveal anything like phase angle or surface markings I decided to check the viewing geometry. At first the results were confusing to me; the reason is Pluto's axial tilt. For the OPNAV on 2015-01-27 03:21:00 it was like this:



Pluto's north is down since its axial tilt is ~120°. This is a bit confusing (should one display future images that show some details with Pluto's north up or down?).

The orientation of the 2015-01-27 03:21:00 OPNAV isn't like this. Here is a view from the Solar System Simulator at the time of the OPNAV. Here north is also down:





Posted by: jgoldader Feb 8 2015, 04:20 AM

QUOTE (Bjorn Jonsson @ Feb 7 2015, 04:50 PM) *
Pluto's north is down since its axial tilt is ~120°. This is a bit confusing (should one display future images that show some details with Pluto's north up or down?).


Right-hand rule or bust!

Posted by: elakdawalla Feb 8 2015, 08:45 PM

For painful detail on the issue of Pluto cartography, http://www.planetary.org/blogs/emily-lakdawalla/2013/07301442-plutosci-zangari-cartography.html or her http://www.sciencedirect.com/science/article/pii/S0019103514005971 (which is open-access).

Short version: there is much confusion in the literature about whether north is north or south of the ecliptic, and whether longitude increases east or west; the recommendation is to use right-hand rule going forward, but beware that the New Horizons planning software does *not* use this convention, although JPL Horizons does.

Posted by: Bjorn Jonsson Feb 8 2015, 09:33 PM

I had forgotten about this blog entry - thanks for pointing it out. I'm a bit relieved to know that I'm not the only one that is confused!

Posted by: alk3997 Feb 9 2015, 05:54 PM

It's just too soon to see any detail. In the original non-enhanced image, Pluto is only 2 pixels in size and Charon is 1 pixel wide. Luckily time will fix that.

Looking forward to the 4x4 binned images. Hopefully those will be released this week or next. Resolution won't be better but sensitivity will be. It will be interesting to see Nix & Hydra orbiting Pluto/Charon.

Andy

Posted by: alk3997 Feb 12 2015, 09:36 PM

New Pluto/Charon animation available from end of January:
http://www.nasa.gov/content/the-view-from-new-horizons-a-full-day-on-pluto-charon/index.html#.VN0cuvnF98H


Posted by: jasedm Feb 17 2015, 07:01 PM

For those members (and I include myself) who are not entirely au-fait with celestial mechanics, I found http://en.m.wikipedia.org/wiki/Barycentric_coordinates_(astronomy)#Relativistic_corrections very useful in making sense of the Pluto/Charon orbital dance in the latest opnav campaign images. (Scroll up).....

Jase

Posted by: john_s Feb 18 2015, 05:14 PM

QUOTE (alk3997 @ Feb 9 2015, 11:54 AM) *
ILooking forward to the 4x4 binned images. Hopefully those will be released this week or next. Resolution won't be better but sensitivity will be. It will be interesting to see Nix & Hydra orbiting Pluto/Charon.



And here they are: http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20150218

John

Posted by: alk3997 Feb 18 2015, 06:01 PM

QUOTE (john_s @ Feb 18 2015, 11:14 AM) *
And here they are: http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20150218

John


Thank you, John! Changing the attitude of the spacecraft to prevent a digital artifact from obscuring a moon may be a first in the space program. One of many firsts for New Horizons.

Probably a bit too early to analyze Nix and Hydra's surface features, eh?

Andy

Posted by: algorimancer Mar 9 2015, 02:19 PM

QUOTE (john_s @ Feb 18 2015, 11:14 AM) *
And here they are...


What is the object that appears on frames 4-6 (circled in the clipped version of the animation below)? There's a similar object that appears once in frame 7 (circled, with question mark), but in a slightly different location. The object in frames 4-6 clearly seems to be an object moving downwards. Camera artifact? Other known satellite? Random KBO drifting past?



Posted by: john_s Mar 9 2015, 05:24 PM

We noticed that bright spot and looked into it- it turns out that it’s a hot pixel on the CCD that was not corrected by the rather quick-and-dirty processing that went into making that movie. When we go back to the original images, it’s always in the same place on the camera frame regardless of where the camera is pointing, so we know it’s not real. We'll have better processing in future releases.

John

Posted by: peter59 Mar 10 2015, 11:23 AM

It's incredible, from Pluto separates us only one astronomical unit !
The last nine years have passed so quickly, to meet with Pluto remained only a little over one hundred days.


Posted by: nprev Mar 10 2015, 04:47 PM

Alan just announced on social media that the recent TCM was nominal. smile.gif

Posted by: Habukaz Mar 23 2015, 04:11 PM

Now, if I've understood http://www.planetary.org/blogs/emily-lakdawalla/2014/12031700-the-new-horizons-science.html correctly and not made any mistakes, here should be all of the best-of-the-day (and best yet) non-binned NH images taken between 1 Februrary and 12 July with the corresponding estimated sizes of Pluto and Charon in pixels (as viewed with LORRI).

Using 2400 km as diameter for Pluto, 1207 km for Charon and rounding to nearest integer. Green marks the first non-binned imaging session that month.

01.02: 973 km/px - Pluto 2 pixels across, Charon 1 pixel

12.04: 551 km/px - Pluto 4 pixels across, Charon 2 pixels
13.04: 545 km/px - Pluto 4 pixels across, Charon 2 pixels
14.04: 539 km/px - Pluto 4 pixels across, Charon 2 pixels
15.04: 533 km/px - Pluto 5 pixels across, Charon 2 pixels
16.04: 528 km/px - Pluto 5 pixels across, Charon 2 pixels
17.04: 522 km/px - Pluto 5 pixels across, Charon 2 pixels
18.04: 516 km/px - Pluto 5 pixels across, Charon 2 pixels
19.04: 514 km/px - Pluto 5 pixels across, Charon 2 pixels

28.05: 281 km/px - Pluto 9 pixels across, Charon 4 pixels
29.05: 276 km/px - Pluto 9 pixels across, Charon 4 pixels
30.05: 269 km/px - Pluto 9 pixels across, Charon 4 pixels
31.05: 265 km/px - Pluto 9 pixels across, Charon 5 pixels

01.06: 258 km/px - Pluto 9 pixels across, Charon 5 pixels
02.06: 253 km/px - Pluto 9 pixels across, Charon 5 pixels
03.06: 242 km/px - Pluto 10 pixels across, Charon 5 pixels
05.06: 234 km/px - Pluto 10 pixels across, Charon 5 pixels
06.06: 229 km/px - Pluto 10 pixels across, Charon 5 pixels
07.06: 222 km/px - Pluto 11 pixels across, Charon 5 pixels
08.06: 217 km/px - Pluto 11 pixels across, Charon 6 pixels
09.06: 210 km/px - Pluto 11 pixels across, Charon 6 pixels
10.06: 205 km/px - Pluto 12 pixels across, Charon 6 pixels
11.06: 198 km/px - Pluto 12 pixels across, Charon 6 pixels
12.06: 193 km/px - Pluto 12 pixels across, Charon 6 pixels
13.06: 183 km/px - Pluto 13 pixels across, Charon 7 pixels
15.06: 174 km/px - Pluto 14 pixels across, Charon 7 pixels
16.06: 169 km/px - Pluto 14 pixels across, Charon 7 pixels
17.06: 162 km/px - Pluto 15 pixels across, Charon 7 pixels
18.06: 158 km/px - Pluto 15 pixels across, Charon 8 pixels
19.06: 151 km/px - Pluto 16 pixels across, Charon 8 pixels
20.06: 146 km/px - Pluto 16 pixels across, Charon 8 pixels
21.06: 139 km/px - Pluto 17 pixels across, Charon 9 pixels
22.06: 134 km/px - Pluto 18 pixels across, Charon 9 pixels
23.06: 122 km/px - Pluto 20 pixels across, Charon 10 pixels
25.06: 110 km/px - Pluto 22 pixels across, Charon 11 pixels
27.06: 98.4 km/px - Pluto 24 pixels across, Charon 12 pixels
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

Posted by: mcgyver Mar 30 2015, 08:20 AM

QUOTE (Habukaz @ Mar 23 2015, 04:11 PM) *
Now, if I've understood http://www.planetary.org/blogs/emily-lakdawalla/2014/12031700-the-new-horizons-science.html correctly and not made any mistakes, here should be all of the best-of-the-day (and best yet) non-binned NH images taken between 1 Februrary and 12 July with the corresponding estimated sizes of Pluto and Charon in pixels (as viewed with LORRI).

Using 2400 km as diameter for Pluto, 1207 km for Charon and rounding to nearest integer. Green marks the first non-binned imaging session that month.

12.04: 551 km/px - Pluto 4 pixels across, Charon 2 pixels
[...]
03.06: 242 km/px - Pluto 10 pixels across, Charon 5pixels


It is not very clear to me when the "Hubble limit" will be crossed: according to http://www.planetary.org/blogs/emily-lakdawalla/2013/0218-new-horizons-pluto-better-hubble.html the Hubble limit is around 800 km/pixel and Pluto being 3 pixel large, but according to http://www.nasa.gov/mission_pages/hubble/science/pluto-20100204.html, at least 250 km/pixel resolution (pluto ~=10 pixel) can be reached by processing, obtaining these images:

http://www.nasa.gov/mission_pages/hubble/science/pluto-20100204.html

In first case, we would be currently crossing Hubble limit; in second case, we would be going to cross it in June.

Amazing achievements in both cases!

But we'll have to be patient:

QUOTE
* LORRI's detector is 1024 pixels square. Like many modern space cameras, when the camera reads out its detector, it digitizes each pixel as a 12-bit number. they can be zipped up to about 2.5 Megabits without any loss of detail. It takes 42 minutes to return one LORRI photo to Earth [on January 2015; on July/september, communication will be slower]
http://www.planetary.org/blogs/emily-lakdawalla/2015/01300800-talking-to-pluto-is-hard.html


QUOTE
*There are few data downlinks near closest approach, so we will not receive many images in real time. But the ones we get will be great.
*The mission has promised to release LORRI images (higher-resolution, black-and-white) in near-real-time, but not MVIC (lower-resolution, color) images.
*Only 1% of the science data from the flyby will be returned to Earth during the period around closest approach, including images that the mission has selected for their high science value as well as high public interest. They will be releasing captioned and processed versions as fast as their small team can manage.
*The rest of the image data will be downlinked beginning in September, about 2 months after encounter. It will take 10 weeks to download the full data set.
[...]
On September 14, New Horizons will begin downlinking a "browse" version of the entire Pluto data set, in which all images will be lossily compressed. It will take about 10 weeks to get that data set to the ground. There will be compression artifacts, but we'll see the entire data set.
Then, around November 16, New Horizons will begin to downlink the entire science data set losslessly compressed. It will take a year to complete that process.

http://www.planetary.org/blogs/emily-lakdawalla/2015/03101637-pluto-image-expectations.html

Posted by: machi Mar 30 2015, 11:03 AM

Resolution is given by diffraction limit which depends on telescope's main mirror diameter, wavelength of electromagnetic radiation and overall quality of optical system.
For past observations of Pluto by HST's FOC and ACS/HRC cameras resolution was between 610 (FOC in UV) and 1270 kilometers (HRC at 555 microns).


Posted by: Habukaz Mar 30 2015, 11:09 AM

The official word is better than Hubble at some point in May.

https://twitter.com/NewHorizons2015/status/555766844947456000

Posted by: tedstryk Apr 3 2015, 01:52 PM

QUOTE (mcgyver @ Mar 30 2015, 09:20 AM) *
It is not very clear to me when the "Hubble limit" will be crossed: according to http://www.planetary.org/blogs/emily-lakdawalla/2013/0218-new-horizons-pluto-better-hubble.html the Hubble limit is around 800 km/pixel and Pluto being 3 pixel large, but according to http://www.nasa.gov/mission_pages/hubble/science/pluto-20100204.html, at least 250 km/pixel resolution (pluto ~=10 pixel) can be reached by processing, obtaining these images:


McGyver, the difference is between super-resolution processing and the actual resolution of the camera. And since the ACS/HRC channel is long-dead, HST is no longer capable of mapping Pluto (other than hemispheric albedo differences).

Posted by: jgoldader Apr 3 2015, 07:35 PM

IIRC, the image is actually renders of a mathematical model of the albedo distribution on Pluto's surface that was created to match the HST images, which only had a couple of resolution elements across Pluto, not an image constructed from super resolution.

Similar models were made based on the data from the Pluto-Charon mutual eclipses back in the... 80's and early 90's I believe it was. I worked on a different project with Dave Tholen, who authored the occultation papers with Mark Buie (there was an independent take on the eclipses by Binzel). The idea on those maps was to recreate the light curves of the mutual eclipses that were visible due to fortuitous alignment of the system. Charon, for example, would pass over different areas of Pluto's surface, and the brightness of the system would drop a lot if the area was bright, or only a little if the area was dark. Each eclipse basically gave a "cut" across Pluto's surface, and a lot of numerical modeling resulted in a map of Pluto's surface that would yield the observed light curves.

Really cool and clever stuff.

Posted by: Explorer1 Apr 10 2015, 12:10 AM

A pair of briefings coming up next week:

http://www.nasa.gov/press/2015/april/nasa-hosts-briefings-on-historic-mission-to-pluto/

Posted by: Explorer1 Apr 14 2015, 05:07 PM

Presser on now: color images released!

http://www.nasa.gov/multimedia/nasatv/index.html

Posted by: alk3997 Apr 14 2015, 05:50 PM

First color New Horizon's image of Pluto/Charon:



http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20150414

First glance it looks like the lower part of the Pluto image is less red than the upper part. Perhaps that is just an artifact of the image processing or the solar angle?


Andy

Posted by: Explorer1 Apr 14 2015, 05:56 PM

I would be loath to make any interpretations; this still isn't BTH (Better Than Hubble), for now.

Posted by: Habukaz Apr 14 2015, 06:07 PM

With MVIC, Pluto is currently...what, 1-2 pixels across?

Posted by: elakdawalla Apr 14 2015, 06:11 PM

MVIC resolution in that image is 2274 km, just a bit under 1 Pluto diameter.

Posted by: Marvin Apr 14 2015, 06:27 PM

Slightly larger version of the color image, found on Twitter:



Hubble did an amazing job resolving the color and brightness variations of the surface.

In a way, I feel sad. Before Pluto was mysterious, now it has a face. But I'm looking forward to the data to come. smile.gif

Posted by: ngunn Apr 14 2015, 08:52 PM

QUOTE (Marvin @ Apr 14 2015, 07:27 PM) *
In a way, I feel sad.


