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MahFL
The LORRI image release for today is up at :

http://pluto.jhuapl.edu/News-Center/News-A...p?page=20150204


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

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

Looking at Solar System Simulator (one, two) 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.
MarsInMyLifetime
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.
john_s
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
Bjorn Jonsson
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:

Click to view attachment

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:

Click to view attachment


jgoldader
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!
elakdawalla
For painful detail on the issue of Pluto cartography, read my blog entry about Amanda Zangari's work on this or her recently published paper (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.
Bjorn Jonsson
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!
alk3997
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
alk3997
New Pluto/Charon animation available from end of January:
http://www.nasa.gov/content/the-view-from-...ml#.VN0cuvnF98H

jasedm
For those members (and I include myself) who are not entirely au-fait with celestial mechanics, I found these animations very useful in making sense of the Pluto/Charon orbital dance in the latest opnav campaign images. (Scroll up).....

Jase
john_s
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: Nix and Hydra movie release

John
alk3997
QUOTE (john_s @ Feb 18 2015, 11:14 AM) *
And here they are: Nix and Hydra movie release

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
algorimancer
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?

Click to view attachment
john_s
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
peter59
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.
Click to view attachment
nprev
Alan just announced on social media that the recent TCM was nominal. smile.gif
Habukaz
Now, if I've understood this blogpost 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
mcgyver
QUOTE (Habukaz @ Mar 23 2015, 04:11 PM) *
Now, if I've understood this blogpost 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 this blog post, the Hubble limit is around 800 km/pixel and Pluto being 3 pixel large, but according to this page, at least 250 km/pixel resolution (pluto ~=10 pixel) can be reached by processing, obtaining these images:

http://www.nasa.gov/mission_pages/hubble/s...o-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-lakda...to-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-lakda...pectations.html
machi
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).

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

https://twitter.com/NewHorizons2015/status/...766844947456000
tedstryk
QUOTE (mcgyver @ Mar 30 2015, 09:20 AM) *
It is not very clear to me when the "Hubble limit" will be crossed: according to this blog post, the Hubble limit is around 800 km/pixel and Pluto being 3 pixel large, but according to this page, 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).
jgoldader
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.
Explorer1
A pair of briefings coming up next week:

http://www.nasa.gov/press/2015/april/nasa-...ssion-to-pluto/
Explorer1
Presser on now: color images released!

http://www.nasa.gov/multimedia/nasatv/index.html
alk3997
First color New Horizon's image of Pluto/Charon:

Click to view attachment

http://pluto.jhuapl.edu/News-Center/News-A...p?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
Explorer1
I would be loath to make any interpretations; this still isn't BTH (Better Than Hubble), for now.
Habukaz
With MVIC, Pluto is currently...what, 1-2 pixels across?
elakdawalla
MVIC resolution in that image is 2274 km, just a bit under 1 Pluto diameter.
Marvin
Slightly larger version of the color image, found on Twitter:

Click to view attachment

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
ngunn
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.

belleraphon1
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...
Webscientist
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.




Gerald
For anyone who missed part of the briefings, here links to recorded versions:
First briefing, part 1, 02:40:06 - 02:59:58.
First briefing part 2, 00:00:00 - 00:38:42.
A prevously recorded version of the second briefing, 01:40:24 - 02:37:07.
Webscientist
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?

Phil Stooke
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
Webscientist
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

4throck
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.
alk3997
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
jgoldader
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.
Paolo
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?
Landru79
QUOTE
Webscientist

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


¿Maybe a phase efect?
Hungry4info
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.
djellison
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.
JohnVV
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 --
Paolo
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
mcgyver
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..."
Webscientist
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.

TheAnt
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
alk3997
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
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