Pluto Surface Observations 1: NH Post-Encounter Phase, 1 Aug 2015- 10 Oct 2015 |
Pluto Surface Observations 1: NH Post-Encounter Phase, 1 Aug 2015- 10 Oct 2015 |
Sep 17 2015, 06:49 PM
Post
#271
|
||
Senior Member Group: Members Posts: 1630 Joined: 5-March 05 From: Boulder, CO Member No.: 184 |
Congratulations John S. and all on the NH Team! Here's a rough context for the center-right region in the new crescent image, taken from my latest map, of course with more of an overhead perspective.
The orientation is roughly the same with the context view being rotated a bit counter-clockwise from the crescent image. The terminator of the crescent is located near the bottom of the context image. It's interesting to correlate features of the Hillary Montes (on the limb) and adjacent Sputnik Planum between both images. -------------------- Steve [ my home page and planetary maps page ]
|
|
|
||
Sep 17 2015, 07:20 PM
Post
#272
|
||
Senior Member Group: Members Posts: 4246 Joined: 17-January 05 Member No.: 152 |
Yikes! Being ever the sceptic, my first thought when seeing the crescent image was: "Oh, too bad, they brightened the atmosphere selectively to make the image more dramatic." But there's no mention of that in the caption. And no sign of that when you examine the image closely. Indeed the relative brightness of the "fogbank" (which clearly has not been brightened) compared with the sky looks reasonable, considering the relative optical depths.
Here's my attempt at bringing out detail in the dark regions. I've done some quick-and-dirty FFT filtering to suppress the faint banding (after rotation by 12.2 deg to make the banding horizontal) and a stretch: There is some residual horizontal banding. But there are crepuscular rays clearly visible mainly on the left half of the frame. It's also cool how you can see stars and the sunlit disk at the same time (another reason I was sceptical of the image). I'm sure many of us are annoyed whenever we see renderings of the sunlit disk of the Earth, say, with stars or the Milky Way visible. But I guess that's possible with a thousandth of the solar illumination levels at the Earth. I tried to put a circle to determine the height of various points on the limb: Interestingly, the left edge descends sharply. If the mosaicing wasn't done perfectly, you'd expect departures from a circular limb.
|
|
|
||
Sep 17 2015, 07:33 PM
Post
#273
|
|
Junior Member Group: Members Posts: 82 Joined: 13-July 15 Member No.: 7579 |
If the mosaicing wasn't done perfectly, you'd expect departures from a circular limb. This frame is not a mosaic, just one frame, but you're right, the raw data should be severely distorted by motion relative Pluto during scaning time and a distortion was compensated in image processing. |
|
|
Sep 17 2015, 07:49 PM
Post
#274
|
|
Member Group: Members Posts: 714 Joined: 3-January 08 Member No.: 3995 |
|
|
|
Sep 17 2015, 07:57 PM
Post
#275
|
|
Senior Member Group: Members Posts: 1630 Joined: 5-March 05 From: Boulder, CO Member No.: 184 |
It seems to me the "fog" layer is comparable in height with the topography, due to the fairly high shadow contrast. Also, the fog layer has a higher scattering/extinction coefficient (i.e. optically denser) than the overall planetwide haze layer. The optical thickness of each may be comparable though.
-------------------- Steve [ my home page and planetary maps page ]
|
|
|
Sep 17 2015, 08:05 PM
Post
#276
|
|
Junior Member Group: Members Posts: 48 Joined: 10-September 06 Member No.: 1129 |
My attempt to add color using the earlier MVIC coverage: [attachment=37873:Pluto_Ba...IC_Color.jpg] This new image from New Horizons is incredible. And this is a stunning coloring, Ian. Would you or someone else be able to do the same for the full high-res image that I can't stop staring at? https://www.nasa.gov/sites/default/files/th...-15-final_0.png |
|
|
Sep 17 2015, 08:23 PM
Post
#277
|
||
Senior Member Group: Members Posts: 1630 Joined: 5-March 05 From: Boulder, CO Member No.: 184 |
Yes, and I have always believed that Cthulhu - a smooth ice surface, which looks dark when viewed from the side of the sun will shine if the angle of incidence equals the angle of reflection. [attachment=37877:Ctulhu.jpg] I'm still correlating darker regions in the crescent image with Cthulu areas and brighter regions in the crescent with some of the immediately adjacent Sputnik Planum areas. It seems that the correlation of reflectance is mostly preserved at the different viewing angles, except that parts of Sputnik Planum look darker in the new image. I'll have to try to annotate these images perhaps with corresponding features in some detail. Here is a start for this... -------------------- Steve [ my home page and planetary maps page ]
|
|
|
||
Sep 17 2015, 08:31 PM
Post
#278
|
|
Senior Member Group: Members Posts: 1276 Joined: 25-November 04 Member No.: 114 |
Amazing!