Well, you have to I suppose rolleyes.gif , and there's no point in me mentioning that there is an ever-increasing number of other mysterious places to think about . . .

But seriously, I remember the same regret being aired in the press at the time of the first moon landings.


Posted by: belleraphon1 Apr 15 2015, 01:26 AM

I am not sad at all. I am elated. We have lost nothing but gained truth. Was born when all the planets were just dots in the sky. Astronomical objects.
Now they are worlds.

And there is no end to this. I joke with my friends that a passion for planets is a gift that keeps on giving. There is no end. Space is BIG.

My grandsons are 8. What wonders will they know when they are my age?

Sigh...

Posted by: Webscientist Apr 15 2015, 09:01 AM

I don't know whether there is a cryovolcanic activity on Pluto or Charon.

I've incorporated a view of Io at the right scale into the the newly released view of Charon and Pluto for comparison.
The image I've used is 200 px wide. Pluto is roughly 27 pixels wide. So, at the same distance (115 million km), Io would be 42 pixels wide (2368 km vs 3644 km).
Remove your glasses for a better idea! smile.gif
Maybe, there are better candidates for the comparison.






 

Posted by: Gerald Apr 15 2015, 10:36 AM

For anyone who missed part of the briefings, here links to recorded versions:
http://www.ustream.tv/recorded/61102696, 02:40:06 - 02:59:58.
http://www.ustream.tv/recorded/61107589, 00:00:00 - 00:38:42.
http://www.ustream.tv/recorded/61118248, 01:40:24 - 02:37:07.

Posted by: Webscientist Apr 16 2015, 11:02 AM

In the new image of the Pluto Charon system released, I've measured the apparent diameter of Pluto along the virtual line (orbital plane?) from Charon to Pluto and the apparent diameter of Pluto for the normal to this virtual line (south pole to north pole?).
I obtain (approximately) 24 pixels for the first figure and 28 pixels for the second figure.
So, the first figure is about 85% of the second figure or the second figure is about 16% higher than the first figure. unsure.gif

Apparently, not perfectly spherical (unless it is an artifact)? related to tidal forces?


Posted by: Phil Stooke Apr 16 2015, 11:14 AM

Unfortunately that image is a gigantic blow-up of an original image where the planet was about one pixel across, so your result is a trifle unreliable. Wait a bit before trying to measure anything.

Phil

Posted by: Webscientist Apr 16 2015, 11:34 AM

Ok, that's a little early I guess.

I've just represented what it might look like if it is squeezed that way and if it looks like Triton.

Here is the result:

QUOTE (Phil Stooke @ Apr 16 2015, 12:14 PM) *
Unfortunately that image is a gigantic blow-up of an original image where the planet was about one pixel across, so your result is a trifle unreliable. Wait a bit before trying to measure anything.

Phil



 

Posted by: 4throck Apr 16 2015, 01:25 PM

Pluto's size is well known. Occultations give you a precise measurement, much better than low resolution images.
From Wikipedia you have 1184±10 km .

If you had an image where Pluto covered ~50 pixels, each pixel would be as large as the 20km error margin.
To refine the measurement you need images with the planet larger than that :-)

Smaller images will tell you very little and be dominated by individual pixel noise.

Posted by: alk3997 Apr 16 2015, 02:59 PM

QUOTE (Webscientist @ Apr 16 2015, 05:34 AM) *
...
I've just represented what it might look like if it is squeezed that way and if it looks like Triton.

...


If I followed Emily's response earlier, the original MVIC image was approximately 2 pixels by 2 pixels for Pluto, or something very close to that. So all of your image reconstruction is based on approximately 4-6 pixels.

Other than large scale color/brightness differences, I'm not sure what you can get from 4-6 pixels.

It's nice work but more based on the algorithm used to enlarge the original image rather than what Pluto looks like.

Andy

Posted by: jgoldader Apr 16 2015, 03:16 PM

QUOTE (Webscientist @ Apr 16 2015, 07:34 AM) *
Ok, that's a little early I guess.

I've just represented what it might look like if it is squeezed that way and if it looks like Triton.

Here is the result:


My guess is the shape is still dominated by PSF, Pluto is not that oblate.

Posted by: Paolo Apr 16 2015, 04:07 PM

slightly OT: I remember seeing an early-80s artistic view of Pluto and Charon where the latter was depicted as non-spherical and asteroid-like. anyone else remembers it?

Posted by: Landru79 Apr 16 2015, 04:17 PM

QUOTE
Webscientist

"Apparently, not perfectly spherical (unless it is an artifact)? related to tidal forces?"


¿Maybe a phase efect?

 

Posted by: Hungry4info Apr 16 2015, 04:24 PM

As has been explained more times by now than should be necessary, Pluto is a pixel across in the original image. It has been blown up quite a bit in the image that we're all looking at. There's no surface or shape information in the image (other than the hemisphere-averaged surface colour). Everything that is being interpreted as such is a result of noise in the image being smoothed out in the process of making the image appear not pixelated.

Posted by: djellison Apr 16 2015, 04:32 PM

QUOTE (Landru79 @ Apr 16 2015, 08:17 AM) *
¿Maybe a phase efect?


NO!

The Sun-Pluto-NH angle is approx 0.316 degrees currently.

It's one pixel - a bit of PSF - blown up massively. That is all.

Posted by: JohnVV Apr 16 2015, 05:21 PM

QUOTE
I remember seeing an early-80s artistic view of Pluto and Charon where the latter was depicted as non-spherical and asteroid-like. anyone else remembers it?

from the 80's ????

i might be wrong but i thought that even when i first saw or read sagsn's "cosmos"
( sept. 1980 )

that the radius was known at least that it was bigger that 1000Km in diameter

Charon ? was discovered in 1978 so by 1980 ? a mass ( very ruff ) and orbit and range for the diameter should have been known for both Pluto and Charon

now for
P2,P3,P4,and P5
these are small
-- Artists concept --
http://imgbox.com/2VWydUMj http://imgbox.com/i8ttA8nG http://imgbox.com/3eHgY8ip http://imgbox.com/SFRwcCgt

Posted by: Paolo Apr 16 2015, 07:27 PM

QUOTE (JohnVV @ Apr 16 2015, 07:21 PM) *
i might be wrong but i thought that even when i first saw or read sagsn's "cosmos"
( sept. 1980 )

that the radius was known at least that it was bigger that 1000Km in diameter


found it! in an old astronomy magazine. it's a David A Hardy painting (and I will not post it here because of copyright and because the caption partly covers the image). in the caption it is mentioned that Charon was quite likely spherical

Posted by: mcgyver Apr 17 2015, 05:31 AM

QUOTE (Webscientist @ Apr 16 2015, 11:02 AM) *
In the new image of the Pluto Charon system released...

That image is almost "fake", this is the raw one:


Found on twitter:
https://twitter.com/elakdawalla/status/588798812791013376

ADMIN: If you read Emily's excellent article, you would know that she processed that image herself based on the released 'blurry' version. It is not the raw image file.
She said: "Just for fun, I've "de-enlarged" the image by reducing its size by a factor of six -- these don't show you the data's actual original pixels..."

Posted by: Webscientist Apr 17 2015, 08:21 AM

The phase angle hypothesis seemed interesting.
But that is clear now. That's not 50%!

We are more talking about light signals than images unfortunately.

I was surprised when I watched the animation of the Pluto-Charon system in January. The light signal of Pluto seemed elongated. Maybe, it is related to the motion of Pluto.

Anyway, we'll get a better idea in a few days or weeks!

For the view of Emily, raw or resized view?



QUOTE (djellison @ Apr 16 2015, 05:32 PM) *
NO!

The Sun-Pluto-NH angle is approx 0.316 degrees currently.

It's one pixel - a bit of PSF - blown up massively. That is all.



 

Posted by: TheAnt Apr 17 2015, 10:41 AM

QUOTE (Hungry4info @ Apr 16 2015, 06:24 PM) *
As has been explained more times by now than should be necessary, Pluto is a pixel across in the original image. It has been blown up quite a bit in the image that we're all looking at. There's no surface or shape information in the image (other than the hemisphere-averaged surface colour). Everything that is being interpreted as such is a result of noise in the image being smoothed out in the process of making the image appear not pixelated.


Indeed & sigh, we're getting the white spot on Ceres things all over again, but now with the entire Pluto system.
Nothing to see here - yet - please move on. tongue.gif

Posted by: alk3997 Apr 17 2015, 02:55 PM

QUOTE (mcgyver @ Apr 16 2015, 11:31 PM) *
That image is almost "fake", this is the raw one:

...


Rereading once again, since that isn't the raw image, it's likely that the raw image of Pluto is 4-6 pixels at most. So, what can you tell with 4-6 pixels? Probably the most important thing is that interpretations will have to wait until June/July, which luckily isn't that far away.

Andy

Posted by: Aldebaran Apr 19 2015, 12:11 PM

I did some rough back of an envelope calculations.

At the current distance from New Horizons to Pluto of 101 million kilometers (and counting), an unaided observer (who hypothetically hitched a ride) would see Pluto as a faint magnitude 6 body with an angular diameter of 4.8 seconds, or a disk roughly similar to that of Uranus when observed from Earth. Coincidentally, Uranus has a similar apparent magnitude of 5.9 when observed from Earth (or from New Horizons for that matter).

It sort of puts it in perspective for an amateur astronomer.

Posted by: JohnVV Apr 19 2015, 03:47 PM

QUOTE
Indeed & sigh, we're getting the white spot on Ceres things all over again,

No kidding !

for the month of April
QUOTE
12.04: 551 km/px - Pluto 4 pixels across, Charon 2 pixels
13.04: 545 km/px - Pluto 4 pixels across, Charon 2 pixels
14.04: 539 km/px - Pluto 4 pixels across, Charon 2 pixels
15.04: 533 km/px - Pluto 5 pixels across, Charon 2 pixels
16.04: 528 km/px - Pluto 5 pixels across, Charon 2 pixels
17.04: 522 km/px - Pluto 5 pixels across, Charon 2 pixels
18.04: 516 km/px - Pluto 5 pixels across, Charon 2 pixels
19.04: 514 km/px - Pluto 5 pixels across, Charon 2 pixels


the darn thing is ONLY!!!!! 4 px across
LESS!!! than Hubble images of 9 px

see
http://www.planetary.org/blogs/emily-lakdawalla/2014/12031700-the-new-horizons-science.html
this is supposed to be a rather SCIENTIFIC forum
( i tend to be way TOO artistic here and I am the one stating the scientific facts ?????? )

Posted by: 4throck Apr 20 2015, 09:30 AM

Second that.

It's an odd recent trend to see discussions going on based only on visual impressions of heavily processed images, disregarding the most basic numerical facts.
This is not some fancy maths, we are talking integer numbers here, stuff like 4 pixels < 9 pixels rolleyes.gif

Posted by: Gerald Apr 20 2015, 11:14 AM

A small simulated excerpt of what you should consider when trying to interprete pixels and subpixels:

Simulated theoretical perfect image, blur by symmetric PSF, blur by asymmetric PSF, pixelation, interpolation, brightness stretch.
I've skipped hot pixels, dark current, CRs, photon noise, possible compression artifacts, etc.

With a sequence of images it's sometimes possible to do some meaningful SR; with a single image you likely run into processing artifacts.

Posted by: Ken90000 Apr 20 2015, 02:18 PM

I don’t want to add to the S/N ration. However, I think part of the issue here is it is not clear in this discussion that New Horizons includes two imaging experiments. All of the great tables I have seen that indicate Pluto should currently extend three or four pixels apply to the LORRI experiment. LORRI includes a huge 208mm telescope and has been imaging Pluto since 2006.

The color Image that everyone is chattering over was acquired with the RALPH experiment. RALPH is a wonderful devise that can create images in color whereas LORRI’s products are in monochrome. However, RALPH’s camera has only 60mm lens that would not be able to resolve Pluto at this distance.

Even if Pluto presented a slim crescent or was as oblate as Eros, it would still occupy one pixel in the RALPH image that has been published.

Posted by: Habukaz Apr 21 2015, 10:12 AM

For something different:

QUOTE
Getting closer! By May we should detect Pluto's smallest moons: Kerberos & Styx. Only Charon, Nix & Hydra seen as yet


https://twitter.com/NewHorizons2015/status/589798138354896896

So I guess from May on the odds are really increasing for discoveries of new moons.

Posted by: MahFL Apr 21 2015, 12:58 PM

New Horizons is now less than 100 million kilometers away from Pluto.

From http://www.yaohua2000.org/cgi-bin/New%20Horizons.pl website.


Posted by: Habukaz Apr 28 2015, 09:34 PM

Media teleconference coming up tomorrow:

QUOTE
NASA will host a media teleconference at 3:30 p.m. EDT on Wednesday, April 29 to discuss recent images returned from the New Horizons spacecraft as it nears its historic July 14 encounter with Pluto. Officials also will provide an update on the timeline and significance of images the mission team will receive in the coming weeks.


http://www.nasa.gov/press-release/nasa-to-hold-media-call-on-latest-images-of-pluto-from-new-horizons-spacecraft

So I guess we could see some new LORRI images? It would be very cool if we could see some actual contrast from large-scale surface variation rather than PSF artefacts.

Posted by: Roby72 Apr 29 2015, 07:29 PM

Images are out !
Details are visible on deconvolved Pluto !

http://www.nasa.gov/news/media/newsaudio/index.html

Thats impressive at this distance !
Anyone could refer the details to the Hubble images yet ?

Robert

Posted by: tedstryk Apr 29 2015, 07:47 PM

New Horizons has started a "raw" image page for Pluto! http://pluto.jhuapl.edu/soc/Pluto-Encounter/

Posted by: JohnVV Apr 29 2015, 07:59 PM

from the 4th frame of the above gif
2015-4-17 03:45 UT
this is a recreation of pluto

---


it "looks close"
BUT!!!
if anyone could think that they can correlate that with the gif????????
without doing MASSIVE light curve analysis
please see the posts dawn thread about teeny tiny images


wait for 30 to 45 days THEN there will be good EARLY images

Posted by: pitcapuozzo Apr 29 2015, 08:03 PM

It's a polar ice cap! (maybe)

http://www.nasa.gov/pluto042915

Posted by: jgoldader Apr 29 2015, 08:25 PM

We're gonna have to stock up on popcorn for the summer! Pluto and Ceres, it's more than we deserve! smile.gif

Posted by: ugordan Apr 29 2015, 08:30 PM

Oh wow, this is getting real!

Posted by: FOV Apr 29 2015, 08:48 PM

Just 4.5 pixels and Pluto is ALREADY juicy! (I smiled when Weaver mentioned "a 10 inch aperture Celestron" in his description of LORRI.)

Posted by: Julius Apr 29 2015, 09:28 PM

Brilliant stuff. Good times ahead.

Posted by: machi Apr 29 2015, 11:51 PM

Fantastic images!
BTW, images are already on par with best images from Hubble (what is exactly what follows from laws of physics and ingenuity of New Horizons operators).

Posted by: Bjorn Jonsson Apr 30 2015, 12:44 AM

This is really impressive, I didn't expect the images to get so detailed so early, even though I knew what Pluto's size in pixels would be when the images were taken. Now we really are almost there...

Posted by: dmg Apr 30 2015, 12:56 AM

Is there an archived audio or video of today's press briefing? I can't seem to find one.

Posted by: anticitizen2 Apr 30 2015, 01:39 AM

I was looking for a recording too, found one on NASASpaceflight, but instead of using up their bandwidth, I uploaded it to youtube.
https://www.youtube.com/watch?v=5nIiJLON9E4

You'll have to look at the graphics yourself, I didn't synch them up to the audio. http://www.nasa.gov/pluto042915

http://forum.nasaspaceflight.com/index.php?topic=4221.msg1366459#msg1366459

Posted by: Hungry4info Apr 30 2015, 01:45 AM

Someone here knows a lot more about this than I and so I am sure I'll be set straight shortly, but given Pluto's large obliquity, would we really expect polar ice caps at this time? (as opposed to them being closer to equatorial latitudes)

Posted by: belleraphon1 Apr 30 2015, 01:51 AM

Observations trump theory.

Posted by: Explorer1 Apr 30 2015, 02:45 AM

There was certainly one (at least one) cap at Triton. I won't be surprised at a large number of similarities between the two over the next couple of months.


Still hardly believe this is actually happening....

Posted by: Superstring Apr 30 2015, 04:02 AM

I agree there may be similarities but one difference is that Pluto's albedo is far more contrastive than Triton's -- only Iapetus has a more varied, global-scale albedo. Since Iapetus's albedo contrast can be clearly divided into two hemispheres, you could say Pluto has the most splotchy surface in the solar system (for lack of a better word, hah).

It'll certainly be interesting to discover why that is and what that kind of variation looks like up close. Something different from Triton is going on for sure.

Posted by: Ian R Apr 30 2015, 05:16 AM

This is my very, very rough attempt to combine all these wonderful new images of Pluto to form a polar-projected view of the polar ice cap (the red line marks the sub-Charon longitude). I've included a tidied and Gaussian blurred version as well as the original stacked frame.



Posted by: Aldebaran Apr 30 2015, 07:13 AM

Incredible images. I found this excellent article in Nature by Alexandra Witze:

http://www.nature.com/news/pluto-may-have-icy-cap-1.17454

It could be Nitrogen ice.

Echoes of Ceres. Is it a Polar cap or not?

Posted by: blueaeshna Apr 30 2015, 10:27 AM

Judging from our experience at Ceres, could it be that the bright areas we are observing now may actually turn out to be rather small upon close approach but appear larger now due to the high contrast?

Posted by: ngunn Apr 30 2015, 10:38 AM

It's only because most of Ceres is extremely dark that such small white spots are able to contribute significantly to its total reflectance. Pluto is much brighter overall than Ceres.

Posted by: Phil Stooke Apr 30 2015, 02:12 PM

A bit premature but too hard to resist...

First, a sequence of those images through a rotation:



And a crude attempt to map the markings. The prime meridian, facing Charon, is in the middle.



Phil

Posted by: Roby72 Apr 30 2015, 04:18 PM

I just calculated that Pluto was only 4.5 arcseconds in diameter when the pictures are shot.
With an 8inch telescope from earth its hard to obtain good images of such a small object (Uranus has about 3.5" or Mars when its far away is around 5")
Okay..NewHorizons has no turbulent atmosphere to conquer - but it has to be hold that stable during the shots !

Extremely impressive results from the New Horizons team !

Robert

Posted by: Phil Stooke Apr 30 2015, 05:14 PM

I have borrowed a map from here:

http://www.boulder.swri.edu/~buie/pluto/hrcmap.html

(Thanks Mark... I hope it's OK)

And added the one I just posted above. The bright spot at 180 degrees longitude (opposite Charon) is common to all of them - muted in the one below mine because that was made from modelling occultations, which only gave data on the other hemisphere.

Phil


Posted by: Phil Stooke Apr 30 2015, 05:30 PM

And this compares the new map with an average of all five of Buie's. There is a lot of similarity. It doesn't suggest gigantic changes since those maps of the 1990s and 2000s.

Phil


Posted by: Gerald May 4 2015, 05:26 PM

Not yet quite sure (with only two processed image quadrupels), could be one of the moons:


Posted by: JRehling May 4 2015, 06:19 PM

Pluto likely has a polar ice cap, an equatorial ice cap, a mid-latitude ice cap, and ice on top of the ice that's on top of other ice. Pluto may likely be mainly ice for many kilometers down.

All we see is the surface, and major albedo differences can pertain to thin covering as well as the composition of the crust. As on Callisto or the dark side of Iapetus, which are mainly dark, but small craters surface the ice underneath.

We have yet to know what's causing the color/albedo differences on Pluto, but a good bet is that the major constituent of the crust, everywhere, is ice. And the mantle, as well.

That said, the sunlit pole of Pluto has been sunlit for about 25 years. It's gotten continuous sunlight longer than any other surface we've seen on almost any other world, including the rest of Pluto. Very, very faint sunlight, but more than most of Pluto has gotten.

Posted by: alan May 4 2015, 06:54 PM

Perhaps more of a frost cap, being formed more relatively recently.

Posted by: elakdawalla May 4 2015, 07:41 PM

QUOTE (Gerald @ May 4 2015, 09:26 AM) *
Not yet quite sure (with only two processed image quadrupels), could be one of the moons:

I tried this exercise with several sets of images (stacking the 5 exposures and aligning on the star field) and I think I can maybe sort of pick out one moon in a few frames but it's really pretty marginal. I decided that this wasn't a very successful exercise. (Click to animate.)


Posted by: ZLD May 4 2015, 08:14 PM

If you take the short exposures and stretch them, you can find a few interesting dots that seem to move. I didn't spend a lot of time searching through images but there do seem to be a fair number that don't stretch cleanly at all. I'd be interested to see if anyone else has done this with more frames though.

The animation includes frame lor_0292751773_0x630_sci_9 and lor_0292546843_0x630_sci_6.


Posted by: Gerald May 4 2015, 08:51 PM

QUOTE (elakdawalla @ May 4 2015, 08:41 PM) *
I tried this exercise with several sets of images (stacking the 5 exposures and aligning on the star field) and I think I can maybe sort of pick out one moon in a few frames but it's really pretty marginal. I decided that this wasn't a very successful exercise. (Click to animate.)

I'm now almost sure, that at least one moon (besides Charon) can be extracted, after more advanced processing (subtracting background stars), and after adding another two sequences:

(follow the red circle)

But I don't know yet, whether it's Nix or Hydra.

Posted by: Julius May 4 2015, 09:28 PM

Would it not be possible to question the hypothesis of an internal ocean on pluto by simply observing the orbits of Pluto and Charon from this distance ?

Posted by: Gerald May 5 2015, 01:18 AM

The Pluto-Charon system is mutually tidally locked, excentricities are low. Therefore orbital changes due to tidal forces are probably low, with little difference for the long-term orbits between a presence or an absence of oceans.

---------

For system clock 0291115627, I could identify a subtle moon candidate, too:


Together with the other four candidates above, here a synopsis of the positions:

The first and the last position (at 0292752227) in the synopsis are almost diametrical with respect to the Pluto-Charon barycenter.
The time difference is 0292752227 - 0291115627 = 1636600 s = 18.942 d.
The orbital period of Nix is 24.856 d, that of Hydra is 38.206 d (according to http://en.wikipedia.org/wiki/Pluto#Near_resonances).
This makes the moon candidate most consistent with Hydra.

Posted by: dvandorn May 5 2015, 03:56 AM

While there does appear to be a bright albedo feature at the visible rotational pole, it's good to recall that this pole has also been pointing at Sol for, what, decades? Instead of being a cold trap that causes ice deposition, this would be the spot of highest insolation (such as it is, out in Pluto space) on this dwarf planet.

Maybe dark ices absorb more solar heating than higher-albedo ices at this sol-pointing pole and are selectively driven off, to re-accumulate on the shadowed side. Leaving the higher-albedo ices behind, and thus showing what looks like a "polar ice cap," even though it's a net deflational, not depositional, feature.

I don't insist on this interpretation, but it fits the observed facts...

-the other Doug

Posted by: Aldebaran May 5 2015, 05:44 AM

Possibly tholins account for some of the darker reddish coloration.

http://adsabs.harvard.edu/abs/2005DPS....37.5502O

Posted by: Phil Stooke May 5 2015, 09:40 AM

"Maybe dark ices absorb more solar heating than higher-albedo ices at this sol-pointing pole and are selectively driven off, to re-accumulate on the shadowed side. Leaving the higher-albedo ices behind, and thus showing what looks like a "polar ice cap," even though it's a net deflational, not depositional, feature."


Verily, dvandorn, Sire, thou mayst be correct in thy supposing. Let us call it, not a polar cap, but a polar tonsure!

Phil


Posted by: elakdawalla May 5 2015, 03:29 PM

http://www.planetary.org/blogs/emily-lakdawalla/2013/09051420-plutos-atmosphere-does-not-collapse.html

Posted by: Gerald May 5 2015, 03:47 PM

Working a little more systematically:
14 five-image sequences of "OpNav Campaign 3, LORRI 4X4" cleaned and "stacked" by adding up the four most similar corresponding pixel values of each of the five images, and subsequently subtracting 112 to make better use of the available grey values:


CRs should be filtered out that way.
Sums larger that 255 are mapped to white, those smaller than 0 (due to the subtraction of 112) to black.

Next intended processing step: accurate registering; I guess, this will take a few days.

Posted by: Gerald May 6 2015, 06:56 PM

Registering of OpNav3 LORRI 4x4 sequence is work in progress, thus far up to about 1 pixel, not yet fully accurate, but sufficient for a tentative identification of a second moon (probably Nix) :
http://imgur.com/b2qI5hb

Posted by: jasedm May 6 2015, 08:28 PM

Very nice work Gerald.

Posted by: Gerald May 7 2015, 05:58 AM

Thanks a lot!

Registering of the 14 cleaned and stacked OpNav Campaign 3, LORRI 4x4, quintuples until 2015-05-01 with good accuracy completed.
Pinhole camera model with assumed infinitesimally small fov angle did the job.

Overview:
http://imgur.com/jkndvXt

Animation:
http://imgur.com/P0gycoc

http://imgur.com/a/SOYAf#0, contained pngs (4-fold magnified) should be of the best quality I can provide thus far.

Next intended processing step is determining starfield and Pluto/Charon(?) background.

Posted by: Gerald May 7 2015, 02:25 PM

Stellar ( + Pluto ) background, median-filtered:
http://imgur.com/FVhG4Xr
(The "Meridian" in the title of the graphics must be a result of lack of sleep. wink.gif )

Subtracting this image from the 14 stacked images sequence, and 8-fold brightness-stretching, results in the following preliminary animated gif:
http://imgur.com/Kg20dR5

The moons get more distinct, but the images can be improved by some more brightness adjustment...

Posted by: elakdawalla May 7 2015, 03:18 PM

That is very nice work.

Posted by: Gerald May 7 2015, 03:37 PM

Thanks Emily! smile.gif

Here some further brightness stretch and adjustment, cropped:



I think, that's now close to the limits of what can be done with "basic" image processing techniques.

Posted by: Gerald May 8 2015, 05:33 PM

False color animated gif of the dancing moons:
http://imgur.com/ji6kw2z
(background blue, very bright variable parts red, subtle objects greenish)

Brightest stars (not too close to Pluto/Charon), and the presumed Pluto/Charon barycenter with crosshairs, cropped:
http://imgur.com/PVWSWdx

Background masked, to show only the above marked stars:



List of star pixel positions in the above graphics, and integrated brightnesses:
 lor_0290526027_0x633_sci_8_etc_cleaned_register_median_data.txt ( 2.98K ) : 311


The brightest object should be close to the presumed Pluto/Charon barycenter.
This position is useful to narrow down the parameter space where to look for other moons, and to pin down the orbital parameters of Nix and Hydra.

Posted by: Gerald May 9 2015, 04:03 PM

Starting with uploads of two processed images to http://nova.astrometry.net/user_images/665843#annotated (and http://nova.astrometry.net/user_images/665870#annotated) following a hint of http://www.planetary.org/blogs/emily-lakdawalla/2015/04291753-new-horizons-sees-surface.html, I've obtained the coordinates of the star background.

CODE
Center (RA, Dec):    (270.678, -14.637)
Center (RA, hms):    18h 02m 42.813s
Center (Dec, dms):    -14° 38' 12.604"
Size:    34.9 x 34.9 arcmin
Radius:    0.411 deg
Pixel scale:    1.02 arcsec/pixel
Orientation:    Up is -159 degrees E of N

Then I've the assembled a blink gif between a map obtained from https://www.google.com/sky/#latitude=-14.642735392952307&longitude=90.69831848144531&zoom=10&Spitzer=0.00&ChandraXO=0.00&Galex=0.00&IRAS=0.00&WMAP=0.00&Cassini=0.00&slide=1&mI=-1&oI=-1 as a reference, and a roughly brightness adjusted version of the filtered and merged OpNav Campaign 3, LORRI 4x4, images (until 2015-05-01):
http://imgur.com/HW722GZ

Besides the bright Pluto/Charon barycenter, I found two subtle, but significant differences:
1 - could be a glitch in the reference map, or a variable object,
2 - unclear, could be a variable star, or a TNO / moon; I can rule out a processing artifact almost with certainty, as well as an incompletely filtered CR hit, since the feature is present in several LORRI images.

Posted by: Fred B May 9 2015, 05:12 PM

Here's my take on moon IDs. Sigma clipped & aligned the last four quints in Maxim DL. No sign of Styx or Kerberos yet but it shouldn't be much longer. Click for animated GIF:


Posted by: Gerald May 9 2015, 05:35 PM

Great!
I get more and more the impression, that Nix and Hydra are rather non-spherical, and rotating.