Pluto is now my 2nd favorite after Europa. |
|
|
Sep 17 2015, 08:36 PM
Post
#279
|
|
Lord Of The Uranian Rings Group: Members Posts: 798 Joined: 18-July 05 From: Plymouth, UK Member No.: 437 |
This new image from New Horizons is incredible. And this is a stunning coloring, Ian. Would you or someone else be able to do the same for the full high-res image that I can't stop staring at? I'm happy to take a crack at it! -------------------- |
|
|
Sep 17 2015, 08:45 PM
Post
#280
|
||
Senior Member Group: Members Posts: 4246 Joined: 17-January 05 Member No.: 152 |
This frame is not a mosaic, just one frame, but you're right, the raw data should be severely distorted by motion relative Pluto during scaning time and a distortion was compensated in image processing. Thanks - I see we expect 5000 pix wide images. The total integration time is supposed to be 0.4 s for the pan band, I think for a full disk. But this is much less than a full disk so the time should've been correspondingly smaller. So perhaps distortions due to spacecraft motion are quite small. Also, fov should be a few degrees for the released image, so geometrical distortions may be small. Why do you say distortion was compensated? I thought the image was a mosaic because I noticed discontinuities. If you look closely you can see a discontinuity in the horizontal banding pattern running from roughly 1 to 7 o'clock across this crop: I guess that's somehow related to the operation of the camera. |
|
|
||
Sep 17 2015, 08:56 PM
Post
#281
|
||
Junior Member Group: Members Posts: 80 Joined: 14-February 04 Member No.: 32 |
Thanks - I see we expect 5000 pix wide images. The total integration time is supposed to be 0.4 s for the pan band, I think for a full disk. But this is much less than a full disk so the time should've been correspondingly smaller. So perhaps distortions due to spacecraft motion are quite small. Also, fov should be a few degrees for the released image, so geometrical distortions may be small. Why do you say distortion was compensated? I thought the image was a mosaic because I noticed discontinuities. If you look closely you can see a discontinuity in the horizontal banding pattern running from roughly 1 to 7 o'clock across this crop: I guess that's somehow related to the operation of the camera. The entire wide image seems to have the same regular banding, in the same direction. I'm surprised they didn't try to filter that out - or compensate for it. Has anyone tried doing that? -------------------- - Lars
|
|
|
||
Sep 17 2015, 09:24 PM
Post
#282
|
|
Junior Member Group: Members Posts: 53 Joined: 15-July 09 Member No.: 4867 |
Can't wait to work with the 12bits images, there will so much more possibilities in terms of dark/bright zones analysis.
And it's funny to see how sharp the shadows are, due to the small apparent size of the sun. |
|
|
Sep 17 2015, 09:39 PM
Post
#283
|
|
Senior Member Group: Members Posts: 4246 Joined: 17-January 05 Member No.: 152 |
|
|
|
Sep 17 2015, 09:48 PM
Post
#284
|
|
Junior Member Group: Members Posts: 75 Joined: 8-July 15 Member No.: 7566 |
Something I haven't seen mentioned yet:
There's a lot more to the right side of the Heart then we've seen before. I'm guessing that part came from as of yet unreleased images? |
|
|
Sep 17 2015, 09:57 PM
Post
#285
|
|
Member Group: Members Posts: 423 Joined: 13-November 14 From: Norway Member No.: 7310 |
Nah, I think e.g. images like these are adequate:
http://pluto.jhuapl.edu/soc/Pluto-Encounte...mgType=approved http://pluto.jhuapl.edu/soc/Pluto-Encounte...mgType=approved + even older ones at lower resolution for the eastmost part. -------------------- |
|
|
Lo-Fi Version | Time is now: 1st May 2024 - 10:28 AM |
RULES AND GUIDELINES Please read the Forum Rules and Guidelines before posting. IMAGE COPYRIGHT |
OPINIONS AND MODERATION Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators. |
SUPPORT THE FORUM Unmannedspaceflight.com is funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member. |