Posted by: nprev May 9 2015, 11:51 PM

Nonspherical is obviously highly probable for both moons, and of course they're rotating. Be interesting if they're not rotationally locked with respect to Pluto, though, or if there's some sort of odd harmonic relationship as we've seen elsewhere.

Posted by: Paolo May 10 2015, 07:05 AM

speaking of which, are there any ideas of the rotation status of the minor moons? I guess a classical spin-orbit resonance would be difficult to achieve in such a binary system, as it would be like orbiting around a highly non-spherical primary. would a spin resonant with Pluto's spin and Charon's orbit be more likely?

Posted by: Phil Stooke May 10 2015, 07:20 AM

I think a standard spin orbit resonance is still most likely, with perhaps larger physical librations than we are accustomed to. The Saturn system is very complicated, but I think only Hyperion is in an unusual rotation state.

Phil

Posted by: elakdawalla May 10 2015, 04:15 PM

http://www.planetary.org/blogs/emily-lakdawalla/2013/07241850-plutosci-wednesday.html

Posted by: pitcapuozzo May 10 2015, 06:18 PM

QUOTE (Aldebaran @ Apr 30 2015, 09:13 AM) *
It could be Nitrogen ice.


As we understand it, Pluto's surface is a mixture between bedrock and N2, CH4, CO and C2H6 ices cover, plus the atmospheric gasses freezing on the surface (N2, CH4, CO, Ar, higher hydrocarbons (acetylene, diacetylene) and nitriles (hydrogen cyanide, dicyanoacetylene) ), so the situation is much more complex than just simple nitrogen (N2).

Posted by: pitcapuozzo May 10 2015, 06:21 PM

By the way, here is some info on Pluto's and Charon's Sun occultations, in case someone hasn't posted them already.

"For both ingress and egress, far-ultraviolet solar occultations will be observed with the Alice instrument (wavelength bandpass: 52-187 nm) and uplink radio occultations will be observed with the REX instrument (X band wavelength: 4.2 cm), for both Pluto and Charon. The solar and radio occultations mostly overlap in time (since the Earth and Sun are very close together (0.24°) as seen from Pluto); the Pluto occultations are about an hour after closest approach (e.g., we will observe the solar ingress at Pluto from 12:16-12:49 UT on July 14th, and expect the Sun to set at about 12:47 UT; closest approach to Pluto is expected at 11:50 UT). The Charon occultations occur about an hour after the Pluto occultations. Besides all these occultations (we also observe the occultation by Pluto of a bright UV star with Alice, starting about 4 hours after closest approach), we use the Alice instrument to look for “airglow” (a faint glow at certain UV wavelengths, mostly due to processes related to UV sunlight; e.g., a UV photon from the Sun ionizes an N2 molecule, the emitted electron may be energetic enough so that when it hits another N2 molecule it breaks it apart and excites one of the N fragments to emit a photon at 134 nm). The particle instruments will indirectly study atmospheric escape by measuring ions formed when solar wind protons collide with escaping N2 molecules and steal an electron – the N2+ ions are swept up into the solar wind and are called “pickup ions”. We’ll also use the LORRI and MVIC imagers to look for clouds and hazes, or even plumes (as were seen at Triton, a near twin of Pluto)."

From an email conversation I had with Randy Gladstone, atmospheric lead scientist on New Horizons.

Posted by: Aldebaran May 11 2015, 03:04 AM

QUOTE (pitcapuozzo @ May 10 2015, 06:18 PM) *
As we understand it, Pluto's surface is a mixture between bedrock and N2, CH4, CO and C2H6 ices cover, plus the atmospheric gasses freezing on the surface (N2, CH4, CO, Ar, higher hydrocarbons (acetylene, diacetylene) and nitriles (hydrogen cyanide, dicyanoacetylene) ), so the situation is much more complex than just simple nitrogen (N2).


I was talking about the polar ice cap specifically and for what it's worth, I was quoting the article. Solid Nitrogen and Carbon Monoxide are perhaps more likely to be transient. Methane is more likely to be constantly frozen with perhaps a smaller proportion in the lower atmosphere. The remainder including Argon, higher hydrocarbons and of course thiolins would be almost permanently frozen. Hydrogen cyanide would have negligible vapour pressure and may be likely to be found in association with thiolins in more ablated regions, although over time it tends to hydrogenize even in the solid phase. I would add methanimine (CH2NH) to your prospective list.

Either way, a lot of this is speculation, but we only have to wait a couple of months to find out more.

Posted by: Gerald May 11 2015, 11:10 AM

Starting from manually determined positions of Nix and Hydra
http://imgur.com/2plZdJe
in 17 (until 2015-05-06) of the OpNav Campaign 3, LORRI 4x4, cleaned, stacked and star-background-subtracted image quintuples I've tried to simulate the positions by manually adjusting parameters of assumed circular orbits:
http://imgur.com/uNDBlaS
This simulation can be extrapolated:
http://imgur.com/txPaZvC
After narrowing down the orbital plane I've transformed the processed LORRI images, such that objects orbiting in a circular way around the Pluto/Charon barycenter are mapped to almost constant position; phase angle as x, radius as y-axis:
http://imgur.com/IOQMWbx
Here an example of the last eight of this image sequence stacked to reduce noise:
http://imgur.com/kOSBWSi

Versions on less
http://imgur.com/Cs23RIg http://imgur.com/bdr9AeO
and more processed images:
http://imgur.com/fU5k42M http://imgur.com/5zd02sE

For small radii the method is very sensitive to the barycenter.

Nix and Hydra are apparent, Styx and Cerberus not yet evident (to me), despite this excessive processing.

Posted by: pitcapuozzo May 11 2015, 01:35 PM

QUOTE (Aldebaran @ May 11 2015, 05:04 AM) *
Either way, a lot of this is speculation, but we only have to wait a couple of months to find out more.


I agree, it's definitely speculation, but it's not like we can do much more before July 14th biggrin.gif Yes, the purpose of my comment was just to say that reducing it to one element may lead you to misunderstand the broader picture. Your comment is absolutely fine! Plus, like you say, with the few data we have it's impossible to say anything with certainty. Can't wait for July!!

Posted by: Ian R May 11 2015, 01:56 PM

Stellar image processing, Gerald. Really enjoying your work.

Posted by: Fred B May 11 2015, 03:35 PM

I just noticed that the image metadata files have the expected X,Y coordinates of all the objects in each raw image. For example:

http://pluto.jhuapl.edu/soc/Pluto-Encounter/data/pluto/level1/lor/info/029325/lor_0293251947_0x633_eng_1.txt lists:

PLUTO;X=127;Y=126
CHARON;X=128;Y=137
NIX;X=119;Y=99
HYDRA;X=116;Y=156
KERBEROS;X=152;Y=122
STYX;X=107;Y=126

These seem to have the Y origin at the bottom of the image, and I needed to subtract a pointing offset from all of them equally to get things to line up. But this could help with spotting Styx and Kerberos, perhaps doing a manually shifted stack on the expected XY. Strip the URL back to /info/ for a directory of the files.

Posted by: pitcapuozzo May 12 2015, 08:57 PM

Finally, Kerberos and Styx!

http://www.nasa.gov/image-feature/nasa-s-new-horizons-spots-pluto-s-faintest-known-moons

Posted by: ElkGroveDan May 13 2015, 02:26 AM

QUOTE (Ian R @ May 11 2015, 06:56 AM) *
Stellar image processing, Gerald.


Planetary, actually.

Posted by: 0101Morpheus May 13 2015, 10:31 AM

All five this early, awesome.

That is all the known moons down. Now we keep watch for the unknowns (if they exist).

Posted by: Gerald May 13 2015, 03:57 PM

First congrats to the New Horizons team, and particularly to John Spencer and his image processing team, for accomplishing this milestone!
At least with the published jpegs until 1st of May that's exceedingly difficult.

QUOTE (Fred B @ May 11 2015, 05:35 PM) *
I just noticed that the image metadata files have the expected X,Y coordinates of all the objects in each raw image.
... I needed to subtract a pointing offset from all of them equally to get things to line up.


The coordinates seem to be relative to the barycenter of the system.
I tried to adjust for this by adding the displacement needed to register stars:

But there is an increasing error build-up. I've been pondering for a while for the reason; my best explanation thus far is a changing parallax of the Pluto/Charon barycenter with respect to the starfield background during the OpNav Campaign 3.

Posted by: lollipop May 13 2015, 05:19 PM

Is the error build up due to the increasing apparent diameter of the system as NH gets closer between frames?

Posted by: Gerald May 13 2015, 06:12 PM

The decreasing distance (http://en.wikipedia.org/wiki/Radial_velocity) seems to be considered.
My best guess is, that the shift is caused by the http://en.wikipedia.org/wiki/Proper_motion / transverse velocity (applying the astronomical notions for velocities of stars by replacing the solar system barycenter by New Horizons).
For a more accurate modelling the transverse velocity components of Pluto/Charon and New Horizons need to be considered.
Previously I've assumed the transverse velocity as zero/negligible.

Posted by: Habukaz May 13 2015, 09:21 PM

NH raw images (binned) with timestamp today have been released, which is interesting considering the fact that images at these distances have a significant probability of containing hitherto undiscovered/unpublished moons.

Posted by: john_s May 13 2015, 10:33 PM

All the obvious geometrical effects are included in the predictions of the positions of the objects in the images- this is all done with SPICE which knows how to make those calculations. The offsets are mostly because the spacecraft orientation is only determined to within a certain precision, that is bigger than the resolution of the camera, so you can't predict the exact pixel objects will land on from the spacecraft pointing data alone. In fact the first thing we do when analyzing the images is to determine accurate pointing by comparing the star positions to a catalog. I'm not sure why the error would show systematic drifts with time, but it might be just coincidence.

John

Posted by: Gerald May 13 2015, 11:33 PM

It seemed to me to be a drift of the Pluto/Charon barycenter relative to the star background, somewhere near 3e-3 degrees over more than three weeks.
I could imagine a slightly curved trajectory of New Horizons due to the Sun's field of gravity, or an effect of Pluto's orbital motion, or just some glitch in my processing or perception.
But that's just preliminary ideas; I haven't done a fully accurate analysis (yet), and may post a revision later.
(I'm intending to take a look at the hazmat images, first.)

For an accurate analysis of the orbits of the moons, however, it will likely be necessary to determine or rule out the presumed drift.

Posted by: tanjent May 14 2015, 12:42 PM

To a first approximation, the spacecraft and the Pluto-Charon system are approaching each other along the unequal legs of a right triangle, so why shouldn't the barycenter move with respect to the background star field? The barycenter is not the bulls-eye of a stationary target.

Posted by: lollipop May 14 2015, 04:12 PM

I've been straining my brain over tanjent's idea. In rough numbers, Pluto is moving at about 5km/s towards the point where closest approach will occur. NH is moving towards the same point at about 14km/s. Imagining the third side of the triangle as the line joining NH to Pluto, the three sides will shrink in proportion to each other so that the direction of the line joining NH to Pluto stays approximately constant. I say approximately because the paths are curved, they aren't really aiming at exactly the same point etc. Imagining myself riding along with NH, I'm not surprised that Gerald finds a very small drift for the barycentre - the apparent motion of Pluto relative to the background stars as seen from NH would be much less than that seen from the Sun.

Posted by: chemman May 14 2015, 05:13 PM

When I first looked at the new processed images from the NH spacecraft showing the motion of all four of the small moons, I couldn't help but notice that there was a diffuse blob that starts out beside Hydra and is apparent in the last 3 of the frames. Let me just say I understand this is probably just an artifact. But I haven't quite been able to convince myself of this so I started wondering what if it was real. So in the interest of mostly just pure speculation, what if it is an ejecta plume from an impact event on Hydra (I know what are the odds that we would just happen to observe this). I'm not familiar enough with the orbital mechanics of this system to try and say if the apparent motion of the object would even fit such a scenario. Thoughts?

http://www.nasa.gov/image-feature/nasa-s-new-horizons-spots-pluto-s-faintest-known-moons

Posted by: scalbers May 14 2015, 05:22 PM

QUOTE (lollipop @ May 14 2015, 04:12 PM) *
Imagining myself riding along with NH, I'm not surprised that Gerald finds a very small drift for the barycentre - the apparent motion of Pluto relative to the background stars as seen from NH would be much less than that seen from the Sun.

Yes it makes sense to have a small drift from the curvature for NH's and Pluto's paths. This seems consistent with being a few percent of the drift of Pluto in the sky as seen from the sun, given NH's speed relative to Pluto. Unless Gerald is referring to an error in the drift vs the drift itself. If Celestia or similar software has NH added to it, then this drift can be independently evaluated?

Posted by: john_s May 14 2015, 05:42 PM

QUOTE (chemman @ May 14 2015, 10:13 AM) *
When I first looked at the new processed images from the NH spacecraft showing the motion of all four of the small moons, I couldn't help but notice that there was a diffuse blob that starts out beside Hydra and is apparent in the last 3 of the frames.


When you push the image processing as hard as we had to do to see Styx in this sequence, all kinds of artifacts start to emerge- that fuzzy blob is probably some sort of internal reflection. We could have manually cleaned up the release image to remove everything we weren't sure was real, but we decided a "warts and all" release would give a better idea of what the data are really like, and the challenges of working with the images (plus, we don't have that kind of time smile.gif ). We'll have much better images soon, of course.

John

Posted by: alk3997 May 14 2015, 05:46 PM

QUOTE (chemman @ May 14 2015, 11:13 AM) *
When I first looked at the new processed images from the NH spacecraft showing the motion of all four of the small moons, I couldn't help but notice that there was a diffuse blob that starts out beside Hydra and is apparent in the last 3 of the frames. ... Thoughts?


I believe each of the four smaller moons is now 1 pixel wide and was teased out of background noise. The blob you see is much less than the original 1 pixel, so it's just an imaging artifact.

Also don't forget that the spacecraft had a different attitude relative to the Plutonian system during some of these images so the direction of the artifacts may change with each image.

Andy

P.S. Sorry John for the duplicate. I started typing just as you hit send.

Posted by: Gerald May 15 2015, 12:03 AM

Here a stitch of seven 2015-05-11 "Search for sources of hazmat" 6-image stacks:



It has been rather easy to identify Nix and Hydra. But I wasn't able to find Styx and Kerberos. Here a crop of a heavily processed version, obtained by subtracting an appropriately brightness-stretched version of the OpNav Campaign 3 stitch, and in parallel subtracting a processed Google Sky image roughly simulating the LORRI images, then combining the two differences to filter out stars as far as possible:

I've tried several processing techniques, but none was successful in revealing the two smallest known moons of the Pluto/Charon system.
I guess, that the data loss due to jpeg compression and reduced bit depth has swallowed the tiny signal of the two moons.
Some discrepancies (pointed out in some preceeding post) to Google Sky have been reproducible.

Some images of OpNav Campaign 3 aren't yet included in my processing. Might be, that adding the latest images of the sequence, and considering the potential transverse velocity component will add up to a perceivable signal.
I hope, I'll be able to investigate this over the week-end.

Posted by: Gerald May 17 2015, 02:05 PM

"Search for soures of hazmat", stitching by median-filtering, blink gif
http://imgur.com/dK9N7he
and differencing of cleaned and summed images:


Posted by: Gerald May 25 2015, 12:40 PM

Some more elaboration of the presumed parallax:
A two-image blink gif consisting of two cleaned, stacked, registered and cropped OpNav Campaign 3, LORRI 4X4, images, taken with an interval of about 32 days:


I'd say, it shows the parallax of the Pluto/Charon system evidently with respect to the background stars.
The increasing apparent angle between Pluto and Charon is evident, too.

Posted by: Gerald May 25 2015, 03:52 PM

21 sets of OpNav Campaign 3, LORRI 4x4 images, source images and stacked version, synopsis:
http://imgur.com/jeb1wmD

Edit: http://imgur.com/a/wOT3k#0.
Reference point and rotation angle for respective applied (north-south aligned) registration:  metadata_OpNav3_reg_trunc.txt ( 2.06K ) : 290

Posted by: Bjorn Jonsson May 26 2015, 11:09 PM

A few days from now New Horizons will obtain unbinned images that will have almost two times better resolution than the images released in April. In these images Pluto will be a whopping 8 pixels or so across - I may never have been looking as much forward to seeing such tiny images as I'm doing now. These images might even start revealing something on Charon if it has large scale markings.

I decided to assemble a quick montage comparing the best released NH Pluto images so far to several outer planet satellites at low resolution. For the satellites I used Voyager images except at Saturn where I used Cassini images. I used two images of each body. In the best NH images so far Pluto is roughly 8 pixels across following stacking and extensive processing (in the original images it is 4-5 pixels). I decided to make the satellites bigger, about 12 pixels across, mainly because soon we'll be seeing better NH images than the ones released last month. In all of these images where possible the phase angle is comparable to the phase angle in the NH images. I made no attempts to correct the image orientation (i.e. make north up).

This is the result:



Pluto is known to be a high-contrast body. It is obvious from this (with lots of caveats since I don't know the details of the Pluto image processing) that the contrast is rather big but not nearly as big as on Iapetus. The best satellite analogs in terms of contrast seem to be Dione, Ganymede, Io and maybe Ariel. Triton exhibits far less contrast than Pluto. It's interesting to note that Ganymede has polar caps that are brighter than the equatorial regions.

It's going to be really exciting to see the true nature of Pluto's bright/dark markings revealed over the next several weeks.

Posted by: Bjorn Jonsson May 27 2015, 12:08 AM

And here is a version of the above image where I have attempeted to correct for the albedo of the bodies. This is only approximate and should be taken with a grain of salt.





Posted by: Gerald May 27 2015, 05:38 PM

QUOTE (Bjorn Jonsson @ May 27 2015, 01:09 AM) *
I made no attempts to correct the image orientation (i.e. make north up).

In my latest "OpNav Campaign 3, LORRI 4X4" series I've chosen http://nova.astrometry.net/user_images/684200#original (within 0.1 degrees accuracy, most likely according to the J2000.0 system) to stay compatible with http://www.google.com/sky/#latitude=-14.6353138267&longitude=90.671158459&zoom=11&Spitzer=0.00&ChandraXO=0.00&Galex=0.00&IRAS=0.00&WMAP=0.00&Cassini=0.00&slide=1&mI=-1&oI=-1, and to simplify comparison with a generally accepted frame of reference.

Regarding FOV: The new-image.fits (link on http://nova.astrometry.net/user_images/684200#annotated) image header says 1.02179 arcsec/pix (using the https://www.spacetelescope.org/projects/fits_liberator/), that's 1024 x 1.02179'' / 3600(''/°) = 0.29064° fov for 1024 pixels.
(I've submitted an average image, obtained from the 21 cleaned, 4-fold magnified, stacked and registered 4x4 binned LORRI images; the pixel scale is hence for the 1x1 binned images.)

Posted by: Ian R May 27 2015, 07:32 PM

New images from early May have been released!

http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20150527

Posted by: Habukaz May 27 2015, 07:41 PM

Wowzers at the latest images! I made a quick animation with the images closer to native resolution.


Posted by: epoca May 27 2015, 07:45 PM

Does anyone have the specs of the Pluto and Charon occultations that NH will use to study their atmospheres? Not really sure if this is the correct place to ask it, please excuse me and feel free to move them somewhere else if necessary.

Posted by: pitcapuozzo May 27 2015, 07:48 PM

QUOTE (epoca @ May 27 2015, 09:45 PM) *
Does anyone have the specs of the Pluto and Charon occultations that NH will use to study their atmospheres? Not really sure if this is the correct place to ask it, please excuse me and feel free to move them somewhere else if necessary.


Sure.

For both ingress and egress, far-ultraviolet solar occultations will be observed with the Alice instrument (wavelength bandpass: 52-187 nm) and uplink radio occultations will be observed with the REX instrument (X band wavelength: 4.2 cm), for both Pluto and Charon. The solar and radio occultations mostly overlap in time (since the Earth and Sun are very close together as seen from Pluto); the Pluto occultations are about an hour after closest approach (e.g., NH will observe the solar ingress at Pluto from 12:16-12:49 UT on July 14th, and the Sun is expected to set at about 12:47 UT; closest approach to Pluto is expected at 11:50 UT). The Charon occultations occur about an hour after the Pluto occultations.

Besides all these occultations (NH will also observe the occultation by Pluto of a bright UV star with Alice, starting about 4 hours after closest approach), NH will use the Alice instrument to look for “airglow” (a faint glow at certain UV wavelengths, mostly due to processes related to UV sunlight; e.g., a UV photon from the Sun ionizes an N2 molecule, the emitted electron may be energetic enough so that when it hits another N2 molecule it breaks it apart and excites one of the N fragments to emit a photon at 134 nm). The particle instruments will indirectly study atmospheric escape by measuring ions formed when solar wind protons collide with escaping N2 molecules and steal an electron – the N2+ ions are swept up into the solar wind and are called “pickup ions”. NH will also use the LORRI and MVIC imagers to look for clouds and hazes, or even plumes (as were seen at Triton, a near twin of Pluto).

Source: a conversation I had with Randy Gladstone, who leads the atmospheric studies for the New Horizons mission team.

Posted by: scalbers May 27 2015, 08:59 PM

Very nice Pluto images - hard to believe. In comparing the contrast to other satellites Earth's moon comes to mind.

Posted by: ngunn May 27 2015, 09:20 PM

QUOTE (pitcapuozzo @ May 27 2015, 08:48 PM) *
a conversation I had with Randy Gladstone, who leads the atmospheric studies for the New Horizons mission team.


Randy Gladstone, 'Gladstoner' - any relation? I always had the latter down as a geologist.

Posted by: Phil Stooke May 27 2015, 11:06 PM

Here are the three images side by side. Looks mappable!

Phil



Posted by: Aldebaran May 27 2015, 11:34 PM

It's good to see the surface features of Pluto gradually taking shape.

Hang on. Is it me, or just pareidoglia ?


 

Posted by: Bjorn Jonsson May 27 2015, 11:47 PM

Incredible new images. I mentioned new images in my montage post above but the images I had in mind were images that will be obtained at the end of this month. I was expecting them to look similar to these new images so now I'm getting even more interested in seeing them.

Looking at the three images posted above by Phil it's starting to look as if there might be fairly strong longitudinal contrast variations. There seems to be considerably stronger contrast in the leftmost image but this may be a processing artifact. Anyway I'm now getting seriously interested in knowing which of the features (or which hemisphere) visible in the new images are going to be imaged at really high resolution near closest approach.

Posted by: jgoldader May 28 2015, 02:38 AM

Had to do this...


Posted by: SFJCody May 28 2015, 03:49 AM

Those albedo differences! Seriously exciting.

Posted by: 0101Morpheus May 28 2015, 09:21 AM

QUOTE (Phil Stooke @ May 27 2015, 07:06 PM) *
Here are the three images side by side. Looks mappable!

Phil




Pluto looks less spherical than I expected.

Posted by: Alan Stern May 28 2015, 10:12 AM

QUOTE (jgoldader @ May 28 2015, 03:38 AM) *
Had to do this...



JGoldader-- The faux stamp is awesome! May I use this in social media?

Posted by: TheAnt May 28 2015, 10:29 AM

As for me I appropriated the image of Aldebaran for that purpose. =)

Posted by: Gerald May 28 2015, 10:55 AM

QUOTE (0101Morpheus @ May 28 2015, 11:21 AM) *
Pluto looks less spherical than I expected.

That's (very likely) due to oversampling and high albedo variation.
To discern these effects from real deviations from a spherical shape, we'll need images from closer-up.
Nevertheless Pluto may be heavily cratered; can't wait to see what these features actually are.

Posted by: jgoldader May 28 2015, 11:19 AM

QUOTE (Alan Stern @ May 28 2015, 05:12 AM) *
JGoldader-- The faux stamp is awesome! May I use this in social media?


I would be honored, sir! Glad to give back a little. I got to see Pluto through the UH 2.2m with Dave Tholen back in grad school; now that little dot is becoming a real place, thanks to you and your team. -Jeff

Posted by: Alan Stern May 28 2015, 01:05 PM

QUOTE (jgoldader @ May 28 2015, 12:19 PM) *
I would be honored, sir! Glad to give back a little. I got to see Pluto through the UH 2.2m with Dave Tholen back in grad school; now that little dot is becoming a real place, thanks to you and your team. -Jeff



Thanks Jeff!

Posted by: Phil Stooke May 28 2015, 05:10 PM

Just for the record... I have tried reprojecting the latest three images to make a cylindrical projection map, but I can't get a consistent result. The bright spots don't combine as I would expect. I don't know where the problem is right now. There might be issues with limb brightening and deconvolution that are complicating matters. I hope the science team will put something out so I can see what i am doing wrong.

Phil

Posted by: john_s May 28 2015, 05:35 PM

This is not too surprising- as we noted in the release, we are not confident of the reality of the finest details in these images (deconvolution can do funny things). Fortunately all will be clear very soon!

John

Posted by: alk3997 May 28 2015, 06:00 PM

<deleted> - John provided a better answer...

Posted by: Phil Stooke May 28 2015, 06:00 PM

Thanks, John. So, folks, don't go overboard on the interpretations just yet. Wait - is that a gully?

Phil


Posted by: Jackbauer May 28 2015, 06:05 PM

Left : Hubble (longitude 120°)
Right : NH (longitude 125°)

http://imgbox.com/hlc64miI

Posted by: Paolo May 28 2015, 07:13 PM

is a detailed timeline of the observations at closest approach available somewhere? with times of the occultations and such? I have only found http://pluto.jhuapl.edu/Mission/The-Path-to-Pluto/NH_Obs_Playbook_LORRI-MVIC.pdf for LORRI and MVIC

Posted by: Jackbauer May 28 2015, 07:16 PM

No obstacles found for NH (rings, little moons...)

http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20150528&utm_content=bufferd3bc8&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer

Posted by: djellison May 28 2015, 07:27 PM

QUOTE (Paolo @ May 28 2015, 12:13 PM) *
is a detailed timeline of the observations at closest approach available somewhere? with times of the occultations and such? I have only found http://pluto.jhuapl.edu/Mission/The-Path-to-Pluto/NH_Obs_Playbook_LORRI-MVIC.pdf for LORRI and MVIC


Best I can offer is our New Horizons module for Eyes on the Solar System ( http://eyes.nasa.gov/pluto ) - we have the play by play by means of a predicted simulation.

Posted by: Hungry4info May 28 2015, 07:42 PM

NASA to Hold Media Call to Discuss Surprising Observations of Pluto’s Moons
http://www.nasa.gov/press-release/nasa-to-hold-media-call-to-discuss-surprising-observations-of-pluto-s-moons/

"NASA will host a media teleconference at 1 p.m. EDT on Wednesday, June 3, to discuss the Hubble Space Telescope's surprising observations of how Pluto's moons behave, and how these new discoveries are being used in the planning for the New Horizons Pluto flyby in July."

Posted by: Habukaz May 28 2015, 08:06 PM

So they are misbehaving? Releasing gas, dust? Irregular rotation or orbits?

Posted by: Aldebaran May 28 2015, 08:17 PM

QUOTE (TheAnt @ May 28 2015, 10:29 AM) *
As for me I appropriated the image of Aldebaran for that purpose. =)


Feel free.

Posted by: JRehling May 28 2015, 08:29 PM

The masses of Pluto's minor moons are highly uncertain. If one or more were appreciably more or less massive than expected, it could affect its siblings' motions in an unexpected way. My guess is that HST observations have found that there's more (or much less) perturbation than expected between them due to the mass of one or more of them being outside the expected range.

Additionally, the system is full of near-resonances. This could potentially create complex or chaotic long-term dynamics between them even if the masses were about as expected.

Posted by: Bjorn Jonsson May 28 2015, 09:04 PM

Here are updated versions of the satellite montages I posted two days ago. In addition to new Pluto images I added Europa and Callisto. It seems to me that the resampling of the newly released Pluto images might be different from the resampling in the previous release. I haven't updated the resampling of the satellite images to account for this but still this is an interesting comparison. First a version where all of these bodies look bright:



And then a version where I have attempted to correct for the albedo. This is only approximate but should be fairly fairly realistic:





Posted by: Gerald May 29 2015, 12:04 AM

QUOTE (Phil Stooke @ May 28 2015, 07:10 PM) *
Just for the record... I have tried reprojecting the latest three images to make a cylindrical projection map, but I can't get a consistent result. The bright spots don't combine as I would expect. I don't know where the problem is right now. There might be issues with limb brightening and deconvolution that are complicating matters...

An idea could be trying deconvolution / sr directly on a spherical model, instead of individual 2d stacks. But I'm almost sure, that New Horizons will acquire better images much faster than I could write an according sw. After a first glance at the jpg compression artifacts I knew it would be easier just to wait a few days. Deconvolving compression artifacts ... I've never tried before.

Posted by: Aldebaran May 29 2015, 09:14 AM

I see there are reports of a possible sixth moon, half as bright as Styx on Space News, but I think it could have been a misquote.

From Space News:
http://www.space.com/29513-pluto-moons-rings-check-new-horizons-photos.html

QUOTE
New Horizons spotted all five of Pluto's known moons — Charon, Nix, Hydra, Kerberos and Styx — during this initial search, and scientists determined that the spacecraft could have detected a satellite just half as bright as Styx, which is the faintest of the five.



However, from Space Daily:
QUOTE
The New Horizons hazard detection team, led by John Spencer of the Southwest Research Institute in Boulder, Colorado, determined that small satellites with about half the brightness of Pluto's faintest known moon, Styx, could have been detected at this range.


Ouch! A little different smile.gif I think they are both trying to say that any satellites about half the brightness of Styx ought to be detectable at this range if they existed.

Posted by: Habukaz May 29 2015, 09:32 AM

Just go straight to the http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20150528:

QUOTE
The New Horizons hazard detection team, led by John Spencer of the Southwest Research Institute in Boulder, Colorado, determined that small satellites with about half the brightness of Pluto’s faintest known moon, Styx, could have been detected at this range. Any undiscovered moons outside the orbit of Pluto’s largest and closest moon, Charon, are thus likely smaller than 3-10 miles (5-15 kilometers) in diameter.


They've got an upper limit on the sizes of any undiscovered moons (as well as rings).

Posted by: Floyd May 29 2015, 09:34 AM

Add to the end of the first quote "--if one were there. But it wasn't"

Posted by: TheAnt May 29 2015, 11:00 AM

Yes even though english isn't my first language, even I jumped at how they had phrased it there. No reason to add more fuel to the fire where 'some' do their best misinterpreting every result or image.

Posted by: Gerald May 29 2015, 03:05 PM

The preceeding paragraph is quite clear:

QUOTE
But the first hazard-search images ... revealed no new moons, rings or anything else to be concerned about,

without use of the ambiguous meaning of the word "could".

By stacking 2x48 images I would have been surprised not to find even a tiny hint to a ring, if it would have been obvious, even with the jpegs.
But it's something else to confirm a moon than to find a new one, particularly if it's outside the orbital plane of Charon, or if its orbit is very eccentric.

Posted by: MizarKey May 30 2015, 03:52 AM

I think this is the most excited I've been in quite some time. Pluto promises exciting new discoveries. Close encounter is a week or so after my birthday, What a gift!

Posted by: Paolo May 30 2015, 06:53 AM

QUOTE (MizarKey @ May 30 2015, 05:52 AM) *
I think this is the most excited I've been in quite some time.


same here. I planned to take some vacation and disconnect from the internet, cellphones and wifi during July, but then I realized I've been waiting to see Pluto ever since I heard of the Pluto Fast Flyby proposal almost 25 years ago and I changed of plans.
I didn't do it neither for Curiosity landing (I was somewhere in the Gobi desert at the time) nor for Rosetta's arrival (I was somewhere in central Asia)

Posted by: Gerald Jun 1 2015, 05:34 PM

(This post is still about images before 2015-05-15.)

http://pluto.jhuapl.edu/soc/Pluto-Encounter/data/pluto/level2/lor/jpeg/029379/lor_0293791423_0x630_sci_13.jpgs of the LORRI map series have been provided in sets of four (quadruples).
In contrast to the 4x4-binned images, those aren't aligned (fortunately just translated), and may show CRs or stars of variable brightness. Here a version with cross hairs indicating the spots above some brightenss trigger level, animated over one of these quadruples:
http://imgur.com/NJp1UCc
These fluctuations, together with lack of much background features, make automated and sufficiently fast registering a little tricky, but still well-feasible with some effort:
http://imgur.com/ZKyzpFp
(You may notice no change at all at first glance; that's due to accurate registering.)
This registering is the basis for any further useful processing...
(The medium-term goal is accurate determination of the Pluto and Charon orbits and positions for later surface mapping attempts exploiting mutual tidal locking. This needs some intermediate steps as preparation.)

Posted by: wildespace Jun 2 2015, 09:32 AM

Too funny not to share it here: http://xkcd.com/1532/

laugh.gif

Posted by: Habukaz Jun 2 2015, 08:33 PM

A big batch of new http://pluto.jhuapl.edu/soc/Pluto-Encounter/index.php?page=1 from the 28th to the 30th of May have been released. Pluto is starting to look very big, but the PSF is still dominating (I guess), so there's probably not much to be gained by staring long and hard at them.

Posted by: Phil Stooke Jun 2 2015, 11:24 PM

From those new images: this is a composite of four frames, enlarged 400%. I can't do fancy-schmancy deconvolution so I'm just playing with Photoshop. Some detail is visible on Pluto even without deconvolution, but a bright limbward rim on the prominent dark spot is absolutely certainly an artifact!

Phil


Posted by: Bjorn Jonsson Jun 3 2015, 12:12 AM

This reveals a relatively dark, narrow feature oriented roughly between the 4 o'clock and 10 o'clock positions - it may have been visible in the earlier set of images as well (I haven't checked the subspacecraft longitude).

What I think is really interesting now is whether deconvolution would start revealing details on Charon. It's going to be very interesting to see what the next set of deconvolved images released by the NH team look like.

Posted by: 0101Morpheus Jun 3 2015, 12:41 AM

Trying to understand Pluto without Charon is like trying to put a puzzle together with only half the pieces. Or with a quarter of the pieces, in accordance with the square-cube law.

Posted by: Gerald Jun 3 2015, 12:50 AM

That's my cleaned and stacked, cropped, 4x-magnified versions of the 2015-05-28, 2015-05-29, and 2015-05-30 full-frame 1x1-binned quadruples:


I didn't apply any enhancement or rotational adjustment, just cleaning and stacking by averaging the three most similar pixel values of each of the four registered images within each set.

Posted by: ZLD Jun 3 2015, 02:14 AM

QUOTE (Phil Stooke @ Jun 2 2015, 05:24 PM) *
Some detail is visible on Pluto even without deconvolution,


Probably over did it but I think Pluto is still a bit too far away to make deconvolution all that useful.

Posted by: Phil Stooke Jun 3 2015, 03:09 AM

I always thought Pluto was some sort of weird hound, but it looks more like a Pug in that view!

Phil


Posted by: Gerald Jun 3 2015, 12:04 PM

This image is obtained by averaging 4-fold magnified and registered versions, both together in a one-step transformation (by bilinear interpolation), of the four 2015-05-30 full-frame 1x1 binned LORRI images. After linear reduction of brightness, excessive sharpening, followed by another 4-fold magnification for better visibility:



This is a look at the radius-2 hipass portion of the (4x4-fold supersampled) average image, again another 4-fold magnification for better visibility, and a 16-fold brightness-stretch:

From the latter image I'd say, the dark region at the right is well above jpg artifact level, same for the more or less diagonal central darkish area. There may be some additional structuring, but it competes with artifacts.
For Charon I don't see much more than the PSF and artifacts.

For completeness, here a 4-frame animated gif, made of the registered 4-fold magnified (bilinear) and cropped images, before averaging and sharpening:

Posted by: Gerald Jun 3 2015, 04:14 PM

The new LORRI 4x4-binned images seem to consist of at least two series, one with exposure time a little below 3s, summarized as OpNav Campaign 4,
and "footprint" images with exposure a little below 10s, like previous 4x4-binned images.

Starting with OpNav Campaign 4:
The images are now taken in sets of 6, in contrast to sets of 5 as in OpNav Campaign 3.
I've still to adjust to the additional 6th image, so here a preliminary overview with only 5 of each image series, plus the stacked image:
http://imgur.com/qm0X7v0
Thus far there are 4 such sets available.
http://imgur.com/a/h6ykF#0.

Two moons (Nix/Hydra) are well-perceivable, Styx and Kerberos not (yet) obvious.

Posted by: Paolo Jun 3 2015, 05:06 PM

meanwhile, http://hubblesite.org/newscenter/archive/releases/2015/24/
there should be a Nature paper out soon, but I can't find it yet

Posted by: Explorer1 Jun 3 2015, 05:08 PM

June 4th issue according to this article: http://www.nature.com/news/pluto-s-moons-move-in-synchrony-1.17681#b1

Resonances too.

Posted by: Paolo Jun 3 2015, 05:10 PM

paper is here: http://www.nature.com/nature/journal/v522/n7554/full/nature14469.html

Posted by: SFJCody Jun 3 2015, 05:35 PM

Press release renderings of the moons are lovely, but they must surely have some of the shortest usable lifespans of any such images ever made. Reality is fast approaching... laugh.gif

Posted by: ChrisC Jun 3 2015, 05:47 PM

QUOTE (Hungry4info @ May 28 2015, 02:42 PM) *
NASA to Hold Media Call to Discuss Surprising Observations of Pluto’s Moons
http://www.nasa.gov/press-release/nasa-to-hold-media-call-to-discuss-surprising-observations-of-pluto-s-moons/
NASA will host a media teleconference at 1 p.m. EDT on Wednesday, June 3, to discuss the Hubble Space Telescope's surprising observations of how Pluto's moons behave, and how these new discoveries are being used in the planning for the New Horizons Pluto flyby in July.
Audio of the teleconference will be streamed live at: http://www.nasa.gov/newsaudio


Was anybody able to gets the NASA newsaudio stream to work? All I ever got was the page with a blank/black embedded window, no playback.

Now I have to hope that someone captured it ...

Posted by: Gerald Jun 3 2015, 09:04 PM

Yeah, time is running short with publishing discoveries near Pluto, before New Horizons will overtake in the next weeks.
Besides this, any a-priori knowledge would be useful for hazard assessment.

...Here an overview of eight series of "footprint" images, all taken on 2015-05-30 within less than an hour:
http://imgur.com/8dgxlsS
(using 5 of 6 images of each series due to restrictions of my software, but this should yield useful results already)

All these images should be "stackable" to one image with reasonable "motion blur".
I'll see, whether I can convince my computer to do so.

Posted by: Gladstoner Jun 3 2015, 09:09 PM

Was this the subject of today's press release?

http://www.wired.com/2015/06/odd-orbits-deepen-plutos-mystery/

Posted by: Gerald Jun 3 2015, 10:11 PM

My computer has been more successful with registering and stacking the images than me with finding a recorded version of the audionews in the same time.

So http://imgur.com/a/Moh03#0.

And the median and mean:
http://imgur.com/U4BZkBo http://imgur.com/p9ne9Rg

Posted by: Gerald Jun 3 2015, 11:04 PM

Blink between "Search for sources of hazmat" and 2015-05-30 "footprint", roughly registered to stars:


I've marked the two obvious moons.

Posted by: stevesliva Jun 3 2015, 11:25 PM

QUOTE (Gladstoner @ Jun 3 2015, 05:09 PM) *
Was this the subject of today's press release?

http://www.wired.com/2015/06/odd-orbits-deepen-plutos-mystery/


There was a announcement of the Hubble findings.

I'm curious if it affects dust location predictions.

Posted by: john_s Jun 4 2015, 01:48 PM

QUOTE (Gerald @ Jun 3 2015, 05:04 PM) *
Blink between "Search for sources of hazmat" and 2015-05-30 "footprint", roughly registered to stars:
I've marked the two obvious moons.


Yup- that's Nix and Hydra! Their distance from Pluto and Charon is getting quite large in the latest set.

John

Posted by: alk3997 Jun 4 2015, 02:58 PM

QUOTE (john_s @ Jun 4 2015, 07:48 AM) *
Yup- that's Nix and Hydra! Their distance from Pluto and Charon is getting quite large in the latest set.

John


John, I'm curious...How close will NH need to be before changes in Nix or Hydra's brightness can be detected over an orbit? I guess what I'm really asking is how close does the spacecraft need to be before hints of the satellites' chaotic rotations can be detected?

Andy

Posted by: epoca Jun 4 2015, 03:11 PM

QUOTE (Gerald @ Jun 3 2015, 11:04 PM) *
Blink between "Search for sources of hazmat" and 2015-05-30 "footprint", roughly registered to stars:


I've marked the two obvious moons.


Just wondering, how do you start from something like this, with very few dots,

http://pluto.jhuapl.edu/soc/Pluto-Encounter/data/pluto/level2/lor/jpeg/029527/lor_0295273209_0x633_sci_3.jpg

and end with something like one of your animation's frames, which have a lot more? Thanks and great work as always!

Posted by: Gerald Jun 4 2015, 03:16 PM

A difference image, stretched a little more than 16x:



first regarding alk3997:
Determining the brightness fluctuations from this distance is mainly a matter of statistics. So besides the distance it depends on the number of images taken, and to some degree on time intervals between images with respect to the rotation or oscillation period of the moons.
And introductory question would be:
- What's the relative amplitude and frequency of the brightness oscillations of the moons?

From the S/N of the images one could then derive the number of the samples needed for a given confidence level.
(Just my preliminary answer.)

Posted by: Gerald Jun 4 2015, 03:36 PM

QUOTE (epoca @ Jun 4 2015, 05:11 PM) *
Just wondering, how do you start from something like this, with very few dots,
and end with something like one of your animation's frames, which have a lot more? Thanks and great work as always!

Thanks!
I've explained part of it in http://www.unmannedspaceflight.com/index.php?s=&showtopic=7970&view=findpost&p=220932.
In this case there are eight sets of sets of six images.
First I've summed up all images within each set separately (or five of the six images of the set), with some bias, to get a background near black, the raw images within the set are already well-registered; the sum at each pixel position skips the summand with the largest deviation to get the image cleaned from point noise and CRs. Then the resulting eight summed images are registered to subpixel accuracy (up to about 0.004 pixels, with a lot of number crunching), magnified by bilinear interpolation, and averaged, summed or median-filtered to extract as much of the fainter information as possible from the set of 48 images into one image.

Then repeat it with another set of e.g. 48 images, taken at a significantly different time, e.g. another day. The result are two "reduced" images, ready for the blink gif, or for differencing.

Posted by: john_s Jun 4 2015, 03:43 PM

QUOTE (alk3997 @ Jun 4 2015, 08:58 AM) *
John, I'm curious...How close will NH need to be before changes in Nix or Hydra's brightness can be detected over an orbit? I guess what I'm really asking is how close does the spacecraft need to be before hints of the satellites' chaotic rotations can be detected?

Andy


You don't need to be very close for lightcurve work- we've been tracking Nix and Hydra brightnesses for a couple of months now. The data get better as we get closer, though.

John

Posted by: alk3997 Jun 4 2015, 03:53 PM

QUOTE (john_s @ Jun 4 2015, 10:43 AM) *
You don't need to be very close for lightcurve work- we've been tracking Nix and Hydra brightnesses for a couple of months now. The data get better as we get closer, though.

John


John and Gerald, Thanks!

Andy

Posted by: katodomo Jun 4 2015, 09:25 PM

From the press releases i'm not entirely sure: Has the albedo estimate for Kerberos been adjusted downwards? The "5% of Nix and Hydra" in the Wired article linked above would suggest so - dramatically. ("as black as coal" isn't a very exact estimate either wink.gif )

If the albedo estimate has been adjusted downwards - is there a new size estimate?

Posted by: Hungry4info Jun 4 2015, 11:25 PM

Yes. See the actual paper.
http://hubblesite.org/pubinfo/pdf/2015/24/pdf.pdf

Posted by: Gerald Jun 6 2015, 01:59 PM

A first overview of cleaned and stacked 4x4 binned LORRI images with a little less than 3 seconds exposure time, in the OpNav Campaign 4 style, but "untitled", taken from 2015-05-31 to 2015-06-02:


Some of the images may be motion-blurred a bit.

... there have been released other images as well, but "con algo hay que empezar".

Posted by: Gerald Jun 6 2015, 03:10 PM

Reduction to 3-fold magnifiction and gif animation of the registerd versions of the above series leads to significant loss of information, but Nix and Hydra can nevertheless be perceived:
http://imgur.com/9e8Q7j5
http://imgur.com/a/ll769#0.

Posted by: Habukaz Jun 6 2015, 03:16 PM

Non-binned images between 29 May and 5 June, Pluto-centric, no extra processing:



we really need a new official deconvoluted release! wink.gif

Posted by: Paolo Jun 6 2015, 03:25 PM

impressive, features on Pluto are now clearly visible even with modest processing (just tweaked the contrast and zoomed 4x without interpolation)

 

Posted by: Gerald Jun 6 2015, 03:30 PM

... For completeness, the differenced "untitled" 4x4 binned sequence, showing at least Nix and Hydra:



Posted by: Gerald Jun 6 2015, 04:02 PM

QUOTE (Paolo @ Jun 6 2015, 05:25 PM) *
impressive, features on Pluto are now clearly visible even with modest processing (just tweaked the contrast and zoomed 4x without interpolation)

The three latest 1x1-binned frames (taken within 30 seconds, after system time 0295786798) cropped, heavily sharpened, and animated:

Features on Pluto look reproducible, enhanced Charon features look like random noise/artifacts. But I'm almost sure, that at least with lossless images we may see first Charon features soon.

Posted by: Habukaz Jun 6 2015, 04:22 PM

^ Those aren't even the latest images any more, we just got today's images. wink.gif



Pluto looks like a wannabe Iapetus from this angle (cropped, unprocessed).

Posted by: epoca Jun 6 2015, 05:05 PM

Thanks for sharing!

Posted by: pitcapuozzo Jun 6 2015, 05:07 PM

In case anyone's interested, this is a plot of New Horizon's trajectory through the Pluto system. I produced it with a couple of New Horizons mission team members, so all the data you find here is 100% reliable/verified. The visual representation obviously isn't realistic, as I had to enlarge each body to make it visible and tweak a few other things, however it shold be pretty good unless you actually had to drive through the Pluto system.


Posted by: Gerald Jun 6 2015, 07:35 PM

"In case anyone's interested..." I'm sure everyone here is interested, and wants to be prepared.

QUOTE (Habukaz @ Jun 6 2015, 06:22 PM) *
^ Those aren't even the latest images any more, we just got today's images. wink.gif

Those new "footprints" of 2015-06-05 look promising already,

although the sets I've used here haven't yet been complete:
http://imgur.com/CzCgd9l http://imgur.com/UMYeSaA
The two series have been taken on the same day, the second one about 14 hours later than the first one.

Posted by: Phil Stooke Jun 6 2015, 08:18 PM

This is a merged set of Gerald's three frames from his animation. Getting closer!

Phil


Posted by: Paolo Jun 7 2015, 06:06 AM

QUOTE (pitcapuozzo @ Jun 6 2015, 07:07 PM) *
In case anyone's interested, this is a plot of New Horizon's trajectory through the Pluto system.


I have a question: what are the occultation times? occultation beginning, occultation end or what else?
it would be great if you could give the time of both the beginning and end of the occultation

Posted by: pitcapuozzo Jun 7 2015, 10:00 AM

QUOTE (Paolo @ Jun 7 2015, 08:06 AM) *
I have a question: what are the occultation times? occultation beginning, occultation end or what else?
it would be great if you could give the time of both the beginning and end of the occultation


Ciao, I believe that the times the New Horizons team gave me for the occultations are the times when the sun sets over Pluto and Charon. For example, from what I understood, solar ingress at Pluto is from 12:16 to 12:49, and the sun is expected to set at about 12:51:25, which is the time I reported. I'm not 100% sure so I might ask, however what I said should be at least vaguely correct, maybe the solar ingress times have changed a bit.

Also, just as a side node, New Horizons will also observe a third "solar" occultation starting about 4 hours after closest apporach, when Pluto will obscure a bright UV star.

Posted by: Aldebaran Jun 7 2015, 11:45 AM

QUOTE (pitcapuozzo @ Jun 6 2015, 06:07 PM) *
In case anyone's interested, this is a plot of New Horizon's trajectory through the Pluto system. I produced it with a couple of New Horizons mission team members, so all the data you find here is 100% reliable/verified.


Meraviglioso. This is very impressive and useful.

Posted by: surbiton Jun 7 2015, 01:05 PM

QUOTE (pitcapuozzo @ Jun 7 2015, 10:00 AM) *
Ciao, I believe that the times the New Horizons team gave me for the occultations are the times when the sun sets over Pluto and Charon. For example, from what I understood, solar ingress at Pluto is from 12:16 to 12:49, and the sun is expected to set at about 12:51:25, which is the time I reported. I'm not 100% sure so I might ask, however what I said should be at least vaguely correct, maybe the solar ingress times have changed a bit.

Also, just as a side node, New Horizons will also observe a third "solar" occultation starting about 4 hours after closest apporach, when Pluto will obscure a bright UV star.


Does that mean that at closest approach Pluto will be bathed with the evening sun or just from the position where NH will be ?

Since, NH will be coming from the Sunward side, initially it will be see Pluto in sunlight [ close to noon ]. As it passes Pluto, it will see
Pluto as a crescent. How many cameras are on board ? Can NH take pictures of Charon while also taking Pluto's ?

[ADMIN: Please help us avoid forum redundancy and clutter. These are the kinds of questions that can EASILY be answered with a Google search or by checking the NH web site.]

Posted by: scalbers Jun 7 2015, 02:14 PM

Indeed NH is on the sunward side right now with the images we're receiving and will continue to be on this side up until near closest approach. It might be interesting to see an ephemeris of Pluto as seen from NH including phase angle and sub-spacecraft latitude and longitude, if anyone has one handy?

Posted by: pitcapuozzo Jun 7 2015, 02:49 PM

QUOTE (Aldebaran @ Jun 7 2015, 01:45 PM) *
Meraviglioso. This is very impressive and useful.


Thanks!

QUOTE (surbiton @ Jun 7 2015, 03:05 PM) *
How many cameras are on board ? Can NH take pictures of Charon while also taking Pluto's ?


The main camera is Ralph, which is tasked with taking the very high res maps. Ralph consists of two components, MVIC (3 panchromatic and 4 color imagers) and LEISA (an infrared spectrometer). MVIC operates over the bandpass from 0.4 to 0.95 microns. Ralph has 7 CCDs, plus 1 infrared array detector.

The camera being used right now to take almost 100% of the images returned so far is LORRI, a panchromatic high-magnification imager, consisting of a telescope with an 8.2-inch (20.8-centimeter) aperture that focuses visible light onto a CCD.

If I recall correctly, New Horizons has enough power to gather data with 5 instruments simultaneously. If you're interested in seeing the sequence of the scientific operations, I suggest you take a look at NASA's Eyes on the Solar System. Or, if you're just interested in the observations, then this is a great PDF:

http://pluto.jhuapl.edu/Mission/The-Path-to-Pluto/NH_Obs_Playbook_LORRI-MVIC.pdf

Posted by: surbiton Jun 7 2015, 08:15 PM

QUOTE (pitcapuozzo @ Jun 7 2015, 02:49 PM) *
If I recall correctly, New Horizons has enough power to gather data with 5 instruments simultaneously. If you're interested in seeing the sequence of the scientific operations, I suggest you take a look at NASA's Eyes on the Solar System. Or, if you're just interested in the observations, then this is a great PDF:

http://pluto.jhuapl.edu/Mission/The-Path-to-Pluto/NH_Obs_Playbook_LORRI-MVIC.pdf


Thanks.

Posted by: surbiton Jun 7 2015, 08:24 PM

This is the most excited I have been about a space mission - probably because of the time it has taken.
But most certainly, this will be the only time in my lifetime [ and I am very optimistic person ]
we will have been that close to Pluto.

I wish we could have orbited but I appreciate NH will be travelling far too quickly for that.

By the way, did we know where Charon would be [ in relation to Pluto ] in 2006 ?


Posted by: lollipop Jun 7 2015, 09:18 PM

OK, so you are planning the encounter trajectory. You must maximise the chances of passing through intact so rings are an issue. And you want the Earth and Sun occultations for Pluto and Charon for radio/atmospheric science. And there is no point getting too close because everything will be a blur. And blowing through at 50, 000km/h you can't afford to spend too much time rotating.
All in all you want the moons all on one side of Pluto, and take NH by on the other side at a sensible distance.

Is Pluto's gravity strong enough to make the occultations work whichever side you go, or is it built in to the heliocentric trajectory?

Posted by: ZLD Jun 7 2015, 09:33 PM




So this bit confused me. I've never come across this particular graphic with an error zone. Does it infer the remote possibility that we may capture nearly nothing should Pluto be in the upper right most portion? I'm not the least bit worried but that zone seems rather large.

Posted by: lollipop Jun 7 2015, 09:41 PM

Giving it more thought, aided by a beer, it is obvious that NH must pass to the East, "in front of" Pluto, and have Pluto's orbital motion (3-4 km/s) bring it into line behind NH. And the spacecraft will have to move in the Pluto-Charon-Earth/Sun plane to get the occultations.

Posted by: ChrisC Jun 8 2015, 01:17 AM

QUOTE (ChrisC @ Jun 3 2015, 01:47 PM) *
Was anybody able to gets the NASA newsaudio stream to work? All I ever got was the page with a blank/black embedded window, no playback.
Now I have to hope that someone captured it ...


I did end up finding a recording of the June 3rd press conference, so I thought I'd contribute by sharing.

First, here is a Youtube recording of the telecon. It has the telecon audio, and the slides as video, but the motion video is not playing. In other words, when they offered an animation, all you see here is the first frame:

https://www.youtube.com/watch?v=AKPMYkgi-tY

(side note: if anyone here has a Youtube account, please thank that user, Matthew Travis, for recording and posting it!)

Second, here's the briefing materials, with working animations:

http://www.nasa.gov/content/goddard/briefing-materials-observations-of-pluto-s-moons

So, listen to the Youtube video's audio, while looking at the briefing materials.

Finally, for completeness ...

QUOTE (Hungry4info @ Jun 4 2015, 07:25 PM) *
Yes. See the actual paper. http://hubblesite.org/pubinfo/pdf/2015/24/pdf.pdf

Posted by: elakdawalla Jun 8 2015, 05:56 PM

QUOTE (ZLD @ Jun 7 2015, 01:33 PM) *



So this bit confused me. I've never come across this particular graphic with an error zone. Does it infer the remote possibility that we may capture nearly nothing should Pluto be in the upper right most portion? I'm not the least bit worried but that zone seems rather large.

The error ellipse has to do with uncertainty in Pluto's orbital position -- because we haven't tracked it over a full orbit, the uncertainty in its path is more than we're used to for planets, moons, and asteroids. Optical navigation images being taken now will help to reduce the uncertainty, and they'll be able to update parameters close to encounter to accommodate better positional predictions, but they've had to plan the whole encounter with the best orbital predictions we have, and yes, that error zone captures the level of uncertainty. Like any error ellipse, though, Pluto is more likely to be in the middle of the zone than at the edge.

Posted by: JRehling Jun 8 2015, 06:14 PM

The best images so far keep reminding me of what Titan looked like in pre-Cassini imagery, although there's not much chance that the dark areas on Pluto have the same origin as on Titan (e.g., sand dunes).

This is starting to get good.

Some of us have lived through the first spacecraft reconnaissance of Venus, the Galileans, etc. All of us for Titan, some of us for Mars. But this is it. This is almost certainly the last time that a world of this size will be visited for the first time by spacecraft in our lifetimes, barring the unlikely event of a blazing-fast trajectory to Eris.

Savor the moment. It won't come again.

Posted by: Phil Stooke Jun 8 2015, 08:52 PM

It is getting good!

But I expect some of us can remember when the far side of the Moon was the frontier of exploration.


Phil


Posted by: Gerald Jun 9 2015, 12:39 AM

An update of the 2015-06-05 "footprint" images, with 6x9, 8x9, and 8x9 images, total exposure times a little less than 9, 12, and 12 minutes respectively:
http://imgur.com/Mw1bvzW http://imgur.com/9fNE1am http://imgur.com/Zt0gJgb

Animation of three stacked images:
http://imgur.com/0GPDrnD
Preliminary differences 4-fold stretched, animated:
http://imgur.com/VaQwHss
There are probably ways to improve the latter numerically, since I've been storing the stacked files with 8-bit channels.

Posted by: MahFL Jun 9 2015, 11:39 AM

QUOTE (ZLD @ Jun 7 2015, 10:33 PM) *



So this bit confused me. I've never come across this particular graphic with an error zone. Does it infer the remote possibility that we may capture nearly nothing should Pluto be in the upper right most portion? I'm not the least bit worried but that zone seems rather large.


No, it means the right edge of Pluto could be on the right of the ellipse, so you'd still get the data, the downside is the extra images take up space on the data recorder, but it's a trade off to make sure you get the data needed. Also it accommodates any slight errors in pointing by the spacecraft, but the spacecraft pointing has as far as I know been excellent, as you'd expect with such a good team.

Posted by: MahFL Jun 9 2015, 11:43 AM

QUOTE (elakdawalla @ Jun 8 2015, 06:56 PM) *
.... and they'll be able to update parameters close to encounter to accommodate better positional predictions...


My impression was the flyby sequence was loaded way back in 2009, and won't be changed, except to fill in gaps that were deliberately left to accommodate imaging new moons.

Posted by: Alan Stern Jun 9 2015, 11:54 AM

QUOTE (MahFL @ Jun 9 2015, 11:43 AM) *
My impression was the flyby sequence was loaded way back in 2009, and won't be changed, except to fill in gaps that were deliberately left to accommodate imaging new moons.


The flyby sequence was finalized after the 2012 spacecraft rehearsal. No additions are allowed. The only changes are to fill in blanks like DSN schedules we did not know in 2012. Better is the Enemy of Good Enough, we prefer 80% of something to 100% of nothing-- we're not taking risks just to do a little better.

Posted by: jgoldader Jun 9 2015, 02:14 PM

QUOTE (Alan Stern @ Jun 9 2015, 06:54 AM) *
The flyby sequence was finalized after the 2012 spacecraft rehearsal. No additions are allowed. The only changes are to fill in blanks like DSN schedules we did not know in 2012. Better is the Enemy of Good Enough, we prefer 80% of something to 100% of nothing-- we're not taking risks just to do a little better.


Alan, is there a doc you can point to, or much you can say (without spending too much of your very valuable time!) about how fault protection is going to be handled during the period around close approach? I'd assume there is some sort of inhibition against entering safe mode for most possible faults, but maybe I'm wrong on that. Thanks!

Posted by: Habukaz Jun 9 2015, 02:18 PM

Pluto and Charon in raw images from 5-8 June:







Here's an enlarged version for Charon for 5-7 June:



I guess we might be seeing hints of surface variation on Charon in the raw images (edit: after posting this, I realised comparing frames taken seconds/similar between them would be a good way to check the noise levels..).

Posted by: Phil Stooke Jun 9 2015, 03:48 PM

Very good! I split the Pluto gif into its four frames and processed them to bring out more detail. Not a real deconvolution, but playing with histograms in multiple layers.

Phil


Posted by: ZLD Jun 9 2015, 06:06 PM

So I applied some light LR-deconvolution to your processed frames Phil.



NH is approaching Pluto with one of the poles somewhat facing us correct? Maybe I'm too excited and hopeful here, but those look and behave like atmospheric structures, like clouds.

Edit: Also before this blows up, grain of salt here. Deconvolution can sometimes add strange artifacts. We are still too far away for it to provide entirely reliable information.

Edit 2: Went back and made a few modification to settings to lighten up the impact of the process. The right animation used maximum entropy followed by a Lucy Richardson process.


Click to animate

Posted by: Alan Stern Jun 9 2015, 06:20 PM

QUOTE (jgoldader @ Jun 9 2015, 02:14 PM) *
Alan, is there a doc you can point to, or much you can say (without spending too much of your very valuable time!) about how fault protection is going to be handled during the period around close approach? I'd assume there is some sort of inhibition against entering safe mode for most possible faults, but maybe I'm wrong on that. Thanks!



Correct. Encounter Mode (P-7 to P=2) locks out safe hold. See papers on NH "Autonomy" system in AIAA and IEEE proceedings by Bauer et al.

Posted by: Julius Jun 9 2015, 07:28 PM

My wild guess regarding the dark areas within the bright areas..I believe we could be seeing first signs of sublimation of ice!

Posted by: Bjorn Jonsson Jun 9 2015, 09:45 PM

Here are two versions of an image that is a stack of four images obtained 15 seconds apart on June 6 at a range of 45.8 million km. Here they have been enlarged by a factor of four.



I used these images:

lor_0295859743_0x630_sci_1.jpg
lor_0295859728_0x630_sci_3.jpg
lor_0295859713_0x630_sci_3.jpg
lor_0295859698_0x630_sci_3.jpg

The left version is the stack without any processing so it should show correct relative brightness. The right version has been sharpened using RegiStax. The sharpened version reveals a diagonal dark band on Pluto - it's now absolutely certain that this is a real feature. In contrast, the apparently brighter terrain at the right limb is almost certainly a processing artifact. Charon may be starting to show large scale markings, i.e. possibly very slightly darker terrain in its upper left 'quadrant'. But this could easily be an image processing artifact.

The left version can be used to make crude brightness estimates. Using 1 for Pluto's brightest terrain, Charon's surface is ~0.5, the brightness of Pluto's dark 'band' is ~0.9 (not very accurate) and the darkest terrain is ~0.25 to 0.3. The dark terrain is rather close to the limb so 0.25-0.3 isn't very accurate but nevertheless this seems to indicate that even though Pluto has large albedo variations, the contrast is probably significantly less than on Iapetus.

It wouldn't surprise me if small dark spots started appearing within the bright terrain at much higher resolution and/or small bright spots started appearing within the dark terrain.

QUOTE (Julius @ Jun 9 2015, 07:28 PM) *
My wild guess regarding the dark areas within the bright areas..I believe we could be seeing first signs of sublimation of ice!

This seems very plausible. Also one crazy idea is that some of the dark terrain could be associated with activity of some kind, maybe like Triton's dark geysers, but it's rather early to start speculation about that. But things are starting to get really exciting now that the images are clearly better than the best HST images.

Posted by: Gerald Jun 10 2015, 01:30 AM

This is a stacked and heavily sharpened (before and after stacking) version of three 2015-06-09 Pluto/Charon images:


I'm very skeptical about this strong sharpening. So we may see anything from processing artifacts to a giant storm on Pluto. Charon is going to show reproducible features.

Edit: Color-encoded brightness of stacked image without sharpening, to offer an alternative view:

There is a clear asymmetry of the brightness, but interpretation is partly suggested by processing.

Posted by: elakdawalla Jun 10 2015, 05:10 AM

The intense ring around Pluto looks like over-sharpening to me. There is information in these images, but so little that it's easy to destroy with overzealous processing.

Posted by: Gerald Jun 10 2015, 10:22 AM

This is a "faked" image as comparison, starting with no relevant features, and similar sharpening:


It's rather rotational symmetric. So deviation from the rotational symmetry in the processed original images hint towards real features. But besides the optical PSF there is an additional risk of enhancing jpg artifacts, since the processed Pluto image is a composite of only three jpg-compressed images.

Posted by: ZLD Jun 10 2015, 02:01 PM

Heres a processed version of 'lor_0296134018_0x630_sci_1' from yesterday.



Max entropy deconvolution and some histogram functions.

Posted by: Phil Stooke Jun 10 2015, 02:51 PM

My version of the June 9th images, the three LORRI images merged. A bright right edge on Pluto itself is an artifact of my appallingly ad-hoc processing method.

Phil


Posted by: paraisosdelsistemasolar Jun 10 2015, 07:00 PM

New images taken today!



Edit: Sorry, I forgot to add the original source: http://pluto.jhuapl.edu/soc/Pluto-Encounter/view_obs.php?image=data/pluto/level2/lor/jpeg/029620/lor_0296205838_0x630_sci_1.jpg&utc_time=2015-06-10%3Cbr%3E01:32:00%20UTC&description=OpNav+Campaign+4%2C+LORRI+1X1&target=PLUTO&range=41.0M%20km&exposure=100%20msec

Posted by: Bjorn Jonsson Jun 10 2015, 08:27 PM

It's very interesting to see the image together with the diagram showing the image orientation. It's starting to look as if Pluto has a bright polar cap, a somewhat darker collar around the bright polar areas and then brighter terrain in the equatorial areas - not as bright as the polar terrain though.

Close inspection of the original, unprocessed image seems to imply that the poleward (northern) edge of the collar might be more subtle and less sharply defined than the southern edge (the edge closer to the equator).

Edit: Of course other images show that *if* there is a darker collar around the bright polar terrain its extent to the south is probably nonuniform and varies with longitude.


Posted by: paraisosdelsistemasolar Jun 10 2015, 09:17 PM

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.


Posted by: jasedm Jun 10 2015, 09:52 PM

QUOTE (Bjorn Jonsson @ Jun 10 2015, 09:27 PM) *
It's starting to look as if Pluto has a bright polar cap, a somewhat darker collar around the bright polar areas and then brighter terrain in the equatorial areas - not as bright as the polar terrain though.


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?

Posted by: Gladstoner Jun 10 2015, 10:27 PM

QUOTE (jasedm @ Jun 10 2015, 03:52 PM) *
I wonder if we'll see any 'canteloupe' terrain?


Or geyser plume trails?

Posted by: JRehling Jun 10 2015, 11:15 PM

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.

Posted by: Bjorn Jonsson Jun 10 2015, 11:34 PM

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.

QUOTE (JRehling @ Jun 10 2015, 11:15 PM) *
Pluto and Triton may be very similar in terms of size and bulk constituency, but they are very different in terms of seasons

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.

Posted by: pioneer Jun 11 2015, 12:51 AM

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

Posted by: Phil Stooke Jun 11 2015, 01:37 AM

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


Posted by: TheAnt Jun 11 2015, 03:29 AM

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.

Posted by: Alan Stern Jun 11 2015, 04:19 AM

QUOTE (TheAnt @ Jun 11 2015, 03:29 AM) *
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.

Posted by: Julius Jun 11 2015, 11:35 AM

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!

Posted by: TheAnt Jun 11 2015, 01:53 PM

QUOTE (Alan Stern @ Jun 11 2015, 06:19 AM) *
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.


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. =)

Posted by: ZLD Jun 11 2015, 02:00 PM

Latest from yesterday.



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

Posted by: jgoldader Jun 11 2015, 03:49 PM

QUOTE (ZLD @ Jun 11 2015, 10:00 AM) *
Latest from yesterday.



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

Posted by: SFJCody Jun 11 2015, 04:13 PM

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. laugh.gif

Posted by: scalbers Jun 11 2015, 05:07 PM

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).

Posted by: Habukaz Jun 11 2015, 07:15 PM

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.




Posted by: Habukaz Jun 11 2015, 09:17 PM

http://www.nasa.gov/feature/different-faces-of-pluto-emerging-in-new-images-from-new-horizons No word on Charon.

Down-scaled 4-frame version:



Posted by: Explorer1 Jun 11 2015, 10:06 PM

Media schedule is out now; quite busy!

http://www.nasa.gov/press-release/nasa-announces-television-coverage-media-activities-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!

Posted by: Phil Stooke Jun 11 2015, 10:17 PM

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

Phil


Posted by: ZLD Jun 11 2015, 11:00 PM

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. unsure.gif

Posted by: Gerald Jun 11 2015, 11:17 PM

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.

Posted by: 4throck Jun 11 2015, 11:22 PM

QUOTE (Phil Stooke @ Jun 11 2015, 11:17 PM) *
Here is a different processing of the deconvolved frames...


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

Posted by: Phil Stooke Jun 12 2015, 12:11 AM

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

Phil



Posted by: jgoldader Jun 12 2015, 12:52 AM

QUOTE (Phil Stooke @ Jun 11 2015, 08:11 PM) *
These are the frames taken from the new video, giving a full rotation.

Phil




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

Posted by: Aldebaran Jun 12 2015, 01:10 AM

QUOTE (JRehling @ Jun 11 2015, 12:15 AM) *
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.


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.

Posted by: dudley Jun 12 2015, 01:27 AM

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.

Posted by: Phil Stooke Jun 12 2015, 01:51 AM

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.



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



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

Phil

Posted by: ChrisC Jun 12 2015, 02:59 AM

QUOTE (Explorer1 @ Jun 11 2015, 06:06 PM) *
Media schedule is out now; quite busy! http://www.nasa.gov/press-release/nasa-announces-television-coverage-media-activities-for-pluto-flyby

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!

Posted by: Tom Tamlyn Jun 12 2015, 05:03 AM



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)

Posted by: Daniele_bianchino_Italy Jun 12 2015, 08:51 AM

QUOTE (Phil Stooke @ Jun 12 2015, 12:11 AM) *
These are the frames taken from the new video, giving a full rotation.

Phil




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


Posted by: pitcapuozzo Jun 12 2015, 12:36 PM

QUOTE (Daniele_bianchino_Italy @ Jun 12 2015, 10:51 AM) *
What kind of energy can 'cause Pluto in CHaron and Charon in Pluto?
marea force?


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.

Posted by: Daniele_bianchino_Italy Jun 12 2015, 12:41 PM

QUOTE (pitcapuozzo @ Jun 12 2015, 12:36 PM) *
Do you mean tidal forces?


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

Posted by: JRehling Jun 12 2015, 03:33 PM

QUOTE (Aldebaran @ Jun 11 2015, 06:10 PM) *
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.


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.

Posted by: scalbers Jun 12 2015, 03:47 PM

QUOTE (pitcapuozzo @ Jun 12 2015, 12:36 PM) *
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.

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.

Posted by: dvandorn Jun 12 2015, 06:27 PM

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.

Posted by: dudley Jun 12 2015, 11:11 PM

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.

Posted by: nprev Jun 12 2015, 11:16 PM

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. wink.gif

Posted by: dvandorn Jun 13 2015, 12:49 AM

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... wink.gif

-the other Doug


Posted by: Phil Stooke Jun 13 2015, 01:03 AM

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


Posted by: ZLD Jun 13 2015, 04:20 AM

2015-6-11 - 4 stacked with deconvolution



Heres the stacked image without deconvolution as well.



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


Posted by: Alan Stern Jun 14 2015, 12:09 PM

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

 

Posted by: Ian R Jun 14 2015, 02:04 PM

Great news, Alan: thank for the update!

Posted by: 0101Morpheus Jun 14 2015, 02:50 PM

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

Posted by: Bill Harris Jun 14 2015, 03:48 PM

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

--Bill

Posted by: Phil Stooke Jun 15 2015, 04:07 AM

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

Phil


Posted by: jgoldader Jun 15 2015, 10:44 AM

QUOTE (Phil Stooke @ Jun 14 2015, 11:07 PM) *
This is a composite of the four June 13th LORRI frames


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.

Posted by: Bjorn Jonsson Jun 15 2015, 10:45 PM

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.



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...

Posted by: alk3997 Jun 16 2015, 02:17 AM

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.



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-Encounter/view_obs.php?image=data/pluto/level2/lor/jpeg/029665/lor_0296650333_0x630_sci_1.jpg&utc_time=2015-06-15%3Cbr%3E05:00:15%20UTC&description=OpNav+Campaign+4%2C+LORRI+1X1&target=PLUTO&range=34.9M%20km&exposure=100%20msec

Andy

Posted by: Phil Stooke Jun 16 2015, 02:43 PM

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


Posted by: ZLD Jun 16 2015, 02:50 PM

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



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



Lots of details becoming visible here.

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